4478-50A1

JOB SPEC 4478-50A1 PIPING PAGE 2 REV 7 DATE Apr 12, 1999

ORIGINATING ENGINEER: R. Chakravarti CORE TEAM APPROVAL:

JOB SPEC 4478-50A1 PIPING PAGE 3 REV 7 DATE Apr 12, 1999 I. SCOPE

This job specification is intended to govern the design and supply of process and utility piping systems (for ISBL and OSBL), for the SINCOR Downstream Project, Jose, Venezuela. This specification is supplemented by: Job specifications, Engineering Flow Diagrams, Line Classification Lists, Line Class Piping Material Specifications and Plot Plans.

II. REFERENCES

The latest editions and revisions of the following documents are referred to in this specification:

(4) A. Job Specifications

JOB SPEC 4478-01A1, Basic Engineering Data JOB SPEC 4478-43A1, Foundations and Elevated Concrete

Structures JOB SPEC 4478-46A1, Structural Steel Design and

Fabrication JOB SPEC 4478-50A2, Gaskets and Surface Finish for

Bolted Flanged Joints JOB SPEC 4478-50A4, Dimensions of Nonstandard Gaskets

& Surface Finish for Proper Compression

JOB SPEC 4478-50A6, Special Requirements for Compressor Piping

JOB SPEC 4478-50A10, Line Class Piping Materials Specifications

JOB SPEC 4478-52A1, Shop and Field Fabricated Piping JOB SPEC 4478-52B2, Reinforcement of Welded Branches JOB SPEC 4478-56A1, Steam Tracing for Piping and

Vessels JOB SPEC 4478-58A1, Underground Piping and Surface

Drainage JOB SPEC 4478-59A1, Steam Traps JOB SPEC 4478-59B9, General Notes - Valves JOB SPEC 4478-60A1, Instrumentation JOB SPEC 4478-67A2, Steam Tracing of Instruments JOB SPEC 4478-67A3, Electric Tracing of Instruments JOB SPEC 4478-78A1, Electrical Heat Tracing JOB SPEC 4478-83A1, Painting JOB SPEC 4478-83A4, Coating and Wrapping of

Underground Steel Pipe JOB SPEC 4478-89A1, Pressure Testing at Jobsite

B. It is not practical to list all applicable industry standards

here. Such standards where applicable are referenced within the job specifications.

1. ASME/ANSI Standards

a. ASME/ANSI B16.5, Pipe Flanges and Flanged Fittings


b. ASME B16.20, Metallic Gaskets for Pipe Flanges - Ring-Joint, spiral-Wound, and Jacketed

c. ASME B16.21, Non-metallic Gaskets for Pipe Flanges

d. ASME B16.47, Large Diameter Steel Flanges (NPS 26

through 60)

2. ASME Standards (Codes)

a. B31.1, Power Piping b. B31.3, (1996 Edition), Process Piping

3. ASME Boiler and Pressure Vessel Code

a. Section I, Power Boilers

b. Section VIII, Division 1 and 2, Pressure Vessels c. Section IX, Welding and Brazing Qualifications

4. API Publications

a. API RP 520, Recommended Practice for the Design and

Installation of Pressure - Relieving Systems in Refineries Part II - Installation

b. API RP 521, Guide for Pressure-Relieving Depressuring

Systems.

c. API Std. 610, Centrifugal Pumps for Petroleum, Heavy duty chemical, gas industry services.

d. API Std. 612, Special-purpose steam turbine for

refinery services.

e. API Std. 617, Centrifugal Compressors for General Refinery Service.

f. API Std. 618, Reciprocating Compressors for General

Refinery Service. 5. Pipe Fabrication Institute Standards

a. PFI Std. ES-3, Fabricating Tolerances

b. PFI Std. ES-24, Pipe Bending Tolerances

6. Standards of Expansion Joint Manufacturers Association

7. ASTM Specifications

a. ASTM A 193, Alloy-Steel and Stainless Steel Bolting

Materials for High-Temperature Service.


b. ASTM A 194, Carbon and Alloy Steel nuts for bolts for high-pressure and high-temperature service.

c. ASTM A 307, Standard specification for Carbon Steel

bolts and studs 60,000 psi tensile strength.


d. ASTM A 453, Bolting Materials with (High-Temperature), Yield Strength and Expansion Coefficients Comparable to Austenitic Steels.


C. FIGURES: (1 through 6)


TYPICAL PIPING AT TURBINES NOTES 1. NPS 3/4 DRAIN 5. RELIEF VALVE SIZED FOR MAX. THROTTLE 2. NPS 3/4 DRAIN BEFORE STEAM FLOW TRIP & THROTTLE VALVE 6. EXPANSION JOINT AND ANCHOR TO BE (WHEN USED) INSTALLED ONLY AS REQUIRED. (OWNER=S 3. CASING AND CHEST DRAINS (APPROVAL REQUIRED) VALVED AND TRAPPED TO 7. WHEN EXHAUST NOZZLE IS UP USE PUMPING SUIT TURBINE DESIGN. TYPE TRAP ON CASING DRAIN (SARCO TYPE (ALSO SEE NOTE 7). PPP OR EQUAL). 4. TRIP & THROTTLE VALVE

SUPPLIED BY TURBINE VENDOR (IF REQUIRED)

JOB SPEC 4478-50A1 PIPING PAGE 9 REV 7 DATE Apr 12, 1999 TYPICAL PIPING AT TURBINES (CONTINUED)

NOTES 1. NPS 3/4 DRAIN 10. BYPASS VALVE (SIZED FOR 10% OF 5. RELIEF VALVE SIZED FOR MAX. NORMAL THROTTLE STEAM FLOW)

THROTTLE STEAM FLOW MAY BE INSTALLED TO ALLOW 6. EXPANSION JOINT AND ANCHOR CONTINUOUS SLOW-ROLL OPERATION

TO BE INSTALLED ONLY AS REQUIRED WHEN TURBINE AND DRIVEN EQUIPMENT (OWNER=S APPROVAL REQUIRED) ARE EQUIPPED WITH FORCED FEED LUBE

8. TRAPPED DRAIN OIL SYSTEM OR OTHER SUITABLE 9. WHEN EXHAUST PRESSURE IS HIGHER LUBRICATION PROVISIONS.

THAN 150 PSIG. CONSIDERATION SHALL BE GIVEN TO SPECIFYING EQUIPMENT SUITABLE FOR CONTINUOUS


SLOW-ROLL OPERATION.


FIGURE 5-TYPICAL VALVING AT EXCHANGERS

FIGURE 6-ISOLATION VALVING ON-BY-PASS EXCHANGER UNITS


D. General Criteria 1. Select specific elevations for lines running North and South

and other specific elevations for lines running East and West. Maintain these elevations through the unit, except where pockets must be avoided. Usual dimension between banks of pipe = 2’-0" (610 mm) (min.) to 3’-0" (915 mm).

2. Select specific elevations for short runs at pumps, control

stations manifolds, etc., and maintain these through the unit. (8’-0" (2400 mm) Min. Clearance to H.P. of paving)

3. Elevation of Lines Above Supports to be per Para. VI.A.6.

4. Flanged connections required to permit dismantling lines for

maintenance, inspections, or removal of equipment shall be provided.

5. Elevations of Paving, Floors and Equipment to be as follows

(per JOB SPEC 4478-43A1).

Note: Engineering standard & procedure dictates:

a. Top of concrete is top of grout (not top of rough concrete).

b. Platform elevation is top of steel (not top of grating or

checkered plate).

(4) (*=Reference elevations shall be based on low point of paving)

Low Point of Paving (top of Catch Basins) = Elev. * +0" (*mm) (4)(7) High Point of Paving = Elev. * +6”(*+150 mm) (7) High Point Finished Floor: = Elev. * +8”(*+200 mm) (4) Enclosed Buildings in Paved Areas = Elev. * +6"(*+150 mm)

Open Buildings in Paved Areas = Match Outer Edges with Adj. Paving

(4) All Buildings in Unpaved Areas = 6" Above Adj. (150 mm) Grade

"Top of Grout" or "Bottom of Base Plate": (4) Centrifugal Pumps = Elev. * +9" (*+225 mm)

(Min) (4) Reciprocating Pumps = Elev. *+1'-3" (*+380 mm) (Min) (4) Vertical Vessels = Elev. *+1'-0" (*+300 mm) (4) Base of Columns = Elev. *+1'-0" (*+300 mm)

6. Provide chain or extension stem for valves as specified in Para. VI.C.

Gear operators shall be provided as specified in Para. VI.A.19.

Style of gearing must be specified after layout.


7. Access to block valves shall be accomplished as described in Para. VI.C.

8. Center line of Control valves shall be located 0.61m (2'-0")

above high point of paving or first level of structures unless otherwise specified on flow diagram. Those which control level in a vessel must be located to have gage glass visible and accessible while operating by-pass valve.

For size of blocks and by pass valves, see JOB SPEC 4478-60A1.

9. Utility Station Requirements (per Para. VI.D.1).

Steam, air and water at grade: spaced so that all areas can be reached with 50'-0" (15 m) of hose.

Steam and air at alternate levels of structures and vessels (same levels as manways).

All lines to utility stations to be 1". Provide gate valve in each line at hose connection.

(6) 10. Deleted

(6) 11. Deleted

12. Orifice Flow Measurement

(4) Horizontal orifice runs are preferred. Vertical runs are permitted in upward flow only for liquids; downward flow preferred for gases. For instrument connections see Job Spec 4478-60A1.

A minimum of 2'-0" (610 mm) clearance shall be allowed from OD of orifice flange to any obstruction, for installation of meter leads.

13. Overhead suction lines shall drain toward the pump without

pockets.

14. Piping and structures shall be arranged to permit mobile lifting equipment to approach pumps control valves, other rotating equipment, safety valves etc., and make lifts without obstruction.

15. The block valve in the exhaust line of a turbine shall be

located at the turbine and down stream of a relief valve. No additional block shall be provided at the exhaust steam header. Expansion joints will not be used unless shown on flow diagrams.

(6) 16. Deleted


17. Allow for 1" (25 mm) shims (or grout) above steel (or concrete). For vessels over 15'-0" (4570 mm) dia. allow 1½” (40 mm) for shims (or grout).

18. Branches from plant air, gas and steam headers to be from top. Branches from service water header can be from bottom of header. Relief valves to discharge into top of header.

19. Platforms may not be provided for manways in horizontal or

vertical vessels where the manway centerline is 12'-0" (3650 mm) or less from grade. Assume portable ladders will be used.

20. “Dead Ends” in piping to facilitate supports shall not be

allowed in process lines.

21. ITEM MINIMUM CLEARANCES

ROADS, ACCESSWAY AND CRANEWAYS:

Headroom for Primary Access Road (Where major maintenance vehicles are expected to pass).....21'-0" (6400 mm)

Pump Maintenance Accessway Headroom.............12'-0" (3650 mm) Process Area Craneway Headroom..................17'-6" (5335 mm) Pump Maintenance Accessway, Horizontal Clearance, not necessarily in a straight line.............10'-0" (3050 mm) Clearance from edge of road to platforms, equipment, pipe, etc........................... 5'-0" (1525 mm) Normal Overhead, inside Battery Limit...........16'-0" (4880 mm) Plant Roads, Outside Battery Limit, Clearance...20'-0" (6100 mm)

RAILROADS:

Headroom from Top of Rail.......................21'-6" (6550 mm) Clearance from track centerline to obstruction.. 8'-6" (2590 mm)

MAINTENANCE PASSAGEWAYS AND WALKWAYS:

Horizontal Clearance, not necessarily in a

straight line ................................. 3'-0" ( 915 mm) (4) Headroom (except for handwheels, which may be

6'-6" (1980 mm)................................ 7'-0" (2135 mm)

CLEARANCE UNDER PIPEWAY:

Access for vehicular equipment..................12'-0 (3650 mm) Access for portable service equipment...........10'-0" (3050 mm)

PIPE ON SLEEPERS:

Clearance, bottom of pipe to finished grade, unless otherwise specified in project specifications... 1'-3" ( 380 mm)

EQUIPMENT:


Minimum maintenance space required between shells of exchangers or other equipment arranged in pairs.........................................3'-0" ( 915 mm)

(4) Minimum maintenance space required to structural

member or pipe.................................. 1'-0" ( 300 mm)


FIRED EQUIPMENT:

Clearance from edge of roads to shell...........10'-0" (3050 mm)

PIPE (ABOVE GROUND):

Clearance between outside diameter of flange and Outside diameter of pipe or insulation.......... 0'-1" ( 25 mm)

Clearance between outside diameter of pipe or insulation and structural member................ 0'-1" ( 25 mm)

III. BASIS OF DESIGN

A. Code Requirements

1. Piping shall be designed, fabricated, inspected and tested in accordance with ASME B31.3. (1996 Edition), Process Piping, including applicable addenda, in effects as last edition, and other governing codes. Piping within the jurisdiction of the ASME Boiler and Pressure Vessel Code (BPVC), Section I, power boilers, shall be designed, fabricated, inspected and tested in accordance with ASME B31.1, Power Piping.

2. Dimensions of various classes of flanges and valves shall be

in accordance with the appropriate ASME/ANSI, API or MSS Standards.

3. All welding including tack welding on pressure parts of

piping, whether shop or field, shall be by welders qualified in accordance with the ASME BPVC, Section IX, Welding and Brazing Qualifications and the ASME Code for Pressure Piping.

4. The applicable edition of the National Codes and Standards

shall be that in effect on the contract date.

B. Design Requirements

(5) 1. Discharge piping of a centrifugal pump not protected by a safety valve shall be designed for the maximum discharge pressure of the pump or compressor.

2. All systems operating below atmospheric pressure (excluding

the steam out conditions) shall be designed for full vacuum.

3. The design temperature will usually be the maximum fluid temperature plus 15°C.

4. Flanged connections inside tower skirts are not allowed.


C. Piping Material Specifications

(6) 1. Material of construction for individual piping systems and specific operating conditions shall conform to the requirements of Line Class Piping Material Specifications (JOB SPEC 4478-50A10). The Line Class Piping Material

Specifications are categorized by their flange classes. The design pressure and temperature for each line including for infrequent variations shall be determined as per ASME B31.3/B31.1 code, as applicable. All necessary data for line size and class selection must be clearly stated on the Line List established by the Engineering Department.

D. Piping Material and Sizes

1. Pipe

a. Minimum corroded thickness shall be calculated as

specified in the applicable code.

b. The corrosion allowance shall be specified on MOC (Materials of Construction)drawings. The minimum corrosion allowance used in determination of pipe wall thickness shall be as follows:

1. For carbon steel and low chrome alloys (up to and

including 5% Cr.): 0.063" (1.5mm)

2. For stainless steels and higher alloys: 0.030" (0.75mm)

c. The wall thicknesses given in the Piping Material

Specifications provide allowance for corrosion, thread depth and manufacturing tolerance in addition to the thickness required by the most severe condition which can occur. The thickness required by the most severe design conditions shall be compared with the retirement thickness as listed below. The larger of the two values shall be used in the pipe wall thickness calculations.

Nom. Pipe Size Retirement Thickness

1/2" - 3/4" 0.04" 1" - 8" 0.06" 10" 0.09" 12" - 14" 0.11"

(6) 16" - larger 0.12"

A nominal thickness of Schedule 80 or more is specified for threaded pipe. Pipe designed for welded joints shall


have a minimum nominal thickness of standard wall in carbon steel and ferritic alloys, Schedule 10S in stainless steels and higher alloys.

d. Close nipples shall not be used. All carbon steel and ferritic alloy steel screwed nipples shall be sch 160 min. Austenitic stainless steel and non-ferrous alloy screwed nipples shall be sch 40S minimum.

e. In carbon steel pipe, Grade B is specified due to its

higher allowable stresses at no higher price than Grade A. If bending is contemplated, however, the ductility of Grade A pipe is required for the bent section. Many heats have the required strength of Grade B and ductility of Grade A, allowing them to be stamped and certified to either grade.

f. Ductile iron pipe may only be used for underground water,

and sewer services, and for underground firewater service. An internal cement lining for these pipes shall be specified in the Line Class Piping Material Specifications if product is corrosive. Design temperature shall be limited to the one allowed by the soft gasket material used to seal joints.

g. No pipe smaller than NPS 3/4 shall be used, except for

connections to instruments, steam tracing, air connections to control valves, and connections to vendor’s equipment.

h. Pipe sizes NPS 1-1/4, 2½, 3½ and odd numbered sizes NPS 5,

7, etc., shall not be used. Equipment furnished with connections in these sizes shall be adjusted to a standard size immediately adjacent to the equipment by means of a special flange or reducer.

i. Welded end closures shall be welding caps for all process

service lines and for all other services with design pressures over 1.05 kg/cm2 (gauge) or in vacuum service.

j. Round head plugs shall be used.

2. Valves

(4) a. Valves shall be provided of the type and tag number (when

shown) shown in the Engineering Flow Diagrams. The type of valve shall be in accordance with Line Class piping Material Specification, JOB SPEC 4478-50A10 and procured in accordance with JOB SPEC 4478-59B9.

b. Vent and drain valves shall normally be bolted bonnet type

unless otherwise required due to process or service.


c. Valves with bodies, seal rings or linings of teflon and other plastics are limited to the maximum temperature specified in the Line Class Piping Material Specifications, JOB SPEC 4478-50A10. All soft seal valves shall be of the “Fire-Safe” type. A “Fire-Safe” certificate complying with API 607 or similar approved test must be supplied.

d. Cast iron, brass and bronze valves are limited to design

conditions and fluid services of Category D, which are not critical to the plant operability or safety. These valves shall not be installed on Instrument Air or Power Air to the valve actuators.

e. API Trim No. 8 (F6+) is generally supplied or available

for carbon steel and low chrome alloy steel valves.

f. Use of asbestos is not permitted in any packing or gasket material.

g. Where two lines of different classification connect, the

higher classification (due to pressure-temperature-conditions, required corrosion resistance or other special problems) shall prevail up to and including the first shut-off valve to the line or both shut-off valves, if the line is double-valved.

h. Valves shall be provided with pressure equalizing bypass

globe valve, as indicated below, when the operating differential pressure across the closed valve approximately equal the pressure rating of the valve at the operating temperature.

BYPASS VALVES-GLOBE

(Pipe Size in Inches)

GATE VALVE RATING AND BYPASS GLOBE VALVE SIZE

Size 150 300 400 600 900 Class

CLASS CLASS CLASS CLASS and Over

None N-A

4..... - - - 3/4

6..... - - 3/4 3/4

8..... - 3/4 3/4

10.... - - 1 1


12.... - 1 1 1

14 to 20... 1 - 1 1

24..... 1 - 1 1

3. Flanges

a. Raised face flanges shall be used for services in Class 900 and lower classes and at temperatures 538°C and below, except as noted in the Piping Material Specifications.

b. Large diameter flanges (NPS 26 and above) shall be per

ASME B16.47 Series “A”.

c. For Class 1500 and above, ring type joint (RTJ) flanges shall be used.

d. Flange surface finish shall be in accordance with JOB

SPEC 4478-50A2 or 4478-50A4 as applicable.

e. Pipe and pipe component endings shall be as follows unless otherwise shown in the Line Class specifications or requisitions.

(1) NPS 1½ and smaller, socket welding (SW). (2) NPS 2 and larger butt welding (BW), Weldneck

flanges shall be bored to suit pipe. (3) Slip-on flanges or Lap Joint flanges shall not

be used.

4. Gaskets

Gaskets shall be per JOB SPEC 4478-50A2 or 4478-50A4 as applicable.

a. Gaskets containing asbestos in any form shall not be

used. b. Compressed sheet gaskets are limited to utility services,

such as water, air, nitrogen etc. However, they shall not be used in steam services, process services or in category M fluid services. Compressed sheet gaskets shall be graphoil type with stainless steel reinforcing insert.

c. Spiral wound stainless steel gaskets shall be used for

raised face flanges unless specified otherwise. Spiral wound gaskets shall be 304SS or 316SS spiral, (when service conditions dictate), graphite filled. Graphite


to be pure with anti-oxidant and anti-corrosion agents (when specified in Line Class piping material specs). Outer ring to be provided in all cases (except for tongue and Groove design). Inner ring to be limited to vacuum services and/or required by ASME/ANSI standards for higher pressure classes. Inner ring to be 304SS or 316SS material.

d. Gasket widths shall be limited in accordance with

dimensions tabulated in ASME B16.5 Annex E. Flat gaskets in accordance with ASME B16.21 and spiral wound or jacketed gaskets in accordance with ASME B16.20.

e. Where ring joint closure is specified, ring material shall be soft carbon steel for carbon steel flanges, 4-6% Cr 1/2% Mo for ferritic alloy flanges and 18-8 Cr-Ni for austenitic alloy flanges. Ring shall be oval cross-section. Maximum hardness of ring joint gasket material is per Table 1, ASME B16.20.

5. Bolting

a. When bolting Class 250 CI flanges to Class 300 steel

flanges, carbon steel machine bolts (ASTM A307GR-B) may be used for services at design temperature of -29ΕC to 204°C. The gasket used shall be per Group No. 1a material, ASME/ANSI B16.5.

b. ASTM A193 Gr. B7 alloy steel stud bolts shall be used at

design temperatures of -29°C to 427°C for carbon and low alloy steel flanges (up to 9% Cr.). For design temperatures from 427°C to 538°C, Gr. B16 shall be used. (Note: 20% temperature reduction on uninsulated flange bolting cannot be used)

c. For stainless steel flanges, ASTM A193 Gr. B7 alloy steel

bolts shall be used at design temperatures of -29°C to 370°C, ASTM A453 Gr. 660 stainless steel bolts from 370°C to 538°C. ASTM A193 Gr. B8M Class 2 stainless steel bolts shall be used at design temperatures below -29°C.

6. Fittings

a. Socket welding fittings shall be used for NPS 1½ and

smaller, unless otherwise specified. Butt-welded fittings shall be used for larger sizes.

b. Threaded fittings are acceptable in NPS 1½ and smaller

size piping whose fluid service is designated Category D and in instrument service and atmospheric vent or drain piping downstream of the last block valve.


7. Branch Connection

a. Welded pipe to pipe connections shall be designed so that the angle of intersection between the branch and the run shall not be less than 45°.

b. Integrally reinforced branch welding fittings which abut

the outside surface of the run wall, in sizes 4 in. NPS (100mm) and larger, are not permitted under any of the following conditions:

1. The d/D ratio (branch diameter/run diameter)

exceeds 0.8. 2. The run piping wall thickness is less than

standard wall.

3. The run piping wall thickness is less than 0.375 in. (9.5mm) where outside diameter exceeds 36 in. (900mm).

c. Pad-type reinforcement for full size branch connections

is not permitted.

d. Connections NPS 1½ (40 mm) or smaller shall be welded to run piping by using a coupling, or a schedule 160 or greater nipple, or an integrally reinforced branch welding fitting.

8. General Installation Requirement

a. Provisions for expansion shall normally be made with pipe

loops. Cold strain shall be avoided.

b. All piping systems shall be designed so that the loads and moments applied at the flanges of mechanical equipment such as pumps and compressors, shall not exceed the permissible reactions for the equipment.

9. Supports and Anchors

a. All piping shall be supported and shall be provided with

anchors, sway braces or vibration dampeners to prevent excessive expansion forces on equipment and excessive vibration.

b. Piping at valves and mechanical equipment, such as pumps,

requiring periodic maintenance shall be supported so that the valves and equipment can be removed with a minimum necessity of installing temporary pipe supports.

10. Responsibility of the Owner


In accordance with Para. 300 (b) of ASME B31.3, the owner is responsible for identifying these fluid services which are in categories D and M as defined in Para. 300.2.

11. Safeguarding

When safeguarding is required by ASME B31.3, its Appendix G shall be used as a guide toward selection of appropriate safeguarding.

IV. PROCESS SYSTEMS GUIDELINES

The following guidelines are generally reflected in the preparation of the Engineering Flow Diagrams (EFD). In case of any conflict, the EFD shall govern.

A. Towers and Drums

1. Block valves shall be provided at tower nozzles in the following instances:

a. Each line feeding process steam or purge gas to a tower.

A NPS 3/4 bleed connection and a check valve shall also be provided, immediately upstream of the block. These are in addition to the block valve normally provided at the header. The bleed connection can be in a drip ring between the valves, or in either valve body.

b. Where a line connects to a tower below the liquid level,

and there is no other valve before the next piece of equipment nor within 15 m (50 feet) on a horizontal radius from the tower and accessible from grade or a platform.

c. Vent and drain lines.

d. Pumpout lines which discharge to a closed pumpout system,

plus a second block and a NPS 3/4 bleed valve located between the two valves.

e. Process lines operating above 370°C.

f. Unless otherwise indicated on the P&I flow diagrams, the

piping systems for pumping out towers and equipment shall be a part of the regular process piping of the unit.

2. Block valves shall not be provided at the tower in the

following:

a. Reflux return lines above the liquid level, where block valves have been provided at the pump discharge.


b. Fractionator draw-off line providing liquid to side stream stripper, when the line includes a control valve with blocks and by-pass.

3. No block valves will be provided in the following:

(6) a. Relief valve connections on vessels and drums.

b. Stripper vapor return lines to fractionating towers.

c. Vapor overhead lines from towers.

d. Thermo-syphon reboiler suction and return lines.

e. Gravity intercooler suction and return lines. B. Pumps

1. A block valve shall be installed in both the suction and

discharge lines of each pump. The rating of the discharge valve shall be determined by the design conditions of the line. The suction valve will usually be rated for the design conditions of the suction line. Where the piping of two or more pumps is manifolded, see Para. IV.B.9.

2. Where the pump inlet nozzle is one or more sizes smaller than

the line size, the block valve may be nozzle size if pump hydraulics permit. Review conditions with Mechanical Equipment Engineer.

3. A check valve shall be installed in the discharge line of a

centrifugal or rotary pump between the pump nozzle and the block valve. Reciprocating pumps shall not normally be provided with a check valve.

4. Overhead suction lines shall drain toward the pump without

vapor pockets.

5. Casing vents and drains shall be provided as shown on the Auxiliary Flow Diagrams.

6. A temporary strainer shall be provided upstream of each pump

suction nozzle during break-in operations. A Y-type strainer with a 1/16" diameter perforated stainless steel screen shall be used in NPS 2 and smaller. In larger sizes, a cone type carbon steel plate strainer with 3 mm (1/8") diameter perforations, having an open area equal to 200% of the internal cross-sectional area of the pipe, shall be installed between FF or RF flanges, pointing upstream. In lines with RTJ flanges, a strainer fitting inside the ring gasket, Aitken C-2 or equal, shall be used. Since the temporary strainer must be removed and its collected sediment


discarded, it shall be installed in a short flanged section. Flat plate strainers shall not be used.

7. A warm-up bypass system, as illustrated in Figure 1, shall be

provided between a pump and its spare when the spare must be brought close to operating temperature before switch-over, kept at operating temperature in anticipation of automatic switch-over, or kept warm in winter. If a high differential pressure precludes meeting the 3 to 5% normal pump flow limitation, a bypass with a flow restrictor is acceptable on pumps with discharge nozzles 2 in. NPS (50 mm) diameter and larger. Drilled check valve may only be used as an alternate in special cases with Owner’s approval.

8. A suction line to a centrifugal pump with side or end entry

shall be installed with an eccentric reducer (flat on top) adjacent to the pump nozzle or nozzle size valve. A reducing elbow may be used when the space for a long radius elbow and eccentric reducer is not available, and the layout will allow the temporary strainer to be fitted inside and later removed with its collected sediment.

(6) 9. Suction lines to centrifugal pumps with double suction

impellers shall be piped with split flow to the inlet nozzle to prevent impeller damage due to unequal flows.

10. Pumps with top suctions shall utilize concentric reducers.

11. If the discharge block valve is open and the check valve

malfunctions, the suction piping may be subjected to pump discharge conditions for short periods. Where this can occur, the suction block valve and any piping downstream shall be designed per Para. 302.2.4 of ASME B31.3 unless means of relieving the accidental overpressure are provided.

12. Piping shall have adequate flexibility and support to prevent

expansion or dead loads from imposing damaging strains on the pump casing.

13. A NPS 3/4 drain shall be installed on the discharge side of

the check valve body or downstream of the check valve, depending on size. See Figure 1.

14. Piping shall be arranged to allow the removal of the pump for

maintenance. In-line pumps with motor drives not exceeding 60 KW may be supported directly by suction and discharge piping, with distance between pump flange and pipe support centerline not to exceed 1½ times the pipe diameter.

15. Pump suction and discharge block valves shall be located in

an accessible location or shall be provided with chain wheels.


16. A low flow protection system shall be installed for pump expected to operate for extended periods of time at less than 20% of their best efficiency point (BEP) flow rating. The low flow protection system shall be designed to assure continuous pump operation at flows exceeding 20% of BEP flow rating.

17. The low flow protection system shall either be piped back to

the pump suction source upstream of the suction valve or through a cooler and back to the pump suction. Alternative system design shall be submitted to the Owner’s Engineer for approval.

18. In Boiler Feed Water pumps, an automatic combined low-flow-

bypass/check valve shall be provided for each pump (in lieu of an unvalved Orificed bypass).

C. Compressor

1. Reciprocating compressor must have a recirculating line

between discharge and suction piping which shall accommodate 50% of full design flow rate. This line is equipped with a manual block valve which is closed in normal operation.

2. Reciprocating compressor shall be provided with a check

valve.

3. Centrifugal compressor must have an anti-pumping (anti-surge) line between discharge and suction piping equipped with an anti-pumping valve driven by the automatic control system of the compressor.

4. Suction piping from the knock out drum to the compressor must

be as short as possible and its diameter shall normally be not less than one of the inlet nozzle of the compressor unless otherwise required by the process engineering, or if the vendor would charge extra to change the nozzle size for customizing the equipment.

5. Piping to be without low points between knock-out drum and

Anti-pulsation Bottle (Reciprocating Compressor) or inlet nozzle flange (for other compressor type). Piping to be sloped downward from the compressor to knock out drum.

6. All suction piping must be equipped with a filter (strainer).

The filter (strainer) shall be installed upstream of the anti-pulsation bottle in case of the reciprocating compressor.

7. For maintenance purpose, suction piping must be equipped with

a block valve and a blind (fig 8 or paddle depending on the line size) on the compressor side. Automation emergency isolation block valve may be required if specified on P&ID.


8. The individual discharge piping of a compressor must be equipped with a quick response, non slam type check valve whatever the compressor type.

9. For maintenance purpose, discharge piping must be equipped

with a block valve with a fig. 8 blind on the compressor side. For high pressure compressor (over 900# series) considerations must be given to double block and bleed valves. Automated emergency isolation block valve may be required if specified on P&ID.

10. Process and auxiliary piping shall be arranged in orderly

fashion around the compressor and in such a way as to allow maintenance work and general overhaul with a minimum of piping dismantling. The upper half of body of centrifugal compressors and the blind end cover of barrel compressor shall be easily removable.

11. Piping diameters must be selected to allow for reasonable

linear velocities of gases and pressure drop in the lines.

12. Block valves and check valves shall have same nominal diameter as the line.

13. Unless temperature limits their use, soft seal fire safe ball

valve as per applicable piping class shall be used a block valves. Ball valves to be full port.

14. All piping materials (valves, flanges) shall be rated (following ANSI B16.5) for the highest possible design conditions they may experience. For instance the block valve and downstream piping on the suction line may be rated for the high pressure outlet conditions in the case of several compressors running parallel.

15. Each stage of a volumetric compressor must be protected

against over pressure by a safety valve.

16. Loads from piping (in the cold and hot conditions) on the compressor nozzles shall be limited to the values allowed by API standards 617 & 618. This shall be achieved by appropriate supporting of the lines and proper flanges alignment. During erection flange faces parallelism shall be achieved within 0.8 mm and bolts shall not be forced through bolt holes.

17. In vibrating services, gusseting on small bore connections

should be considered.

18. Silencers, if required, shall be installed in the suction and discharge piping as close to the compressor nozzles as practicable. In order to optimize layout, the silencers may


be arranged with side or end connections. Silencer shell and flanges shall conform to the appropriate piping material specifications.

D. Turbines

1. Where two or more turbines have a common control valve, a

block valve shall be provided in the steam inlet line to each turbine.

2. The exhaust side of each turbine shall have a separate block

valve, located at the turbine downstream of the relief valve. This location permits maximum safety in determining whether the valve is open or closed. No additional block valve shall be provided at the exhaust steam header.

3. Manufacturers normally provide turbines with permanent integral strainers. Where removal of such strainers is effected through the inlet piping, a flanged spool piece or other means for easy access shall be furnished. If a turbine without an integral strainer is to be used, a Y-type strainer with blowdown valve shall be indicated on the Engineering Flow Diagram and installed in the steam inlet line as near to the turbine flange as is feasible. Y-type strainers shall have stainless steel screens with 0.80mm (.033") perforations.

4. Regulating, throttling or control valves shall be accessible

for hand operation. When used in conjunction with an indicator which responds to the operation of a valve, the two shall be located so that the operator may observe the response from his position at the valve.

5. Expansion joints (Owner’s approval required) shall be provided for turbine exhaust steam lines as shown on the Engineering Flow Diagram.

6. Drain connections, with steam traps to remove condensate,

shall be provided at the low point on the turbine inlet line before the block valve. For turbines on automatic start-up, traps shall be connected as close as possible to the inlet side of the automatic start valve as well as the low point of the inlet line. Traps are also required for draining the turbine casing and pockets within the turbine.

7. A drain with steam trap shall be provided at the low point of

the exhaust line, downstream of the block valve.

8. Turbine exhaust piping and its safety relief shall be as follows:

a. Condensing Turbines


A full capacity relief valve shall be provided for turbine exhaust condensing at atmospheric or sub-atmospheric pressure and discharging to a surface type condenser. This relief valve can be installed on the turbine, in the piping or furnished with the condenser. Only one such valve is required where a condenser serves more than one turbine. The capacity of the relief valve shall not be less than the total possible steam flow from all turbines connected to the condenser.

If a block valve is specified by the client, in the exhaust line to the condenser, the block valve shall be car-sealed open, if no relief valve is provided upstream of it. For steam flows higher than 55,000 kg/hr, requiring an atmospheric relief valve, NPS 20 or larger, Purchaser shall have the option to use a full capacity rupture disc mounted on the turbine exhaust casing, instead of the atmospheric relief valve on the condenser.

If the discharge is to a barometric type condenser, no relief valve is required, but the barometric leg shall be checked to be sure its size is adequate to provide required relief.

b. Turbines Exhausting to Atmosphere Only

Neither a block valve nor a relief valve shall be provided in the exhaust line.

c. Turbines Exhausting Above Atmospheric Pressure

A full capacity relief valve shall be installed upstream of the exhaust block valve of each non-condensing turbine.

9. Turbines arranged for automatic start can sit idle with full rated exhaust pressure in the casing and no controls to maintain readiness except the automatic steam control valve and traps shown in Fig 4. A bypass around the control valve may be used to run the turbine continuously at a slow-roll speed if the turbine has suitable lubrication provisions. Provision for slow-roll operation shall be applied on an individual basis.

E. Shell and Tube Exchangers

1. Except in Category M service, block valves shall not be

provided on the process side of shell and tube equipment,


unless isolation of the exchanger tube bundle or shell is necessary during operation. Block valves at exchangers in process units shall be the exception, not the rule.

2. Block valves are required for each exchanger cooling water

supply and return line when several units are in common service and the ability to take one or more out of service during operation is required to avoid shutdown.

3. Where isolation is not required, a block valve shall be

placed only in the cooling water return line from the cooler.

4. Stacked units operating with shell sides in common service shall have only the top unit vented and the bottom unit drained, unless the shell cover is of a larger diameter than the shell. For this type of exchanger, vents and drains shall be provided on all shell covers. Vent and drain valves provided on shells and shell covers shall be NPS 1 ½ min., flanged.

5. Where block valving is not required at the bottom connections on shell and tube nozzles, and drainage can be accomplished through existing piping, drain valves shall not be provided.

6. Where valves are to be located immediately adjacent to the

nozzles of heat exchanger units, the NPS 1½ flanged vent or drain when required shall be located inside the valve, on the connecting pipe.

7. On heat exchangers provided with annular distribution, NPS 1½

flanged vents and drains shall be provided on the high and low points of these annular distributors.

8. See Figures 5 and 6 for illustrations of the above.

F. Control Valves and Orifice Flanges

(4) 1. Control valve arrangements and details shall be in accordance

Engineering Flow Diagrams. Arrangement shall be based on removal for maintenance. No provision will be made for servicing internals in place.

(4) 2. Orifice flanges and the minimum straight run of pipe upstream

and downstream shall be in accordance with JOB SPECS 4478-60A1.

G. Relief Valves

1. Relief valves shall be in accordance with JOB SPEC 4478-60A1.

2. Reactive forces caused by rapid opening of relief or control

valves shall be calculated in accordance with API RP520 Part


II, Para. 2.4. Adequate means to absorb or resist these forces shall be provided.

3. Relief valve discharge lines from adjacent equipment may be

combined into a common discharge header, providing the header is of sufficient size that the relieving capacities of the valves are not affected. When combining such lines, special consideration shall be given to thermal expansion of the piping system and the effects of back pressure on relief valve settings. Headers shall slope 6.4mm (1/4") in 3,000mm (10 feet) toward the battery limit or the disposal point (flare stack or blowdown drum).

4. Relief valves which discharge into a common header shall

discharge into the top of the relief header. Valves shall be located above the header. If not, a drain valve shall be provided at the low point of the piping and shall be piped to a safe location. Piping below the header shall be heat traced if necessary.

5. Relief valves which discharge to atmosphere shall exhaust at a safe distance away from any personnel area. A 6.4mm (1/4") diameter weep hole (drain) shall be drilled in the underside of the elbow below the point of discharge line. The exhaust discharge pipe to extend at least 3 meters above any platform or working area within a 7.6 meter radius of the point of discharge.

6. Relief valves shall be connected to flare or other disposal

system only when so indicated on the applicable P&I flow diagrams.

7. Relief valves have a minimum of piping between the protected

line or equipment and the valve inlet and shall be accessible.

H. Expansion Joints

1. Expansion joints of any kind and flexible/hose piping shall

not be used without owner’s approval

2. Only the packless type of expansion joints shall be considered. They shall be adequate for the following conditions as defined in the requisition:

a. Axial deflection b. Transverse deflection c. Angular rotation d. Design pressure-temperature of the system e. Test pressure f. Maximum Forces on Connected Piping and Equipment


3. Systems in which expansion joints are installed shall be controlled by suitable anchors, guides, supports, or stops to avoid deflecting the joints beyond their designed limits or imposing damaging forces on the joints in the shut-down condition.

4. Unless otherwise specified by supplementary design data,

material selection for the flexible elements and external attachments such as lugs, rods, etc., shall be as recommended by the joint manufacturer. The material for the other components shall be in accordance with the Piping Material Specification of the line in which it is to be installed.

5. The design, manufacture, testing and installation of

expansion joints shall be in compliance with the latest edition of Standards of the Expansion Joint Manufacturers Association, Inc.

I. Vents and Drains

1. Vents and drains shall be NPS 3/4 minimum, except as

otherwise noted on the Engineering Flow Diagram or equipment drawing. Those intended only for testing piping will not be shown on Engineering Flow Diagrams.

2. Vents and drains required while the unit is operating must be

valved and will be shown on the flow diagrams. For all piping vents and drains shall normally consist of a branch connection per JOB SPEC 4478-50A10, and an extended body valve per API 602. From equipment and small lines, the branch and its reduction to valve size shall use an appropriate combination of fitting, reducer and nipples. The valve and last nipple may be combined by using an extended body valve per API 602 with required end connections.

(7) 3. Vents and drains required only while the unit is not

operating, as for hydrostatic test, shall be the same as above for carbon steel piping. In alloy and stainless steel piping, they shall consist of a branch connection per Line Class Material Specification, JOB SPEC 4478-50A10, a nipple of sufficient length to protrude through the insulation, and a socket weld cap. The field shall supply carbon steel valves for testing alloy piping and remove them when testing is completed.

4. High points of all lines shall be vented and low points

drained except where the line can be vented or drained elsewhere; e.g., a high point need not be vented where it is connected to a tower with no block valve or lower piping between. The amount of vents and drains shall be kept to a minimum.

5. No permanent drains or vents shall be provided in Hydrogen

carrying lines. Any vents or drains installed for


hydrostatic testing shall have valves removed and connections plugged and welded after testing.

6. A 3/4 inch drain shall be installed upstream of each control

valve, between block valve and control valve.

7. Pumps, compressor, turbines, heat exchangers and their piping shall be vented and drained in accordance with Paragraphs IV.B through IV.E.

J. Sample/Sample Coolers

1. Sample connections and sample coolers shall be supplied to the extent shown on the P&I flow diagrams. Avoid long dead legs.

2. All sample connections shall normally be 3/4 inch.

3. For pipe in a horizontal or inclined plane, the sample

connection shall be located at the side of the pipe unless otherwise indicated on the P&I flow diagrams.

K. Heat Steam Tracing

1. Heat Tracing of Instruments

a. Heat tracing of instruments and their lead lines shall be

in accordance with:

JOB SPEC 4478-67A2 - Steam Tracing of Instruments JOB SPEC 4478-67A3 - Electric Tracing of Instruments

2. Steam Tracing

a. Where specified on the Engineering Flow Diagrams, steam

tracing of piping and equipment shall be used for the following purposes:

1. To maintain viscous materials in a fluid

condition.

2. To preheat process lines and avoid change of phase in cold lines while starting up.

b. Steam tracing shall be in accordance with JOB SPEC 4478-

56A1.

3. Electrical Heat Tracing

Electrical heat tracing shall be in accordance with JOB SPEC 4478-78A1.

JOB SPEC 4478-50A1 PIPING PAGE 34 REV 7 DATE Apr 12, 1999 V. UTILITY SYSTEMS PRACTICES (In case of any conflict the EFD shall

govern)

A. Live Steam and Exhaust Steam

1. Live and exhaust steam mains shall be located on overhead pipe racks and shall have block valves at or near the Unit Limit in order to isolate the process unit from the rest of the plant.

2. Steam take-off lines and exhaust steam return lines shall be

connected to the top side of the headers. Side connections shall be avoided, except where clearances do not permit top connections.

3. Block valves shall be provided in branch lines from steam and

exhaust steam headers; these shall normally be located at the steam header. Where a line operates at less than 3.5 Bar(g) (50 psig) and a valve is provided elsewhere, no valve shall be provided at the header. Note also the exception taken in Paragraph IV.D.2, stating that turbine exhaust steam valves shall be at the turbine, with no valve at the header.

4. Steam traps shall be provided for steam separators, header

drainage pockets, and low points in lines where required. Piping of traps shall be as shown in JOB SPEC 4478-59A1.

(6) 5. Steam trap discharge and other condensate lines may be reused

as boiler feed water or discharged to the nearest sewer hub or catch basin, as stated in Job Specification 4478-59A1.

6. Single block and check valves shall be provided adjacent to

the point of injection of steam into any process stream.

7. Steam relief valves shall discharge to atmosphere through discharge piping extending at least 3 meters above any platform or working area within 7.6 m radius of the point of discharge.

8. The low point of the relief valve outlet piping shall be

provided with a 9 mm minimum weephole when discharging to the atmosphere.

9. All steam lines shall be designed to avoid unnecessary traps.

10. Traps which discharge to a high pressure condensate system

generally be provided with a bypass with globe valve and two block valves.

11. Traps which discharge to a low pressure condensate or

discharge to the open air will have no bypass.

12. Before each steam trap inlet, a free blow type drain valve shall be installed in direction of flow.


B. Purge Steam

1. Purge steam lines shall be permanently connected to combustion chambers and header boxes of fired heaters or elsewhere as indicated on the Engineering Flow Diagrams.

2. Purge steam shall be taken from the nearest point on the

steam supply header to the unit. 3. Branch lines from the header, location and arrangement of

steam traps and the disposal of condensate shall be as specified for Live Steam, except that lines used solely for purge steam shall not have valves at the header, regardless of pressure.

C. Cooling Water

1. Cooling water shall be distributed to the various users

throughout the unit in an aboveground steel pipe system, where practicable. The Engineering Flow Diagrams or supplementary design data shall specify whether the cooling water system will be above or below ground.

2. Cooling water supply and return lines shall have block valves at the unit limit. Valving for a user shall be above ground and shall be located at the user. Header valves shall not be provided on branch lines.

3. When the cooling water is to be distributed as an underground

system, all instruments and unit limit block valves shall be installed in gravel bottom boxes.

4. Small branches (NPS 1½ and less) from the cooling water

header shall be taken from the top of the header to avoid blockage. Larger branches may be taken from the top or the bottom of the header, to suit the specific layout requirements.

5. Where the manufacturer's service rating of cooling water

jackets on equipment is less than the pressure of the water used, provisions for a pressure reducing valve and relief valve shall be made upstream of the connections to the equipment.

6. All process cooling water lines shall be configured so that

the equipment being cooled will remain full of water in the event of shutdown of the cooling water pumps.

D. Utility Water

1. Utility water is a fresh water system utilized for utility

stations. This system may provide cooling water for remote


equipment not easily connected to the cooling water system. Refer to Engineering Flow Diagrams for scope.

2. Take-off lines from the utility water header shall preferably

be taken from the bottom of the header. Block valves are required for every takeoff and shall be located at the user. No branch line valves shall be provided at the header.

3. Utility water shall be piped to utility stations at grade

only, as noted under Utility Hose Stations, Paragraph VI.D.1. E. Potable Water 1. Safety showers, eyewash stations, drinking and toilet

facilities will be supplied from the potable water header. F. Plant Air

1. Unless otherwise specified, the air supply for plant air shall enter the unit from an outside source, with a block valve installed in the line at the unit limit. This air shall be used as follows:

a. As an auxiliary source of instrument control air.

b. For process or other purposes where indicated on the Engineering Flow Diagrams.

c. For utility stations, as noted under Utility Hose

Stations, Paragraph VI.D.1.

2. Branch lines from the plant air header shall be taken from the top of the header. Block valves are required for every branch, located at the user rather than at the header.

3. Drain valves shall be provided at low points in the header to

free the system of water that may collect.

4. Air filters or separators shall not be provided in the plant air system unless shown on the Engineering Flow Diagrams.

G. Instrument Air

1. Unless otherwise specified, instrument air supply shall enter the unit from an outside source, with a block valve at the unit limit.

2. Where the instrument air supply is taken from the plant air

system, its inlet shall be upstream of all block valves.

3. Branch lines from the instrument air header shall be taken from the top of the header. Block valves are required for every branch, located at the header.


4. Dehydration of instrument air piping shall be as described in JOB SPEC 4478-01A1.

VI. ARRANGEMENT

A. General

1. Generally, piping shall be run overhead within the unit limits. Exceptions are fire water lines and drain lines.

2. The tops of catch basins shall be flush with low point of

paving. The tops of manholes shall be flush with the paving and at least 2"(50mm) above grade in unpaved areas.

3. For the purpose of this standard, "screwed lines" are defined

as lines in which screwed or socket welded type fittings are used or specified and "flanged lines" as lines in which flanges or butt-welded type fittings are specified.

4. Specific elevations shall be selected for lines running North

and South and other specific elevations for those running East and West. These elevations shall be used throughout the unit, except where pockets must be avoided.

5. In overhead pipe racks (yard piping) the small diameter pipe

shall be intermixed with the large diameter pipe.

6. Uninsulated piping shall rest directly on pipe support steel. Insulated hot piping with 75mm (3") thick or less insulation shall be mounted 100mm (4") above support steel, using steel shoes. Insulated hot piping with insulation thickness greater than 75mm (3") and up to 125mm (5") shall be mounted 150mm (6") above support steel. Shoes will normally be welded to the piping, but may be bolted or clamped (e.g., if piping is ferritic alloy or thin wall stainless steel.)

Insulated cold piping with insulation thickness up to 90mm (3½”) will be elevated 100mm (4") above support steel. For cold insulation thicknesses 100mm (4") and above, lines will be elevated the insulation thickness plus 25mm (1") above support steel. Commercially available foam blocks with steel wear plates will be used.

7. Piping and structures shall be arranged to permit mobile

lifting equipment to approach process equipment and make lifts without obstruction.

8. Wherever possible, the center lines of top discharge nozzles

of pumps and the center lines of channel nozzles of exchangers shall be in line.


9. In sizes through NPS 24, changes in direction shall be made with fittings unless other considerations dictate the use of bent pipe.

10. Bent pipe may be used to change direction where:

a. It costs less and space in the pipe rack layout will

allow. b. The bend radius required is not standard for fittings. c. Flow requirements dictate its use.

11. Bent pipe shall have a minimum center line radius in

accordance with PFI Std ES-24, but not less than 5 times the nominal pipe size. The required radius shall be noted on the piping drawing.

12. Miter bends shall not be used.

13. Butt-welded elbows shall be long radius type (1½ D), wherever

possible. Exceptions shall be noted on the piping drawings.

14. Changes in sizes for NPS 1½ and smaller shall be made with reducing tees or swaged nipples. For larger lines, a reducer shall be used for in-line changes and reducing branch connections shall be per JOB SPEC 4478-50A10 and 4478-52B2.

15. Class 125 cast iron flanges and flanges on steel pipe, valves and fittings that bolt to Class 125 cast iron equipment, valves, or fittings, shall have flat faces. Joints which include a Class 125 cast iron flange shall use a full face gasket and alloy studs.

16. When Class 300 flanges on steel pipe, piping components, and

equipment are bolted to Class 250 cast iron flanges, raised faces shall not be removed from the flanges, but carbon steel bolts to ASTM A 307 Gr B shall be used.

17. Flanged valves or fittings having bolt holes which do not

straddle the centerline shall be noted on the piping drawings.

18. A blind shall be provided for insertion on the outlet side of

each unit limit block valve in process services, in steam services of 10.3 Bar(g) and higher, and in other utility services whose design conditions are beyond the limits of Category D.

(4) 19. Valves with gear operators shall be per Line Class Piping

Material Specification JOB SPEC. 4478-50A10. Geared handwheels shall be supplied with valves as follows:

JOB SPEC 4478-50A1 PIPING PAGE 39 REV 7 DATE Apr 12, 1999 ANSI Primary Rating Class

VALVE TYPE AND SIZE (NPS)

Gate or Globe

Ball or Plug

Fire-safe Butterfly

in.

mm

in.

mm

in.

mm.

150 (1)

14

350

8

200

8

200

300 (2)

10

250

8

200

6

150

400

8

200

6

150

4

100

600

8

200

6

150

4

100

900

6

150

4

100

-

-

1500

4

100

3

80

-

-

2500

3

80

3

80

-

-

Notes: (1) Includes ANSI Class 125 and 250 cast iron (2) Includes ANSI Class 300 ductile iron

20. Spring Hangers shall be made accessible for their maintenance

and to facilitate pulling of the shipment pins.

21. All piping shall be routed for the shortest practical run and have a minimum number of fittings consistent with provision for flexibility.

22. The use of pipe trenches within units shall be avoided.

23. Pockets shall be avoided in all lines.

B. Clearances

1. The minimum clearance between the high point of the yard

paving and the underside of the lowest pipe support or pipe shall be 12'-0" (3650 mm) in trucking areas, 8'-0" (2400 mm) elsewhere. Piping over railroad spurs shall be so arranged that a minimum distance of 21'-6" (6550mm) exists between the top of the rail and the underside of the lowest pipe support


or pipe unless other regulations govern. Consideration should be given to maintaining an aisle for access by mobile lifting equipment.

(4) 2. The minimum clearance in pedestrian areas below handwheels,

pipe lines, flanges, etc., from platforms or high point of paving or building floors shall be 7'-0" (2135 mm). In operating aisles where mobile lifting equipment will operate, clearance shall be 10'-0" (3050 mm).

3. Normally, the spacing of mechanical equipment (pumps,

exchangers, etc.) shall be arranged to provide a minimum clearance of 2'-6" (760 mm) between foundations, or any projection of adjacent equipment, piping, flanges or valve stems. To conserve space, however, small pumps may be paired and placed on one block; exchangers may be paired to allow room for maintenance only on one side and operation on the other.

4. The operating aisle shall be located at the driver end of

pumps and shall have a minimum free width of 5'-0" (1525 mm) between any projections. Where a column is located between pumps there shall be a minimum of 2'-6" (760 mm) clear between the column and any projection on the operating side of the pump.

5. Exchanger piping and pipe supports shall be located so that

they do not interfere with the removal of channel covers and tube bundles when mobile lifting equipment is used. For exchangers located at ground level, piping shall not extend past the channel cover.

6. Fired heater tube removal areas shall be kept clear of all

piping and pipe supports.

7. Where commercial style bolt tensioners are specified, adequate clearance shall be provided around flanged connections for installation and operation of the bolt tensioners.

8. To permit access for the removal or maintenance of a pipe line, a minimum side clearance of 25 mm shall be provided between parallel lines, outside of insulation or between flange and pipe (insulation).

a. Thermal movements shall be taken into consideration in

determining side clearances.

b. Clearance for maintenance personnel shall be allowed for removal of interior lines in multiple pipe line racks.


C. Accessibility

1. Chain wheels as a general rule shall be avoided. Inaccessible block valves (center line more than 7'-3" (2210 mm)above operating level) which are required for normal operation shall be provided with chain wheels (only if necessary) or extension stem operators.

2. Chain wheel operators shall not be used on valves in sizes 2

inch and smaller. Extension stems shall be provided instead.

3. Drawings will indicate the lengths of the chains or extension stems. Chain lengths should be such as to clear the operating level by 3'-0" (915 mm).

(6) 4. Battery limit valves to be accessible from grade or operators

platform at grade.

5. Instrument connections shall be oriented so that the instruments will not obstruct aisles or platforms.

6. Wherever possible, level gauge glasses and level instruments

shall be adjacent to each other, and the gauge glass shall preferably be visible from the valve which controls the level in the vessel.

D. Miscellaneous

1. Utility Hose Stations

a. Utility hose stations providing steam, air and water

shall be located at convenient points at grade so that all parts of the unit may be reached with 50'-0" (15 m) lengths of hose. Hose, hose connections, and hose reels shall not be furnished.

b. Utility hose stations providing steam and air only shall

be located as follows:

1. At alternate levels of elevated structures so that all parts of the structure may be reached with 50’-0" (15 m)lengths of hose.

2. At alternate platforms required for servicing of

manholes in towers or vessels.

c. The supply for utility hose stations shall be taken from the steam, plant air and service water headers previously described in this specification.

d. Supply lines shall be NPS 1 and shall be provided with

gate valves of the appropriate material specification.

2. Figure 8 Blinds, Paddle Blinds and Ring Spacers


a. Figure 8 blinds, paddle blinds and ring spacers shall be installed where indicated on the Engineering Flow Diagrams.

b. Blinds (spacers and spades) shall normally be installed

on all process lines at battery limits and where required to facilitate testing, inspections or maintenance of equipment.

c. Paddle blinds shall be used for piping NPS 14 and larger,

where the weight of a Figure 8 blind would make its operation impractical. Where the piping arrangement is such that the pipe cannot be easily sprung for the thickness of the paddle blind, a ring spacer shall be used.

d. Figure 8 blinds shall be used for piping NPS 1 through

NPS 12.

e. Paddle blinds, figure 8 blinds and ring spacer material shall be in accordance with Line Class Pipe Material specification. Blinds and spacers shall have separate handle configuration for identification.

f. Special handling devices, such as davits, shall not be

provided for lifting blinds and spacers.

g. Gasket surface finish shall be in accordance with JOB SPEC 4478-50A2 or 4478-50A4 as applicable.

3. Completed pipe racks for new facilities (Grass Root) shall

have 10 percent of available space unused. VII. DRAINAGE AND SEWAGE SYSTEMS

Separate drainage and sewage systems shall be designed in accordance with JOB SPEC 4478-58A1, Underground Piping and Surface Drainage.

VIII. OFFSITE PIPING

A. Wherever possible, offsite piping shall be located in banks at grade and supported by concrete piers or sleepers.

B. Where double pipe banks are required, steel columns and supports

built up from concrete piers or sleepers shall be used. As a minimum, a clearance of 3'-0" (915 mm) between the two banks shall be provided.

C. Overhead pipe racks shall be kept to a minimum.


D. Where piping at grade is required to cross a road, it shall pass under the road with a minimum cover height of 3'-3" (1.0m). Where the pipe is insulated, a sleeve shall be buried to the same minimum cover height, and the insulated pipe passed through it.

E. Clearance between the high point of a road and the underside of

the lowest overhead pipe support shall be 20'-0" (6100 mm). Clearance over railroad spurs shall be in accordance with Paragraph VI.B.1 of this specification.

F. The minimum height of concrete piers or sleepers shall be 1'-0"

(305 mm).

G. Wherever possible, changes in direction shall be accomplished by flat turning.

H. Changes in direction shall be made with fittings.

J. Consideration shall be given to expansion of pipe as a result of

process or climatic conditions. The expansion shall preferably be absorbed by the use of loops or bends. Vertical loops are acceptable except in gravity flow. The use of expansion joints shall be avoided.

K. Consideration shall be given to providing flexibility in the

piping to storage tanks to allow for future settlement.

M. Except at valves and line terminations, the use of flanges shall be avoided.

IX. FABRICATION

A. Fabrication shall be in accordance with JOB SPEC 4478-52A1.

B. Jet-Lube TF-25 (max. service temp. 315°C) shall be used as a thread sealer in threaded lines, including vents and drains. Where thread sealer is prohibited, threaded connections shall be made with no thread compound and shall be seal welded.

X. EXAMINATION AND INSPECTION

A. Process Piping

1. The type and extent of examination shall be as required by Job Spec 4478-52A1.

B. Boiler Piping

Boiler piping, including Boiler External Piping, shall be inspected during construction and after completion by an ASME Code Inspector, who will approve stamping the fabricated sections and complete Form P-4A. This will be forwarded to the Purchaser to become part of the Master Data Report.

JOB SPEC 4478-50A1 PIPING PAGE 44 REV 7 DATE Apr 12, 1999 XI. CLEANING

A. Piping and Equipment

The internal cleaning and flushing of piping and equipment prior to start-up shall be in accordance with specifications related to plant completion. Plant Completion Specification is not within the scope of Basic Engineering design at present.

B. Compressor Piping

The following shall be cleaned in accordance with JOB SPEC 4478-50A6:

1. External systems circulating lube oil and seal oil for

centrifugal compressors and turbo-generators.

2. Suction and interstage piping and pulsation dampers. XII. TESTING

A. Field pressure testing of the piping shall be performed in accordance with JOB SPEC 4478-89A1 and the applicable code.

B. Shop fabricated piping other than boiler piping shall not be

pressure tested by the shop unless specified in the Requisition. XIII. COATING

A. Aboveground piping shall be painted in accordance with JOB SPEC 4478-83A1. Underground steel piping shall be coated and wrapped in accordance with JOB SPEC 4478-83A4.

B. Lead and zinc compounds shall not be permitted to contact

austenitic stainless steel pipe and piping components at any temperature. The use of paints containing lead and zinc shall be prohibited.

JOB SPEC 4478-50A1 PIPING PAGE 45 REV 7 DATE Apr 12, 1999 R:\COMMON\JUP\SPECS\JS50A1.doc\lf

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