PETRONAS TECHNICAL STANDARDS DESIGN AND ENGINEERING PRACTICE

(CORE)

MANUAL

DESIGN AND INSTALLATION OF CHEMICAL- RESISTANT LININGS FOR

CONCRETE STRUCTURES

PTS 30.48.60.12

AUGUST 2000

PREFACE

PETRONAS Technical Standards (PTS) publications reflect the views, at the time of publication,of PETRONAS OPUs/Divisions.

They are based on the experience acquired during the involvement with the design, construction,operation and maintenance of processing units and facilities. Where appropriate they are basedon, or reference is made to, national and international standards and codes of practice.

The objective is to set the recommended standard for good technical practice to be applied byPETRONAS' OPUs in oil and gas production facilities, refineries, gas processing plants, chemicalplants, marketing facilities or any other such facility, and thereby to achieve maximum technicaland economic benefit from standardisation.

The information set forth in these publications is provided to users for their consideration anddecision to implement. This is of particular importance where PTS may not cover everyrequirement or diversity of condition at each locality. The system of PTS is expected to besufficiently flexible to allow individual operating units to adapt the information set forth in PTS totheir own environment and requirements.

When Contractors or Manufacturers/Suppliers use PTS they shall be solely responsible for thequality of work and the attainment of the required design and engineering standards. Inparticular, for those requirements not specifically covered, the Principal will expect them to followthose design and engineering practices which will achieve the same level of integrity as reflectedin the PTS. If in doubt, the Contractor or Manufacturer/Supplier shall, without detracting from hisown responsibility, consult the Principal or its technical advisor.

The right to use PTS rests with three categories of users :

1) PETRONAS and its affiliates.2) Other parties who are authorised to use PTS subject to appropriate contractual

arrangements.3) Contractors/subcontractors and Manufacturers/Suppliers under a contract with

users referred to under 1) and 2) which requires that tenders for projects,materials supplied or - generally - work performed on behalf of the said userscomply with the relevant standards.

Subject to any particular terms and conditions as may be set forth in specific agreements withusers, PETRONAS disclaims any liability of whatsoever nature for any damage (including injuryor death) suffered by any company or person whomsoever as a result of or in connection with theuse, application or implementation of any PTS, combination of PTS or any part thereof. Thebenefit of this disclaimer shall inure in all respects to PETRONAS and/or any company affiliatedto PETRONAS that may issue PTS or require the use of PTS.

Without prejudice to any specific terms in respect of confidentiality under relevant contractualarrangements, PTS shall not, without the prior written consent of PETRONAS, be disclosed byusers to any company or person whomsoever and the PTS shall be used exclusively for thepurpose they have been provided to the user. They shall be returned after use, including anycopies which shall only be made by users with the express prior written consent of PETRONAS.The copyright of PTS vests in PETRONAS. Users shall arrange for PTS to be held in safecustody and PETRONAS may at any time require information satisfactory to PETRONAS in orderto ascertain how users implement this requirement.

TABLE OF CONTENTS

1. INTRODUCTION 1.1 SCOPE 1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS 1.3 DEFINITIONS 1.4 CROSS-REFERENCES 1.5 SUMMARY OF MAIN CHANGES SINCE PREVIOUS EDITION 2. SELECTION CRITERIA FOR CHEMICAL-RESISTANT LININGS 2.1 GENERAL 2.2 SELECTION CRITERIA 3. CHEMICAL-RESISTANT LINING MATERIALS 3.1 MEMBRANES 3.2 CEMENTS AND MORTARS 3.3 CHEMICAL-RESISTANT BRICKS AND TILES 4. LINING, COATING SELECTION AND DESIGN 4.1 GENERAL 4.2 NON-LINED CONCRETE SYSTEMS 4.3 JOINTLESS (FLOOR) PROTECTION SYSTEMS 4.4 CHEMICAL-RESISTANT BRICK LINING SYSTEMS 4.5 TRENCHES 4.6 NEUTRALISATION PITS 4.7 DRAINAGE AND PRIMARY TREATMENT FACILITIES 4.8 CONCRETE VESSELS 4.9 PROTECTION SYSTEMS FOR MISCELLANEOUS CONSTRUCTIONS 5. HANDLING AND STORAGE OF LINING MATERIALS 6. LINING INSTALLATION 6.1 SURFACE PREPARATION FOR CONCRETE SURFACES 6.2 EXPANSION JOINTS 6.3 MEMBRANES 6.4 MORTARS 6.5 BRICKS AND TILES 6.6 JOINTLESS (FLOOR) SYSTEMS 7. HEALTH, SAFETY AND ENVIRONMENTAL (HSE) ASPECTS 8. QUALITY CONTROL 9. INSPECTION BEFORE AND AFTER INSTALLATION 10. MAINTENANCE AND REPAIR 11. REFERENCES 12. BIBLIOGRAPHY

APPENDICES APPENDIX 1 SPECIFICATION FOR MATERIALS, SAMPLING, TESTING AND

PACKAGING

1. INTRODUCTION

1.1 SCOPE

This PTS specifies requirements and gives recommendations for the design, installation, testing and inspection of chemical-resistant linings for concrete structures used in the petroleum, chemical and gas industries.

This PTS is a revision of the PTS of the same number dated May 1993 and has incorporated PTS 30.48.60.33, which is now withdrawn. A summary of the main changes since the previous edition of this PTS is given in (1.5).

Excluded from the scope of this PTS are rubber linings, for which reference is made to PTS 30.48.60.10, and (acid-resistant) refractory bricks and shapes, for which reference is made to PTS 44.24.90.31 Chemical-resistant linings for process equipment are covered by PTS 30.48.60.13 Painting and coating systems are covered by PTS 30.48.00.31

This PTS principally covers ceramic types of lining materials (e.g. bricks, tiles and mortars) and their underlying membranes, but also non-ceramic linings such as synthetic-resin-based systems.

Chemical-resistant ceramic linings are used to protect concrete elements (such as floors and gutters) against chemical attack. A combination of a ceramic lining and a membrane is mostly used for this purpose. The membrane is designed to prevent penetration of chemicals to the underlying concrete surface. The ceramic lining serves to protect the membrane against chemical, mechanical and/or thermal loads (e.g. scaffolding, steam cleaning).

It is not the intention of this PTS to provide detailed specifications for the various cases of chemical attack. Each case shall be looked at individually and, based on these minimum requirements, details shall be worked out and agreed between the Principal, the Contractor, the Manufacturer and the Applicator, leading to a durable protection of concrete structures against chemical attack under the particular conditions.

The specified properties shall be tested in accordance with internationally accepted standards, or local standards if they exist. For convenience, specific standards are mentioned in various cases.

For a further comparison of the chemical resistance between the materials, reference is made to PTS 30.10.02.13 NOTE: In various places in this PTS specific brands of products are specified. It is not intended to preclude the

use of other products; equivalent products may be used provided the Principal so approves.

1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS

Unless otherwise authorised by PETRONAS, the distribution of this document is confined to companies forming part of or managed by the PETRONAS Group, and to Contractors nominated by them.

This PTS is intended for use in oil refineries, chemical plants, gas plants, and, where applicable, in supply/marketing installations and exploration and production facilities.

If national and/or local regulations exist in which some of the requirements may be more stringent than this PTS, the Contractor shall determine by careful scrutiny which of the requirements are the more stringent and which combination of requirements will be acceptable as regards safety, economic and legal aspects. In all cases the Contractor shall inform the Principal of any deviation from the requirements of this document which is considered to be necessary in order to comply with national and/or local regulations. The Principal may then negotiate with the Authorities concerned with the object of obtaining agreement to follow this document as closely as possible.

1.3 DEFINITIONS

The Applicator is the party which applies the chemical-resistant linings specified by the Contractor.

The Contractor is the party which carries out all or part of the design, engineering, procurement, construction and commissioning for a project or operation of a facility. The Principal may undertake all or part of the duties of the Contractor.

The Manufacturer/Supplier is the party which manufactures or supplies equipment and services to perform the duties specified by the Contractor.

The Principal is the party which initiates the project and ultimately pays for its design and construction. The Principal will generally specify the technical requirements. The Principal may also include an agent or consultant, authorised to act for the Principal.

The word shall indicates a requirement. The word should indicates a recommendation.

1.4 CROSS-REFERENCES

Where cross-references to other parts of this PTS are made, the referenced section number is shown in brackets. Other documents referenced in this PTS are listed in (11).

1.5 SUMMARY OF MAIN CHANGES SINCE PREVIOUS EDITION

The previous edition of this PTS was dated May 1993. This edition was made primarily to incorporate the contents of PTS 30.48.60.33, which is now withdrawn. There have been no significant technical changes in this edition.

2. SELECTION CRITERIA FOR CHEMICAL-RESISTANT LININGS

2.1 GENERAL

Concrete is a mixture of hydraulic cement and mineral aggregates, of which the cement is the constituent in the mix most vulnerable to chemical attack. Because the concrete has a relatively high open porosity and concrete surfaces become increasingly permeable over time, attack on the underlying reinforcement becomes a major risk as well.

The alkaline character of the cement in the mix provides the concrete with a good resistance against alkalis. However, if concrete is exposed to acids, acidic solutions or an acid/alkaline condition, protection by means of a chemical-resistant lining may be required.

Concrete is resistant to most hydrocarbon solvents.

Structural and other steels not only have limited resistance against chemical loads, but are often susceptible to various systems of stress corrosion cracking or embrittlement. Under specific conditions special steels can be used for use with chemicals.

A chemical-resistant lining will, in general, consist of at least two lines of defence, i.e. a membrane and a chemical-resistant lining. The optimal solution is bricks or tiles laid in a synthetic resin-based mortar with a suitable membrane, but this type of construction is expensive and should only be applied when justified. Less expensive solutions, consisting of one or more layers of a synthetic-resin-based system, either with or without a reinforcement, or full plastic-sheet membranes which are mostly proprietary systems, can be applied but should be justified as well.

Where possible, alternative cheaper solutions, such as bricks or tiles laid in silicate-based mortars, jointless protective layers, or a combination thereof should be used.

A well-prepared concrete surface is essential for the proper performance of chemical-resistant linings. The installation of these linings shall be carried out by specialised contractors with skilled labour under stringent supervision. The installation shall be completed with a suitable after-treatment.

Precautions shall be taken to avoid inadvertent outflow/disposal of chemicals (e.g. hydrochloric acid used for cleaning dirty floors, "acidulation" of brick lining, etc.).

For an initial selection of a chemical-resistant lining Table 2-1 may be used as guidance. For further and/or detailed comparisons or selections reference is made to PTS 30.10.02.13 Chemical-resistant lining materials shall comply with Appendix 1 and PTS 30.10.02.13

2.2 SELECTION CRITERIA

The need for a chemical-resistant protection and the selection of the type of protection required for the envisaged duty shall be based on:

Service/operating conditions or environment - of prime importance are the nature, composition and temperature of the chemicals

against which a construction shall be protected. Exact knowledge is required of the behaviour of these chemicals and the materials for which protection is required;

Existing (mechanical as well as chemical) load - taking into account not only the present situation but also any future changes,

thereby avoiding expensive alterations;

Condition of construction/installation - this often has a decisive influence on the costs. Each material or construction

requires greatly differing working conditions, e.g. temperature, dryness, ventilation, material-specific required sequences, etc.;

Economics - the most economical lining is the one which is adequately resistant to the loads that

arise and is quickly and cheaply applied, thus being likely to achieve the desired service life;

Service life - it is economically not justifiable to select protections which will outlive the

constructions they must protect. Sometimes it may be better to use a simple, inexpensive application, even one requiring minor repairs, rather than more reliable and sophisticated but costly applications;

Selection results - besides the above criteria, thorough consideration should be given to specific site

and operational conditions, and the required safety margins within which operations and/or the effectiveness of the protection can vary;

Types of chemical-resistant material - in general terms as low, medium (normal) and high protection, or as types (in

ascending order), e.g. impregnation, sealing, coatings, fillers, synthetic resin screeds, tiles in various types of mortars, including possible combinations.

Table 2-1: Comparison of the chemical resistance of various materials at 20 C

Water Hydrocarbons

Amm

onia

liqu

id 2

5%

Hyd

roch

loric

aci

d 35

%

Sulp

huric

aci

d 98

%

Nitr

ic a

cid

25%

Hyd

roflu

oric

aci

d 50

%

Oth

er s

alts

Chl

orin

ated

Brac

kish

Pota

ble

Alka

lis

Sulp

hate

s

Chl

orid

es

Alip

hatic

Arom

atic

Keto

nes

Min

eral

oils

Alco

hols

Este

rs

Phen

ols

Concrete based on:Portland cement - (+) + + - - -- ++- - +++ +-+-Portland blast-furnace cement + + + + - - -- ++(+) (+) +++ +-+-High-alumina cement + + + - - - -- ++(+) + +++ ++--Sulphate resisting Portland cement + + + + - - -- ++(+) + +++ +++-

Protective membranes:Asphaltic bitumen + + + + +

up to30%

-up to50%

-+1] (+) -- - -+++ --

Poly-isobutylene sheet + + + + + --+ + -- - ++++ (+)+Cold-cured epoxy + + + + + +-+1] + ++ + ++++ -+Mortar/coating based on:Phenol-furfuraldehyde resin + + + + + + - + 1] (+) + + + + ++ ++ + +Phenol-formaldehyde resin + + + + + - - + 1] + + + + + ++ ++ + +Furane resin + + + + + - - + 1] + + + + + ++ ++ + +Epoxy resin + + + + + - (+) - + + + + + +- ++ (+) -

Polyester resin + + + + + - (+) (+)1] (+) + + + + +(+) ++ (+) -

Sodium silicate 2 ] - - - - + (+) + - - (+) + (+)3] + ++ ++ + +

Potassium silicate 2 ] - - - - + + + - - + (+) (+)3] + ++ ++ + +

(+)(+)(+)

(+)

+

(+)-

+++++++

Sea

+

++

+ Resistant (+) Resistant to a limited extent - Not resistant

NOTES: 1. The filler shall also be resistant.

2. Has a porosity of 7 - 16% and should never be used as a membrane.

3 Sodium and potassium silicate cements are not resistant to ammonium fluoride and sodium bicarbonate.

Although concrete has a certain degree of chemical resistance (4.2) it should be treated as a substrate to be protected. The selection of the type of concrete shall be primarily based on structural considerations, with its chemical resistance as a bonus.

3. CHEMICAL-RESISTANT LINING MATERIALS

3.1 MEMBRANES

3.1.1 General

The following materials should be used as membranes for concrete structures: asphaltic bitumen; thermoplastic materials; thermosetting materials.

Acid-resisting brick lining for floors, and bottoms of pits (e.g. neutralisation pits) or vessels and trenches shall be provided with membranes which can sustain mechanical loads. NOTE: Mechanical loads may be induced by, for instance:

the use of high pressure cleaning equipment;

mechanical cleaning equipment;

mobile transport, equipment, etc.

3.1.2 Asphaltic bitumen membranes

The asphaltic bitumen used for the construction of membranes has good physical properties and fair resistance against mineral acids (except hydrofluoric acid and low concentrations of oxidising acids).

Asphaltic bitumen is not resistant to oils, grease and solvents (except alcohols). Generally it shall not be exposed to temperatures in excess of 60 C.

The selection of the type of asphaltic membrane is determined by the loading expected on the floor.

3.1.3 Thermoplastic membranes

Unless otherwise specified, only thermoplastic membranes based on polyisobutylene shall be used. Polyisobutylene sheet lining provides a good liquid-tight membrane. It shall be adhesive-bonded to the substrate and the joints shall be sealed either by an adhesive or by fusion welding; vulcanisation is not required.

Polyisobutylene only has a fair resistance against hydrocarbon solvents. NOTE: Thermoplastic membranes are generally too rigid to accommodate irregularities of the concrete

substrate, unless they are used as "false form work".

3.1.4 Thermosetting membranes

For specific chemical conditions a synthetic resin-based membrane shall be used (with or without a fibre reinforcement).

An optimum chemical resistance may be obtained by selection of an appropriate synthetic resin.

3.2 CEMENTS AND MORTARS

3.2.1 Mortars based on hydraulic cements

Hydraulic mortars are generally used in building construction.

These mortars can be used as bedding mortar for tiles in mildly aggressive conditions.

Furthermore, layers of these mortars can be applied to structures to provide slopes for drainage. However, layers shall be suitably proportioned to reduce the risk of possible delamination or spalling. It should be good practice to incorporate the required slope or level already in the finished structural concrete or equipment.

3.2.2 Silicate-based mortars

Silicate-based mortars are commonly used for the construction of acid-resistant brick linings.

If contact with sulphuric acid is expected, potassium silicate-based mortar is preferred to sodium silicate-based mortar (see notes). NOTES: 1. Under these conditions the sodium sulphate, formed in the sodium silicate mortar, crystallises with

an increase in volume due to the release of crystallisation water. Potassium sulphate, on the other hand, crystallises without increase of volume.

2. Halogen-containing silicate-based mortars may, in contact with strong acids, produce hydrofluoric acid which would attack the substrate in direct contact with it. For such conditions, halogen-free silicate-based cements have been developed.

3. The porosity of silicate-based mortars, which is between 7% and 16% depending on the type, is a major disadvantage and therefore they shall not be used as a membrane.

4. Silicate-based mortar may be used as a bedding material, applied on an asphaltic bitumen membrane. The joints between brick and tiles should then be sealed with a synthetic resin-based mortar.

Mildly alkaline media can be tolerated at ambient temperature after careful "acidulation" of the mortar. Alternating acid and alkaline service, however, cannot be tolerated.

Silicate-based mortars have only slight resistance against erosion, especially from flowing hot water, steam or alkali. Washing out of mortar from the joints may occur. The use of other types of mortar, mainly synthetic-resin-based, shall then be considered for jointing and laying the bricks.

A properly mixed fresh mortar reacts readily and cures even when air is excluded. During reaction and curing the mortar remains soluble and shall be protected against rain or other possible wash-out by water.

Silicate mortars do not adhere to rubber membranes.

3.2.3 Synthetic-resin-based mortars

Synthetic-resin-based mortars are commonly used for the construction of acid-resistant brick linings. They cure as a result of a chemical reaction between the synthetic resin and a curing agent. They adhere very well to a rubber membrane.

The main types are filled phenolic, furane, polyester and/or epoxy-resin-based cements.

Phenolic-resin-based mortars, when properly applied, are erosion resistant and free of pores. They can be used both as a membrane and for embedding and sealing the joints between bricks or tiles. The modified phenolic-resin-based mortars provide excellent resistance against both acidic and alkaline conditions and have good resistance against mildly oxidising solutions.

In general the properties of furane-resin-based mortar resemble those of mortars based on phenol resin, but curing at high temperatures is not required to obtain full chemical resistance. The furane-resin-based mortars have good chemical resistance. If a filler such as graphite is added, resistance against hydrofluoric acid is also obtained. Furane-resin-based mortars are erosion resistant and free of pores when properly applied.

Polyester-resin-based mortars have good chemical and erosion resistance.

Epoxy-resin-based mortars can be used for continuous floors and for embedding and sealing purposes. An outstanding characteristic of epoxy-resin-based mortars is their very good adhesion. For their application on a concrete substrate no pre-treatment other than proper surface cleaning is necessary.

3.3 CHEMICAL-RESISTANT BRICKS AND TILES

3.3.1 General Bricks and tiles are manufactured to standard sizes which shall be used whenever possible to save costs.

Tiles used for floors, trenches and neutralisation pits shall be at least 30 mm thick.

For walls in pump houses, etc. glazed, split tiles or similar shall be used. The minimum thickness of the tiles should be 20 mm.

Bricks and tiles shall have a roughened, non-glazed surface finish or split dove-tailed grooves that optimise adhesion of the mortar at the faces to be embedded.

Some acid-resistant bricks have low resistance against penetration of liquids and/or gases, as against high thermal conductivity and consequently often good thermal shock resistance. Attention shall be paid to their open porosity particularly if crystallising liquids may be present where a potential danger of crystal growth within the pores can occur, resulting in expansion and subsequent destruction of the brick.

Other bricks resist the penetration of liquids, in conjunction with low thermal conductivity (closed porosity); hence, high thermal gradients within the brick can occur and subsequent temperature shock will lead to thermal spalling.

Erosion resistance of the bricks and tiles shall be considered, if required.

Mechanical and physical properties of various chemical-resistant lining materials are given in Appendix 1.

3.3.2 Acid-resistant bricks and tiles

Bricks commonly used in a chemical-resistant brick lining are silica-alumina type acid-resistant bricks as specified in Appendix 1.

3.3.3 Carbon bricks

Carbon bricks as specified in Appendix 1 shall be used for the following:

if hydrofluoric acid is present;

alkali solutions with a mass fraction greater than 0.2;

alkali solutions at temperatures above 20 C.

Carbon has a moderate thermal conductivity and is very hard. These properties make it an excellent material for corrosive and erosive services with high thermal loads. For these conditions non-impregnated carbon bricks may be used, relying on mortars and membrane to protect the concrete effectively.

3.3.4 Special ceramic materials

The use of these special ceramic materials, as specified in Appendix 1, are in principle allowed but the Manufacturer/Supplier shall prove evidence of the long term reliability of such systems to the Principal.

4. LINING, COATING SELECTION AND DESIGN

4.1 GENERAL

Chemical-resistant linings for concrete structures shall be designed and installed by a qualified and experienced engineering contractor only. The need for such linings shall be taken into account early in the design and calculation stages of the structure, so that the required slope for drainage of floors, trenches and other provisions, and the additional weight of the lining, can be considered.

If a chemical-resistant lining has to be applied at a later stage, due to a change in requirements or the extension of an installation, the concrete structure or equipment shall be recalculated for the additional loads and/or the thermo-mechanical stresses.

If a change in chemical conditions from those originally anticipated in the design is envisaged, the effects on the chemical-resistant lining shall be carefully scrutinised.

It is stressed that optimal chemical-resistant properties will only be achieved when maximum attention is paid to the use of appropriate materials and installation requirements.

Prior to the application of lining systems, concrete vessels, sumps, pits etc., shall be water tested to ensure liquid tightness in accordance with PTS 34.19.20.31

4.2 NON-LINED CONCRETE SYSTEMS

4.2.1 General For the design and construction of reinforced concrete structures reference is made to PTS 34.19.20.31

Hydraulic cements used in concrete and mortars as described below shall be in accordance with Appendix 1.

The degree of chemical resistance of concrete based on these types of cement largely depends on the composition of the mix.

Only concrete of high density and proper selected composition may be expected to provide good resistance against alkalis, solvents, etc.

4.2.2 Concrete based on normal Portland cement

Normal Portland cement is generally used for concrete constructions, in mortars for ordinary brick laying and if the concrete is exposed to mildly alkaline conditions.

4.2.3 Concrete based on Portland blast-furnace cement

For concrete and mortars exposed to a chloride environment (such as brackish and/or sea water) this type of cement should be considered.

4.2.4 Concrete based on sulphate-resisting Portland cement

Where concrete and mortars are exposed to sulphates, or traces of sulphuric acid up to 0.5% by weight, and/or alkaline solutions up to about pH =12, the use of this type of cement should be considered. Reference is also made to PTS 34.19.20.31, Appendix 1 tables 2 and 3.

4.2.5 Concrete based on High-Alumina cement

This type of cement is slightly resistant to diluted acids. It has a poor resistance to alkaline solutions with a pH >9.

High-alumina cement may be used only for non-structural applications, and requires the approval of the Principal.

4.3 JOINTLESS (FLOOR) PROTECTION SYSTEMS

4.3.1 General Although the following descriptions mainly relate to application on floors, they can also be applicable to adjacent walls, corbels, foundation blocks, columns, etc., which are subject to the same chemical loads.

Chemical-resistant floors can be subdivided as follows: Floors without continuous chemical attack

Concrete constructions, e.g. floors, without a finish layer can produce considerable dust when they are dry. Moreover, they are vulnerable to incidental spillage of e.g. oils, fat and various chemicals. For such conditions an epoxy lining system, optionally fibre-reinforced, should be used (4.3.3 and 4.3.4).

Acid-resistant floors Floors for acid service only and not exposed to traces of alkali, steam or hot water shall be provided with a layer of bricks or tiles, which are laid in silicate-cement-based bedding mortar on the selected membrane. The thickness of the mortar layer should be 3 - 5 mm. When the mortar has cured, after about 4 days, an acidification treatment is essential (6.4.3).

Acid-resistant and alkali-resistant floors Floors exposed to alkali or alkaline solutions, and to acids, shall be provided with acid-resistant bricks or tiles, which shall be laid in synthetic-resin-based mortar on the selected membrane.

Acid-resistant, alkali-resistant and solvent-resistant floors Thermoplastic materials, if resistant against the specified solvents, may be used. Generally a mortar based on polyester, vinyl-ester or epoxy resin, or a mortar of the same base material as used for laying the bricks or tiles, shall be applied as the membrane.

Floors for mildly to moderately aggressive conditions For exposure to mildly aggressive conditions or for temporary service, two methods of protection are recommended: - a layer of bricks or tiles which are embedded in a hydraulic mortar and joined with a

synthetic-resin-based mortar, or - a jointless floor based on synthetic resin. NOTE: Laboratory floors should be included as well.

Jointless systems shall be continuous, liquid-tight and resistant to the chemicals to which they may become exposed.

The floors shall have a slope of at least 1:50 for the drainage of rain water and spillage water, which can be best obtained by applying a concrete fill to the sub-floor.

Figure 4-1: Typical construction of flooring

(zero to moderatechemical-resistance)

Chemical resistantNormal flooringChemical resistant tiles (thickness depending on temperature load)

Bedding material

Primer and/or membrane

Reinforced concrete

5 - 8 mm

Standard drawings S 19.050 (Figure 4-1) and S 19.055 show respectively the construction of a chemical-resistant floor and drains for the discharge of rain water and/or spillage water.

4.3.2 Synthetic-resin-based systems

For exposure to mildly aggressive conditions or for temporary services, the use of jointless floors based on synthetic resin should be considered.

The floors should be provided with a non-slip surface layer, especially where frequent access will be required. Surfaces can be made slip proof by scattering sand, powdered quartz or silicon carbide (e.g. carborundum) on the wet surface immediately after placement.

The following types of floors are commonly used: Trowelling floor

The trowelling floor should be applied in one layer with a thickness varying between 5 mm and 10 mm. The trowelling compound has a high content of filler material. The ratio of binder to filler material is about 1 : 7.5 by weight. An optimum density of the trowelling layer can be obtained by grading the filler material. Trowelling compounds have high compressive strength, excellent adhesion to a wide range of materials and good resistance against corrosive agents.

Self-levelling floor The self-levelling floor should be applied in one layer with a thickness varying between 2 mm and 4 mm. This type of floor has good chemical resistance but a low mechanical strength. By adding filling materials in the ratio of binder to filling material of 1 : 2.5 by weight (but without adding solvents) a sufficiently self-levelling system can be obtained.

4.3.3 Glass-or synthetic fibre-reinforced synthetic-resin based systems

For less severe chemical conditions, these systems may be considered as a possible substitute for brickwork or tiling.

These systems shall not be used in areas where frequent maintenance is executed (dropping of tools, etc.) and/or only in areas with low mechanical loads.

The minimum thickness of such a system should be at least 4 mm.

4.3.4 Resin-based paint systems

Resin-based paint systems on an epoxy or polyurethane etc. basis, may be applied where aggressive products are intermittently present, e.g. in trenches, concrete constructions in plants, chimneys, and on dry or wet floors where chemicals may be spilled.

Epoxy paint systems shall not be used for protection against continuous chemical attack, not even for mildly aggressive conditions, nor in areas where frequent maintenance is executed on equipment, nor in areas where mechanical loads can be expected.

If the concrete will be exposed to brackish or lightly contaminated water, a phenol-free bitumen coating may be used. The dry film thickness shall be at least 400 m.

4.4 CHEMICAL-RESISTANT BRICK LINING SYSTEMS

4.4.1 General Chemical-resistant brick linings consist of bricks or tiles laid in mortar. They are part of a multi-layer system which generally consists of: concrete, providing rigidity and strength; an impervious membrane, to prevent the corrosive medium from reaching the concrete; one or more layers of chemical-resistant bricks or tiles laid in a chemical-resistant

mortar, mainly as a protective layer for the membrane (i.e. thermal loads and mechanical impact).

The chemical-resistant brick lining, including the membrane, primarily protects the concrete. It is necessary for each layer of brick, including every joint, to be bonded to the next layer in order to form a composite construction with the concrete and the membrane.

Great care shall be taken to avoid anything that might lead to failure of the bond between adjacent layers of brick or the complete lining and the concrete structure. Although bricks, tiles and mortars are to some extent permeable, the action of the corrosive medium within the porous material is hampered by the corrosion products formed within the pores, thus preventing further attack.

A chemical-resistant brick lining is liable to crack formation due to the brittleness of the ceramic materials and the bonding strength between the cement and bricks or tiles. The difference in thermal expansion between the lining and the concrete substrate should therefore be taken into account. Cracks in the brick lining will allow penetration of the corrosive agents/fluids through the lining, which will result in damage to the concrete if the membrane fails.

Tiles are generally applied to surfaces which are readily accessible and to floors which are not heavily loaded, otherwise bricks should be used.

Various types of mortar can be used for laying bricks or tiles, a summary of which is given in (6.4).

4.4.2 Membranes

The chemical resistance of the various membrane materials is given in (2) and PTS 30.10.02.13

A summary of the main inspection requirements which are to be met by the various membrane materials is given in Table 10-1. The materials used for membranes on concrete structures are dealt with in Appendix 1, and the requirements for installation are given in (6.3).

Membranes or protective intermediate layers between chemical-resistant brickwork and a reinforced concrete structure are of prime importance for the operation and service life of a brick lining.

Membranes shall be continuous, vapour-tight and, in order to prevent damage to the joints in the chemical-resistant layer, sufficiently flexible to allow for expansion and contraction induced by structural movements.

4.4.3 Expansion joints

Expansion joints are the weakest parts in chemical-resistant brickwork and tiling, and should therefore be installed outside the zones of chemical attack.

When this cannot be avoided, they should be located in areas where there is the least possible chance of aggressive liquids permeating them, e.g. not at the lowest point of the drainage slope.

Figure 4-2: Expansion joint for (limited) unilateral movement

Chemical/temperature resistantelastic sealing compoundChemical-resistant bricks or tilesBedding materialMembrane

Plastic foil to be glued to theconcrete

Concrete fill to obtain slope

Reinforced concretePlastic joint filler

Backing material

Standard Drawings S 19.051 (Figure 4-2) and S 19.052 (for (limited) multidirectional movement) show typical details of sealing expansion joints.

Joints sealed with chemical/temperature resistant elastic sealing compound This type of joint is the most suitable construction at locations subject to severe chemical attack.

At the expansion joint, the reinforced concrete shall have a 10 mm wide gap filled with a plastic joint filler.

The concrete fill applied on top of the concrete provides the required slope for drainage and shall have a gap at the same location and of the same width as the joint. The joint shall be sealed with a plastic foil, adhesive-bonded to the concrete, and the gap shall be filled with a chemical/temperature resistant elastic sealing compound.

Joints filled with asphaltic bitumen The construction shall be similar to that described above. However, in this case the joint is completely filled with Shell Cariphalte JS or equivalent. NOTE: Shell Cariphalte is a product of Synthasco Bouwchemie B.V., NL (1.1).

4.5 TRENCHES

Chemical-resistant trenches can be subdivided as follows: Trenches without continuous chemical attack Drains, sewer systems, pits, etc., are often attacked by chemical products present in the

waste water. For such conditions a trowelling compound (4.3.2) or an epoxy coating system (4.3.4) should be applied.

Acid-resistant trenches Trenches for acid service only, and not exposed to traces of alkali, steam or hot water,

shall be provided with a layer of acid-resistant bricks or tiles. They shall be laid in silicate mortar on the membrane, as described for acid resistant floors (4.3.1).

Acid- resistant and alkali-resistant trenches Trenches exposed to alkali, alkaline solutions or acids shall be provided with acid-resistant bricks or tiles, which shall be laid in synthetic resin-based mortar on the membrane, as described for acid- and alkali-resistant floors (4.3.1).

Acid-resistant, alkali-resistant and solvent-resistant trenches For trenches designed for transport of corrosive effluents containing petrochemical solvents, the recommendations as laid down in (4.3.1) shall be followed.

Trenches exposed to chemical attack will normally be constructed of reinforced concrete, and shall be provided with a lining suitable for the respective chemical and thermal conditions.

The trench bottom should have a slope of 1: 50 for drainage. A lesser slope may be considered for long trenches, but shall not be less than 1: 200. The slope may be obtained by the application of a concrete fill on the trench bottom.

The trench shall be wide enough to ensure that the acid-resistant tile or brick lining can be properly laid, i.e. preferably based on their standard dimensions to avoid unnecessary cutting and material loss. The side walls shall be vertical.

When a trench is constructed in an acid-resistant floor, the membrane of both the floor and the trench shall be continuous.

Figure 4-3: Typical construction of trenches

concrete fill to obtain slope

membrane

chemical resistant bricks or tiles5 - 8 mm bedding material

concrete fill to obtain slopereinforced concrete

50

grating

Typical construction details of trenches are given in Standard Drawings S 19,060 (Figure 4-3), S 19.062 and S 19.065. Preferably trenches shall be covered with a chemical resistant type grating and suitable for carrying mechanical loads, e.g. for persons and/or transport equipment.

4.6 NEUTRALISATION PITS Deep pits should be lined with acid-resistant bricks instead of tiles because of the mechanical impacts due to filling of the compartments or removal of the fill and scraping for cleaning during maintenance.

Acid-resistant bricks shall also be used for: Partition walls

Lining of compartments to be filled with chalk or lime, because tiles may be damaged when the compartments are scraped out

The contents of these compartments will generally be acidic or neutral. The acid-resistant bricks shall therefore be laid in silicate mortar on the selected membrane (6.4.3).

For selection of the membrane, see (3.1).

Other compartments

The contents of compartments are normally alkaline but may become locally or completely acidic, depending on the nature of the liquid to be neutralised.

The acid-resistant bricks shall therefore be laid in synthetic resin-based mortar on the selected membrane (6.4.4).

If the contents of a trench leading to a neutralisation pit are expected to occasionally become alkaline, the bricks in the neutralisation pit (including the compartments to be filled with chalk) shall be laid in synthetic-resin-based mortar (6.4.4). NOTE: If the contents of a neutralisation pit may become contaminated with petrochemical

solvents, the directions given in (4.3) shall be followed.

Trenches discharging acidic liquids need a certain slope for drainage, therefore neutralisation pits should be built as near as possible to the location where the acid is discharged, to keep the depth of the trench to a minimum.

Neutralisation pits should normally be constructed of reinforced concrete (4.8). They shall have vertical walls and may consist of a number of compartments.

For neutralising acidic effluents, neutralisation pits may be filled with chalk (calcium carbonate), lime (calcium hydroxide), a lime slurry or a solution of sodium hydroxide.

The contents of chalk-filled compartments into which an acidic liquid flows will generally be acidic or neutral.

The contents of compartments filled with lime, sodium hydroxide solution or a lime slurry will normally be alkaline, but may become locally or completely acidic depending on the liquid to be neutralised.

4.7 DRAINAGE AND PRIMARY TREATMENT FACILITIES

The main building material for drainage and effluent treatment facilities, e.g. basins, tanks, trenches, sumps, and bays, is concrete. Despite considerable advances in the technology of constructing high-quality concrete, it may still be necessary to provide suitable protection against the wide range of chemical conditions in these facilities.

Waste water to be treated may contain solid and/or liquid organic or inorganic substances of all kinds, which will mainly attack the cement stone in the concrete structures. Refer also to PTS 34.14.20.31

Depending on the chemical loads, linings shall be selected in accordance with (2).

4.8 CONCRETE VESSELS

During initial design, attention shall be paid to possible alternative construction materials, e.g. the use of steel for neutralisation pits and sulphur-containing vessels, or the use of proprietary systems as false form work, etc.

Such proprietary plastics systems, e.g. Bekaplast from Steuler Industriewerke GmbH, Kera from Keram-Chemie GmbH, (1.1), available in both thermoplastic and thermosetting materials, may be used if the Manufacturer/Supplier can provide evidence of the long term reliability and economic benefit of such systems to the Principal.

Design and acceptance of concrete vessels shall meet the requirements of PTS 34.19.20.31 For underground sulphur storage tanks for Sulphur Recovery Units, reference is made to PTS 64.24.32.11

Tongue and groove materials are often used in larger constructions, to obtain improved stability and a labyrinth-like joint lengthening. Concrete vessels of great length, which are also exposed to temperature variations and which cannot be constructed with curved walls or with pillar piers, should be designed with dowel-brick constructions, i.e. a dovetail groove in the concrete in which similar shaped bricks are placed, generally at 1.5 m to 2 m intervals.

The concrete vessel shall be water tested to ensure liquid-tightness before construction of the lining, and subsequently dried in accordance with (6.1) prior to instllation or preparations for installation of any chemical-resistant lining.

The lining shall be selected in accordance with the previous sections of this PTS, according to the corrosiveness of the fluid to be contained.

4.9 PROTECTION SYSTEMS FOR MISCELLANEOUS CONSTRUCTIONS

4.9.1 Pump foundations For chemical-resistant protection of reinforced concrete pump foundations, typical details are shown on Standard Drawing S 19.071.

The membrane of the floor and that of the pump foundation shall be continuous. The membrane shall also be continuous under the pump base.

Special care shall be taken where bolts penetrate the membrane construction, i.e. that no aggressive medium can penetrate along bolts to behind the membrane and/or that no sharp edges of the pump-base or ceramic materials can damage the membrane.

The sides and top of the pump foundation shall be protected by the same lining as the floor on which it is placed.

Acid-resistant bricks or tiles shall be applied to the pump foundation membrane, as described for chemical-resistant floors in (4.3).

For pump foundations exposed to petrochemical solvents, the directions given in (4.3) shall be followed.

If the floor is provided with a trowelling compound, the pump foundations shall have the sides and top protected with the same material and construction.

On the top of the foundation the trowelling compound shall have a liquid-tight joint with the grouting of the pump.

If the floor is painted (4.3.4), the whole pump foundation shall be treated with the same paint system.

4.9.4 Other concrete structures

Protection of concrete shall not be limited to floors, trenches, pits and pump foundations. Parts such as concrete columns, beams, table tops, pump rooms, chimneys, foundations, etc. may also be liable to chemical attack and need therefore a protective lining system at least up to the level where attack is anticipated.

Special attention shall be given to unprotected locations, but where frequent spillage of chemicals can occur, e.g. during loading and discharging of tanks, containers, etc.

Concrete columns, beams, table tops, pump rooms, chimneys, foundations, etc. liable to chemical attack may have to be provided with a lining system.

Generally, the application of an epoxy coating system (4.3.3 or 4.3.4) is sufficient. For underground concrete constructions a suitable flexible rubber/bitumen emulsion coating should be used (4.3.3).

Other areas prone to damage lie near or underneath steam-trap outlets. Although such damage is generally not caused by some sort of chemical attack, the hot steam can cause considerable damage. If outlets are not directed to special collectors or drained into gutters, a typical solution is shown below in Figure 4-4.

Figure 4-4: Typical solution for steam trap outlet (i.e. for non-contaminated steam only!)

Approx.100

Stream trap outlets

Concrete slab

Soil

Infill of coarse shingle

Cast-in concrete tube orequivalentApprox.

600

5. HANDLING AND STORAGE OF LINING MATERIALS Bricks and tiles shall be carefully handled, unloaded and stacked by hand or by using a pair of brick tongs. They shall be stored and protected against weathering conditions, particularly exposure to direct sunlight or frost.

The individual constituents of mortars shall be stored and used in accordance with the Manufacturer's instructions. The shelf life of the materials indicated by the Manufacturer shall be carefully observed and they shall be stored and handled on a basis of first-in/first-out. Materials which have been stored for a period longer than six months shall be subjected to new quality control tests and a test report shall be required and issued before using them.

Hydraulic cements stored longer than three months shall have their suitability checked by determination of the setting time.

Cements of different brands shall not be mixed; labels indicating the name, quality and quantity of the contents shall not be removed.

In cold climates materials may freeze and must be defrosted before use by being stored in a warm place.

Storage and handling of other chemical-resistant materials and resin-based products shall be done in strict compliance with all regulations and safety precautions issued by the Manufacturer/Supplier. Refer also to section 7.

6. LINING INSTALLATION

6.1 SURFACE PREPARATION FOR CONCRETE SURFACES

Prior to the application of a membrane or a coat of primer, the concrete shall be at least 28 days old and the moisture content of the concrete surface (up to approximately 15 mm deep) shall not exceed 4% by volume.

The moisture content of the substrate shall be checked regularly during installation of the lining. Measuring equipment, which shall be calibrated, and the method of establishing moisture content shall be approved by the Principal.

Prior to the application of any lining system, the concrete surface shall be prepared to avoid air inclusions and to ensure sound attachment of the lining. The concrete substrate shall be freed of cement skin, loose sand, dust, laminate, oil, grease or other contaminants by means of non-metallic abrasive blasting.

Subsequently the concrete structure shall be inspected for cracks and other surface defects. The structure shall be free of cracks wider than 0.30 mm and surface defects (for instance fins, air holes, honeycombs, etc.). All such cracks and defects shall be repaired in consultation with the Principal. In liquid retaining structures, cracks wider than 0.20 mm shall be repaired by synthetic resin injection.

Small defects, up to a depth of approximately 50 mm, shall be sealed with a quartz-filled epoxy mortar (composition 75% by volume quartz and 25% by volume resin). Larger repairs shall be carried out with non-shrink cement-based mortars.

The surface of the repaired defects shall be smooth and flush with the surrounding surfaces. The final surfaces shall be smooth and even without any sharp edges, burrs, etc. (radius > 5 mm). Walls and floor shall not bulge inwards, as this could cause the brick lining to break away as a result of uneven expansion during operation.

Concrete which has already been damaged by chemical products shall be neutralised or if necessary removed to sound concrete and renewed. This repair shall be carried out in consultation with the Principal.

For already used or dirty concrete floors, the preparation shall be carried out by first completely wetting with water, then etching with a diluted hydrochloric acid (5 - 10% by weight), then neutralising with a dilute ammonia solution (approx. 15% by weight), and then washing the floor with an excess of water. If the concrete floor contains cracks, an acid treatment shall not be performed because it may cause corrosion of the steel reinforcement. Alternatively the surface may be prepared by means of grinding the concrete until a sound and clean surface has been reached.

If required, the concrete surface shall be made level by an appropriate cement/sand mortar 1 : 3 (by volume). Slopes are made by applying a concrete fill to the sub-floor with a minimum thickness of 25 mm or with a suitable special designed polymer floor-mortar. Before these layers are applied the concrete shall be pre-treated, e.g. with an appropriate cement-rich mortar slurry.

6.2 EXPANSION JOINTS

The expansion joint provided in the reinforced concrete structure (4.4.3) shall be filled with semi-rigid polyurethane foam, insulation cord, or other appropriate material. Concrete fill shall be applied on top of the concrete to provide the required slope for drainage and shall have a gap at the same location, and of the same width, as the joint.

The joint shall be sealed with a plastic, e.g. polyisobutylene foil 3 mm thick, or other suitable material.

The foil shall be installed as shown in Standard Drawing S 19.051, and adhesive-bonded to the substrate; the adhesive should be of a bituminous or rubber type. The membrane and a layer of bricks or tiles shall then be applied, keeping the joint open.

The joint shall then be cleaned (up to the joints backing material) and filled with a chemical/ temperature resistant elastic sealing compound.

6.3 MEMBRANES

Membranes, other than (6.3.1), shall be clean and free of dust, oil, grease or other contaminants.

6.3.1 Asphaltic bitumen membranes

Membranes of asphaltic bitumen shall be applied to primed surfaces only, for which purpose the Suppliers recommendations shall be followed.

The surface of the membrane shall be sanded for good adhesion of the subsequent mortar layer, e.g. by brushing with a solution of bitumen and spreading quartz sand (0.7 - 1.2 mm grain size) onto the bitumen coating whilst it is still tacky.

The asphaltic bitumen shall be spread by 'squeegees' or brush until it is smooth, even and free of irregularities. For pump foundations, the membrane shall be applied before the pump base plate is installed. The surface of the membrane shall be sanded as mentioned above.

6.3.2 Thermoplastic membranes

Before the membrane is adhesive bonded to the concrete surface, the latter shall be prepared in accordance with the Manufacturer's instructions. A primer shall be applied to the concrete surface if required.

The membrane shall not be applied at substrate or ambient temperatures below 5 C.

6.3.3 Thermosetting membranes

The cement skin of the concrete surface shall be removed by means of grit blasting and the surface shall be freed of grit and loose debris.

The cleaned/rough surface shall be given an epoxy-resin-based primer, and then within 24 hours the epoxy resin and the glass fibre reinforcement (if any) shall be applied to the specified thickness.

An epoxy membrane shall not be applied during rain if the surface is not suitably protected, or at substrate/atmospheric temperatures below 10 C.

6.4 MORTARS

6.4.1 General

The mortar shall be mixed in accordance with the Manufacturer's instructions. The tools and mixer shall be clean and dry. Specific constituents to be used for mixing a certain type of mortar shall never be mixed with constituents for other type of mortars.

Mortars shall not be applied under freezing conditions.

As the setting time of most resin-based mortars is influenced by atmospheric conditions, special attention should be paid to the Manufacturer's instructions.

Prior to the application of mortars directly to a concrete and/or brickwork substrate, the surfaces shall be made liquid-tight with an adequate primer. Additional sanding may be required to improve adhesion of subsequent mortar layers.

6.4.2 Mortars based on hydraulic cements

Layers of these mortars, applied to provide slopes, shall be kept wet during curing (for about one week) to obtain optimum strength and to avoid hairline cracks.

Hydraulic cement supplied in paper bags should be used within 8 hours of opening the bag.

The mortar used as bedding mortar should normally have a cement/sand ratio of 1 : 3 by volume.

6.4.3 Mortars based on silicate cement

The mortar supplied in two components, a liquid and a powder, shall be thoroughly mixed and used immediately.

The mixture has a certain pot-life, i.e. time during which it can be readily used. To avoid using mortar which has already started to cure, only a limited quantity should be mixed at a time.

On completion of the lining, "acidulation" of the brick lining is required as the alkali hydroxide formed during curing is detrimental to the joint and would eventually destroy it.

Four days after application, the brickwork shall be washed with dilute acid, e.g. a 10% by weight solution of hydrochloric acid.

6.4.4 Mortars based on phenol-furfuraldehyde resin The mortar supplied in two components, a liquid and a powder, shall be thoroughly mixed and used immediately.

The mixture has a certain pot-life, i.e. time during which it can be readily used. To avoid using mortar which has already started to cure, only a limited quantity should be mixed at a time.

The rate of setting and curing of the mortar is influenced by temperature, and mixing components shall comply with these ambient conditions. In general at 15 - 20 C the mortar starts to set in about four hours and cures in 1 - 2 hours. This also depends on the catalyst used, e.g. at a lower temperature the mortar starts to set and cure at a lower rate too. Generally, for optimum chemical resistance, curing should be done for one week at the above temperatures.

If the temperature falls below 15 C, acceleration of the curing by heating, e.g. 16 hours minimum at 80 C, may be considered. However, care should be taken to ensure that the temperature does not exceed 80 C, as the difference in expansion between tile, substrate and the top surface may adversely affect adhesion.

Contact with water and/or water vapour during curing shall be avoided. The heating should therefore be carried out by means of electric heaters.

It is essential that during the curing the mortar does not come into contact with free alkali, since this would tend to neutralise the acid catalyst. Consequently the concrete floor shall be primed with two coats of a suitable primer if these mortars are used as a membrane. The primer shall be in accordance with the Manufacturer's recommendations.

6.4.5 Mortars based on furane resin

Furane-resin-based mortar cannot be applied directly to concrete surfaces. When a membrane of this mortar has to be applied, the concrete shall be pre-treated with a primer in accordance with the Manufacturer's instructions.

The precautions which have to be taken as regards pot-life and mixing are identical with those for phenol-based mortars. The mortar cures at 15 C - 20 C in about 3 days. Optimum chemical resistance can be obtained by heating at 80 C for at least 16 hours after application.

For application of these mortars the same rules apply as for the application of cements based on phenol-furfuraldehyde resin (6.4.4).

6.4.6 Mortars based on polyester resin

The components, in the form of a powder and a liquid resin, shall be mixed immediately before use. They are self-curing at 15 C to 20 C; a complete cure at this temperature can

be obtained in 24 hours. For optimum chemical resistance a longer curing period is recommended. The curing time and pot-life are affected by temperature.

Contact with water or water vapour shall be avoided during curing.

6.4.7 Mortars based on epoxy resin

These mortars are generally supplied as a paste of putty-like consistency, together with a liquid curing agent.

After the two components have been mixed the mortar cures within one hour at temperatures of 10 C to 30 C. The curing time is affected by temperature. The curing agent generally used is a cold-curing type, which limits the maximum operating temperature but facilitates processing. In tropical conditions a hot-curing type is recommended due to its prolonged pot life.

Contact with water or water vapour shall be avoided during curing.

Epoxy resin-based mortars have very good chemical resistance. If a filler such as graphite is added, resistance to hydrofluoric acid is also obtained.

6.5 BRICKS AND TILES

Bricks and tiles shall be clean and dry and should have a temperature of at least 15 C on application.

If a brick lining has to be applied in winter, provisions shall be taken to protect the area from cold, rain, snow, etc.

For narrow joints the bricks or tiles should fit correctly, which requires that they shall be selected at site with regard to their squareness and dimensions.

Vertical parts should be lined before horizontal parts. In that way the vertically placed lining is held in place by the bottom layers, which eases repair of the generally higher (mechanical) loaded floor tiles.

When a membrane is present the bottom shall be protected first with a brick layer. However in such cases it is recommended to place one shell layer first and then the bottom layer inside of it. In a multi-layer application, at least the top layer of the bottom lining shall be placed as described.

Acid-resistant bricks or tiles shall be applied to pump foundations before the bricks or tiles are laid on the adjoining floors.

6.5.1 Jointing bricks and tiles Bricks and tiles shall be fully laid in mortar (bed and cross joints), except when cross joints between bricks or tiles will have a different kind of mortar, e.g. with enhanced resistance against the envisaged chemical loads. Air inclusions shall avoided, since they may get filled with aggressive chemicals, or may exert uncontrolled high pressures at elevated temperatures.

The bed joint between the bricks or tiles and the membrane shall have a thickness of about 5 mm. The rough surfaces to be embedded shall have no edges (i.e. from split tiles or hand-cut bricks) larger than 3 mm, to assure that sufficient mortar thickness remains present between the bricks or tiles and the membrane.

The width of cross joints between bricks or tiles shall be between 3 and 5 mm. However, the width shall be between 5 and 8 mm for certain hot pour jointing materials or if the joints require sealing. When re-jointing may be required after a period of service, the joint shall be made at least 5 mm wide.

The width of the cross joints shall be consistent over the full depth of the joint and the filling free of cavities and/or air inclusions.

6.6 JOINTLESS (FLOOR) SYSTEMS

6.6.1 General Concrete floors to be provided with jointless flooring shall have an even, smooth surface, prepared in accordance with (6.1) and shall be at least 6 weeks old prior to application of the flooring.

To obtain good adhesion between the flooring and the concrete, the latter shall be sealed with one or more coats of an unfilled solvent-free resin primer. In general the unfilled liquid component of the flooring compound is used as a primer.

6.6.2 Application of the trowelling floor

The floor shall be applied in accordance with the Manufacturer's instructions. The trowelling floor shall be applied "wet in wet" until the specified thickness has been obtained.

The surface of the trowelling layer may be compacted by the use of mechanical equipment.

6.6.3 Application of the self-levelling floor

The floor shall be applied in accordance with the Manufacturer's instructions.

The application can be carried out by casting or spraying to the specified thickness.

In order to make the floor slip-proof (if required), sand or powdered quartz or carborundum shall be scattered on at the moment of gelling of the flooring, so that it will not sink into the material.

6.6.4 Application of a glass fibre reinforced synthetic resin

After preparation of the concrete surface, an epoxy primer consisting of a mixture of resin and curing agent shall be sprayed or brushed onto the concrete.

Subsequently various layers of glass fibre or synthetic fibre reinforcement, after being impregnated with synthetic resin, shall be applied until the specified thickness has been obtained.

Glass fibres or synthetic fibres shall be chosen in accordance with the chemical load and at least the top coat shall be UV-resistant in case of exposure to the environment.

6.6.5 Application of a synthetic-resin-based paint system

Concrete surfaces should be commercially blasted to remove the cement film and be made dust free (6.1.1).

The surface shall be levelled (if required) using an epoxy filling system.

The epoxy paint shall be applied to a clean and dry concrete surface by means of a brush, roller or spraying equipment.

The system shall consist of a primer and two or more coats of high-build paint, applied to a total dry film thickness of at least 400 m. The application of the paint to the concrete shall be in accordance with the Manufacturer's instructions.

7. HEALTH, SAFETY AND ENVIRONMENTAL (HSE) ASPECTS Local HSE regulations shall be met.

Chemical-resistant lining materials are chemical composites and the mixtures can contain or form hazardous chemical components. These can occur both in freshly produced mixtures as well as in use, and during removal of aged materials.

All safety precautions and/or measures for the use and handling of these materials, including recommendations, e.g. for ventilation requirements when used in confined areas and disposal requirements of surplus materials, shall be provided by the Manufacturer/Supplier.

Material safety data sheets shall be supplied for each component of the lining system by the Manufacturer and the Applicator shall retain copies and appropriate safety bulletins at site.

The Applicator shall strictly obey the regulations and all safety measures required, which are mandatory for any worker seeking to access the equipment to start work. The Principal shall be informed about all personnel requiring access to the work, such as labour, QA/QC personnel and supervisors.

All necessary arrangements and safety precautions, including those of the Principal, should be fixed in entry certificates, with a limited period of validity.

Skin contact with chemical components should be prevented by using rubber gloves and barrier creams, and any accidentally contaminated skin areas should be thoroughly washed with soap and water or, if necessary, the Manufacturer's special instructions shall be followed. Subsequent rubbing of lanolin-containing creams into the skin may be beneficial.

Skin contact with synthetic-resin-based materials shall be avoided. They may also produce stains on clothing. Applicators shall therefore observe strict personal hygiene and take care when handling these materials in the uncured liquid state.

8. QUALITY CONTROL The installation of chemical-resistant linings on concrete constructions is critical for the reliability of these structures.

The required properties of the chemical-resistant materials and the sampling and testing requirements are specified in Appendix 1.

The application of chemical-resistant linings involves several distinct steps from design to installation. Lack of quality control in any of these steps could lead to complete failure of the lining. It is therefore of vital importance for a quality control procedure to be established for each chemical-resistant lining application, covering all aspects from material selection up to and including final inspection of the installed lining.

This principal procedural aspects of quality control which should be covered as a minimum are as follows:

Base material selection Clearly specified requirements Manufacturing of materials Inspection, testing Design Design requirements to enable a sound lining Material shipment and storage Requirements, inspection, certification Installation/application Requirements, inspection, Applicator's procedure

Qualification of equipment and crew Completed lining Inspection, progression testing Lining repairs Methods, requirements, inspection

The Contractor shall set up an appropriate quality control programme addressing at least all steps described above.

The Contractor shall provide Suppliers and Applicators with sufficiently detailed specifications for each of their specific activities. In particular the demarcation of responsibilities and the smooth hand-over between the parties involved should be duly covered in the quality assurance programme.

Lining details shall be included on drawings. They may also be provided by equipment suppliers. Any conflicting requirements shall be investigated by the Contractor and referred to the Principal for resolution before quoting for the work or proceeding with the lining execution.

The properties and applications shall be tested in accordance with ISO or equivalent standards. All chemical-resistant materials shall be tested by a recognised laboratory, experienced in testing refractory materials.

For the applicable testing standards for ceramic materials, refer to PTS 64.24.32.30, Table 3-1.

9. INSPECTION BEFORE AND AFTER INSTALLATION Before a membrane, is applied the concrete surface should be inspected for cleanliness, moisture content and defects (6.1), e.g.: wiping a dark cloth over the surface will reveal presence of unwanted dust; if water sprinkled on the surface beads or forms droplets, traces of form-release agents

or curing compounds may still be present; if a curing compound has been used its compatibility with the adhesive shall be checked

or else that compound be removed.

The specified slope, if any, shall be checked and approved by the Principal.

Prior to the start of the work, mixing tests of mortars and jointing components, followed by testing of strength properties, shall be executed.

A summary of the main requirements for membranes is given in table 9-1.

Table 9-1: Summary of main requirements for membranes Membrane material Property Test method/criteria Asphaltic bitumen

(3.1.2) Plastics

(3.1.3/3.1.4) Surface condition/ Visual examination

No surface defects. x x

Adhesion Check by careful knocking. No lack of adhesion.

x x

Porosity Visual examination. No porosity. x x

Thickness 1) Physical measurement. x x

Curing No softening after 1 minute rubbing with acetone. x 2)

NOTES: 1. Depending on the type of membrane, thickness may be measured before or after application. Layer thickness meters are unsuitable for use on concrete substrates, so only physical measurements shall be taken after application.

2. Applies only to glass fibre reinforced epoxy-resin-based membranes.

Pull-off tests and holiday testing of plastic membranes shall be done in accordance with PTS 30.48.60.10

During application of the membrane, inspection shall be carried out and due attention should be paid to the following points: sufficient adhesive shall be applied;

the membrane shall be applied without air inclusions or other visible defects; NOTE: In pits or tanks final inspection can be carried out after hydraulic or vacuum testing.

damages as result of installation accidents shall be noted and treated; faults of the seams or of overlapping shall be noted and treated;

bricks and tiles (especially cut tiles!) shall have no sharp edges, burrs, etc. which can damage the membrane (radius > 3 mm).

Brick lining shall not be commenced until the applied membrane has been inspected and accepted by the Principal.

Upon completion the brick lining shall be inspected for the following conditions: general appearance of the brick lining; the specified dimensions of the joint; the execution of the jointing.

Until brick linings are fully cured, they shall be protected against mechanical abuse, welding activities, scaffolding, etc., and detrimental weather effects, for example cold, heat and rain.

10. MAINTENANCE AND REPAIR Chemical-resistant linings shall be regularly inspected for defects. They shall be carefully treated and protected against damage by mechanical loads, impact and inadmissible local chemical and thermal attack (steam, leaking flanges, etc.). NOTE: When a defect is detected, repairs shall be carried out immediately in order to prevent serious attack

of the concrete substrate.

The main defects are spalling of the bricks or tiles, erosion effects, cracks in the lining and degradation of the chemical-resistant lining materials.

Spalling of the brick lining may be due to: inadequate brick quality, e.g. composition, porosity; exposure to exceptional operating conditions, e.g. thermal, chemical or other loads more

severe than those foreseen; local spalling by the impact by a falling object.

Damaged areas or spots shall be opened up to sound material and shall be repaired by replacement with new material, either of the original quality or of another quality, providing the latter is fully compatible with the adjacent original material with respect to physical and chemical properties.

If the effects of erosion or attack by chemicals are slight, the joints can be repaired by means of scraping out to sound material and filling with fresh mortar. If the depth of the scraped-out joint is 75% or more of the thickness of the brick layer, all the cement in the joint shall be removed and replaced. If necessary the bricks shall be re-laid, for which purpose a sufficient number of bricks shall be taken out to restore the brick lining configuration. If cracks in the lining are present, they shall be opened completely to establish the condition of the membrane and/or substrate. Care shall be taken not to extend the damage by removing the affected parts.

Degradation of the lining materials may indicate excessive chemical attack. The chemical conditions causing the degradation shall be established and appropriate countermeasures shall be taken.

If defects other than those described above are found, their cause should be determined and the construction reviewed to avoid further attack of the concrete construction.

11. REFERENCES In this PTS, reference is made to the following publications: NOTE: Unless specifically designated by date, the latest edition of each publication shall be used, together

with any amendments/supplements/revisions thereto.

PETRONAS STANDARDS Index to PTS publications and standard specifications

PTS 00.00.05.05

Index to Standard Drawings PTS 00.00.06.06

Non-metallic materials selection and application PTS 30.10.02.13

Painting and coating of new equipment PTS 30.48.00.31

Rubber-lined process equipment, piping and piping PTS 30.48.60.10

Design and installation of chemical-resistant brick lining for process equipment

PTS 30.48.60.13

Drainage and primary treatment facilities PTS 34.14.20.31

Reinforced concrete foundations and structures PTS 34.19.20.31

Refractory bricks and shapes PTS 44.24.90.31

Refractory materials for sulphur recovery units (Claus & SCOT)

PTS 64.24.32.11

Insulating and dense refractory concrete linings PTS 64.24.32.30

STANDARD DRAWINGS Note: The latest issue dates of standard drawings are

identified in PTS 00.00.06.06

Chemical-resistant brick linings for concrete structures -

Flooring S 19.050

Detail of expansion joint in floors S 19.051

Detail of expansion joint between floor and wall

S 19.052

Drain construction in floors S 19.055

Trench construction with vitrified-clay split tiles and vitrified-clay components

S 19.060

Trench construction with vitrified-clay split tiles and vitrified-clay half-round channels

S 19.062

Open trench construction lined with bricks or tiles

S 19.065

Detail of foundation S 19.071

GERMAN STANDARDS Chemical equipment; building materials for brick-lining, classification, properties, testing

DIN 28062

Issued by: Beuth Verlag GmbH Burggrafenstrae 4-10, 1000 Berlin 30, Germany

INTERNATIONAL STANDARDS Refractory products; Measurement of dimensions and external defects of refractory bricks:

Part 1: Dimensions and conformity to drawings

ISO 12678-1

Part 2: Corner and edge defects and other surface imperfections

ISO 12678-2

Issued by: International Organisation for Standardization 1, Rue du Varemb CH-1211 Geneva Switzerland Copies can also be obtained from national standards organizations

12. BIBLIOGRAPHY NOTE: The documents listed in this Bibliography are for information only and do not form an integral part of

this PTS.

Linings over concrete for immersion services NACE RP0892

Coatings for concrete surfaces in non-immersion and atmospheric services

NACE RP0591

Issued by: NACE International 1440 South Creek Drive Houston, Texas 77084 USA

Handbook of acid-proof construction ISBN-0-89573-370-6

APPENDIX 1 SPECIFICATION FOR MATERIALS, SAMPLING, TESTING AND PACKAGING

1. GENERAL This specification provides the requirements for the physical properties of chemical-resistant lining materials for application in both process equipment and concrete structures, including the testing and acceptance criteria for these materials.

Unless otherwise specified, acid-resisting materials shall be selected in accordance with DIN 28062. The properties of ceramic materials shall be tested in accordance with the standards shown in Table 3-1 of PTS 64.24.32.30 They shall meet the requirements of the purchasing documents.

Sampling and dimensional control shall be done in combination with PTS 44.24.90.31, appendix 2.

For (acid-resistant) refractory bricks and shapes reference is made to PTS 44.24.90.31

2. SPECIFICATIONS FOR MATERIALS

2.1 MEMBRANES

Membranes shall be continuous, vapour-tight and resistant to the chemicals to which they may become exposed.

It is stressed that the optimum properties of the membranes are achieved only when installed in accordance with the appropriate installation specifications.

2.1.1 Asphaltic bitumen Asphaltic bitumen membranes not subject to mechanical loads shall be made of blown bitumen, i.e. a softening point 115 C and a penetration depth of 0.5 mm at 25 C, without fillers and consisting of a 6 mm dry film thickness layer.

Asphaltic bitumen membranes, designed to sustain mechanical loads in service and consisting of a 20 mm dry film thickness layer, shall be prepared as follows:

A filler shall be made by mixing 80 parts by weight of river sand (passing a sieve opening of 2 mm or finer) and 20 parts by weight of fine quartz powder, of which at least 75% should pass a sieve opening of 75 m or finer.

12 to 13 parts by weight of asphaltic bitumen, i.e. penetration range 2 - 3 mm, shall be added to 100 parts of filler, and the components shall then be heated to 200 C and properly mixed.

If required a primer shall be provided under a membrane of asphaltic bitumen. NOTE: Belgian Shell or Synthasco Bouwchemie B.V., NL could be contacted for availability and/or equivalent

bituminous materials.

2.1.2 Thermoplastics

Thermoplastic membranes are principally based on polyisobutylene. They may be used for membranes on concrete surfaces, depending on the required chemical and temperature resistance.

The polyisobutylene sheet shall meet the following requirements: colour : black thickness : minimum 1.5 mm density : minimum 1.4 kg/dm3 tensile strength : minimum 2 N/mm2 elongation : minimum 300 %

The minimum required thickness is 5 mm.

The maximum allowable operating temperature is 70 C.

If the use of proprietary systems is considered, approval from the Principal shall be obtained.

2.1.3 Thermosetting materials

Resins based on epoxy, polyurethane, furane, phenol, polyester and acrylic may be used for membranes on concrete surfaces, depending on the required chemical and temperature resistance.

Properties are dependent on the type of resin, type of filler or pigment, curing agent, curing method and the possible use of fibrous reinforcements (e.g. glass fibre). The Manufacturer shall state the composition.

The average thickness of this membrane should be 5 mm, with a minimum of 3 mm.

The in-service temperature resistance of glass fibre reinforced synthetic-resin systems ranges from -40 C up to +140 C.

No additional fillers or pigments etc. shall be used in membranes, except where a resin-based membrane is used as a final (concrete) surface finish.

2.2 CEMENTS AND MORTARS

2.2.1 Hydraulic cement

Hydraulic cements, based on Portland clinkers, blast furnace slag or high aluminium oxide containing raw materials, shall be in accordance with PTS 34.19.20.31 or internationally accepted standards.

2.2.2 Silicate based cements

Sodium silicate, potassium silicate and silica cements shall be in accordance with DIN 28062 type 2.2.

Silicate-based mortars are two component systems. They consist of a sodium or potassium silicate solution mixed with inert fillers, e.g. quartz flour. The mortar cures as silica is deposited from the alkali silicate solutions, a process which is accelerated by the presence of a catalyst, e.g. salts of fluorosilicic acid or dimethyl-formamide.

2.2.3 Synthetic resin based cements

These cements shall be in accordance with DIN 28062 type 2.3.

Mortars based on

Phenol-furfuraldehyde resin

These mortars consist of phenol-formaldehyde resin and furane derivatives with an inert filler. They are supplied as two components, a liquid resin solution and an inert powder (both of which also contain part of the reactive agent), which shall be thoroughly mixed together.

Modified phenolic resin-based mortars have been developed to cover a wider range than pure phenol-formaldehyde resin or furane resin mortars. If resistance to hydrofluoric acid is required, graphite, not sand or barytes, shall be used as a filler.

The time lapse between application and curing shall be kept to an absolute minimum. In order to give the mortar its full chemical resistance (in particular to caustic alkalis), the cement requires a heat treatment at 80 C for 24 hours after it has fully cured.

The operating temperature limit of these mortars is 140 C.

Furane resin

They are supplied as two components (a powder and a liquid) which give the mortar excellent adhesive qualities when mixed correctly. The liquid cures to a hard solid resin

on addition of suitable catalysts. Furane based resins shall contain less than 1% of free furfural.

The operating temperature limit of furane resin cement is approximately 140 C.

Polyester resin

Mortars based on (unsaturated) polyester resin are supplied in two or more components, i.e. liquid resin, catalyst, accelerator, filler, etc., which shall be mixed together.

The addition of inert fillers such as graphite to the mortar extends its resistance even to hydrofluoric acid and its resistance against alkalis increases.

The operating temperature limit of polyester resin based mortars is 120 C.

Epoxy resin

Mortars based on epoxy resin are supplied in two or more components.

Various formulations will have different properties, according to the different curing agents used.

The temperature limit of epoxy resin based mortars is 110 C.

2.2.4 Epoxy paint systems Epoxy paint systems are applied where aggressive products are occasionally present, e.g. on concrete constructions in plants, chimneys, and on dry or wet floors, where chemicals may be spilled.

The properties are dependent on the type of resin, type of filler or pigment, curing agent, curing method and the possible use of fibrous reinforcements (e.g. glass fibre). The Manufacturer shall state the composition and the Principal shall be consulted .

2.3 CERAMIC AND CARBONACEOUS MATERIALS

Because of the special nature of chemical resistant linings, many manufacturers have specialised in the development and engineering of dedicated ceramic and carbonaceous products and shapes in order to suit the required application. These developments are generally detailed in special catalogues, which contain a wide variety of bricks and tiles and shapes, which may vary per manufacturer, and can be consulted.

If so required in areas with frequent access of personnel, ceramic materials shall be provided with anti-slip arrangements, e.g. ridges or equivalent, but in such manner that washing away of liquids shall never be obstructed.

2.3.1 Acid resistant bricks and tiles The main constituents of acid-resistant bricks and tiles are SiO2 and Al2O3.

Their properties are determined by: chemical composition (i.e. SiO2 and Al2O3 and addition of special components);

NOTE: Usually the Al2O3 content is between 15 and 30% by weight, but if kept below 10% by weight an improved chemical resistance will be achieved. Conversely, the chemical resistance will decrease at an Al2O3 content higher than 30% by weight .

type of mineral constituents (i.e. crystalline and glassy phase); structure and distribution of the grains; porosity; firing/bonding temperatures.

Acid-resistant bricks and tiles (including 'Glover' bricks) shall be in accordance with DIN 28062 type 1.1.2. For convenience a summary is given in section 5 of this appendix.

Unless otherwise specified acid-resistant bricks and tiles with an apparent porosity of 5% maximum, which are resistant against all acids except hydrofluoric acid (HF), shall be used. Additionally this type of brick has a good resistance to solutions of alkalis up to 20% by weight at room temperature, but will not withstand stronger concentrations, especially under hot conditions. For such conditions, carbon or graphite bricks should be used.

In order to provide thermal shock resistance, acid-resistant bricks with a higher apparent porosity than 12% and lower chemical resistance, such as red or blue acid-resistant bricks, may be used. The use of these bricks is subject to approval of the Principal.

Brick and tiles for accessible/passable floors shall be furnished with an adequate anti-slip provision or profiled surface.

2.3.2 Carbon and graphite bricks and tiles

Unless otherwise specified, bricks to be used shall be non-impregnated carbon or graphite bricks in accordance with DIN 28062, type 1.2.1. or type 1.2.2 respectively.

Carbon bricks with an ash content below 1% shall be used if the liquid to be protected against contains HF or strong alkalis.

Requirements for impregnated bricks and tiles and impregnated/non-impregnated graphite bricks and tiles shall be stated in the purchase order and shall be approved by the Principal. NOTE: Carbon bricks are porous but they can be made liquid-tight by impregnating them with synthetic resins

during the manufacturing process. Impregnation does not significantly change the thermal conductivity of the material, but it does improve its strength.

2.4 OTHER CERAMIC LINING MATERIALS

These special ceramic bricks and cements are usually based on: unglazed porcelain sintered alumina (Al2O3> 80%) silicon-carbide (SiC) silicon-nitride (Si3N4)

Requirements for these products shall be in accordance with DIN 28062 and shall be stated in the purchase order, after consultation with the Principal.

3. SAMPLING, TESTING AND INSPECTION

The Manufacturer shall maintain quality control/test records. He shall submit a record of inspection and testing together with a statement of compliance with this PTS.

The selected type of membrane and synthetic resin or other mortar cements shall be indicated in the requisition sheets. The Manufacturer shall be prepared to supply certificates including a reference or lot number for the materials and samples for test and reference purposes. These specifications shall not be subsequently changed prior to application without approval from the Principal.

All bricks and tiles shall have a regular texture throughout, without laminations, cavities or cracks and shall have consistent dimensions and shapes.

The number of items (bricks or tiles) to be tested shall be determined in accordance with a (standardised) sampling plan and the required acceptable quality level (AQL)