VESBI002 Design and Specification of Vessels for Bulk Solids

8/9/2019 VESBI002 Design and Specification of Vessels for Bulk Solids

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Process Industry Practices

Vessels

PIP VESBI002Design and Specificatio

Vessels for Bulk Solid


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Process Industry Practices

Vessels

PIP VESBI002

Design and SpecificatioVessels for Bulk Solid

Table of Contents

1. Introduction..................................31.1 Purpose ............................................. 31.2 Scope.................................................31.3 Alternative Design Proposals............. 4

2. References ...................................42.1 Process Industry Practices ................ 42.2 Industry Codes and Standards .......... 52.3 Other Codes ...................................... 62.4 Other References .............................. 62.5 Government Regulations................... 7

3. Definitions ....................................7

4. General .........................................84.1 Applicable PIP Documents ................ 84.2 Exemptions........................................84.3 Jurisdictional Compliance.................. 94 4 Units of Measurement 9

4.11 DocumSuppli

5. Selection

Guidelin5.1 Solids5.2 Flow R5.3 Cylind

Select5.4 Bottom5.5 Discha5.6 Fluidiz5.7 Bin Ins

5.8 Blende5.9 Interna5.10 Suppo5.11 Metho

Bulk S5.12 Materi5.13 Pressu


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PIP VESBI002Design and Specification of Vessels for Bulk Solids

6.6 Design Loads and Load

Combinations ...................................266.7 Vessel Support Systems..................346.8 Top Head..........................................366.9 Shell .................................................376.10 Bottom..............................................376.11 Shell-to-Bottom Joint (Skirt Ring).....386.12 Vessel Connections..........................386.13 Gaskets............................................416.14 Internal Components........................426.15 Corrosion Allowance ........................426.16 Compartment Vessels......................426.17 Minimum Thickness .........................426.18 Anchor Bolting..................................436.19 Lifting Lugs .......................................436.20 Structural..........................................44

7. Materials......................................447.1 Allowable Stress Values...................447.2 Carbon Steel ....................................44

7.3 Stainless Steel..................................447.4 Clad Material ....................................447.5 Prohibited Materials..........................45

8. Fabrication..................................458.1 General.............................................458.2 Welding ............................................458.3 Flanges.............................................468.4 Prohibited Construction ....................47

8.5 Tolerances .......................................478.6 Linings ..............................................47

9. Inspection and Testing ..............499.1 Inspection.........................................499.2 Testing, General...............................50

10. Shipping....................................5110.1 General.............................................51

10.2 Cleaning and Painting ......................5210.3 Preparation for Shipment .................52

11.Instrumentation.........................5311.1 General.............................................5311.2 Side-Entry Instrumentation...............53

12 N l t d St i 53

APPENDIX A - Plan for Ves

APPENDIX B -

Schedule a

Package

APPENDIX C- F

Boundary J

APPENDIX D -

Information

APPENDIX E -

Formulas fo

and Axial T

APPENDIX F -


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July 2001 Design and Spe

1. Introduction

1.1 Purpose

This Practice describes the materials, design, fabricat

documentation requirements for the construction of a

welded, shop- and field-fabricated dry bulk solids bin

blenders for various chemical facilities. These bulk so

blenders generally meet the philosophy and requirem

of theASME Boiler and Pressure Vessel Code, hencehowever, Codeinspection and stamping are not requi

1.2 Scope

In addition to any limitations stated in this Practice, th

not address the following:

Mechanically fastened shell or head courses wi

Non-metallic material requirements, including

Design and fabrication of fluidized beds

Design and fabrication of non-cylindrical shells

Requirements associated with vessels mechanicblade impellers

Portable transport containers

1.2.1 This Practice designates requirements for the

welded, cylindrical shell, single-wall vessels

pressures not exceeding 15 psig and/or full v

top of the vessel in its normal operating posit

is required to define options covered herein a

applicable to the particular vessel under cons

normal operation, upset, shutdown), location

1.2.2 For bulk solids vessels having internal and/orthe 15-psig limit, use this Practice for solids-h

PIP VECV1001,PIP VESV1002, andPIP VE

issues.

1.2.3 Unless approved by Purchaser, this Practice i

containing lethal substances defined as poi


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applications of low-pressure vessels, these practic

sound engineering judgment and supplemented arequirements related to specific materials of cons

operating environments, and vessel geometry. Ac

understood that provisions of this document may

supplemented by an overlay specification. (See S

1.2.5 The intent of this Practice is to provide enough in

construct a complete vessel. Any part necessary t

shall be provided by the Supplier. The equipment

responsible for any licensing and licensing fees afabrication, and/or use of the equipment. Any aux

are to be identified in the bid and included in the

1.3 Alternative Design Proposals

The base bid shall be provided in full compliance with th

alternative design may be submitted if economy and/or im

realized without reducing the capability or shortening the

vessel. The following requirements must be met when sub

a. Alternative design quotations shall be accompanied

be clearly noted as an alternative.

b. Alternative designs shall be fully and clearly descri

sketches or drawings. Specific exceptions shall be i

c. An alternative design shall not be used unless appro

2. References

The documents listed in this section are only those specifically re

Laws or regulations issued by any applicable local, county, state,

covering low-pressure vessels shall be reviewed before the initiat

the requirements may be different or more restrictive than the req

Practice.

2.1 Process Industry Practices (PIP)

The latest edition issued at the date of the contract award

PIP CTSE1000 -Application of External Coatings

PIP VECV1001 - Vessel/S&T Heat Exchanger Des

Section VIII, Divisions 1 and 2


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American Society of Civil Engineers (ASCE)

ASCE 7 -Minimum Design Loads for Buildings an

Standard Association of Australia

AS 3774 and Supplements 1 and 2 -Loads on Bulk

British Standards Institute and the British Materials H

Silos: Draft Design Code for Silos, Bins, Bunkers, a

Deutsches Institut fur Normung (DIN)

DIN 1055, Part 6 -Design Loads for Buildings, Loa

Standard]

International Conference of Building Officials (ICBO)

Uniform Building Code (UBC)

Manufacturers Standardization Society (MSS)

MSS SP-6 - Standard Finishes for Contact Faces of

Connecting End Flanges of Valves and Fittings

National Association of Corrosion Engineers (NACE)

NACE RP0178 - Standard Recommended Practice

Surface Finish Requirements and Proper Design C

Vessels to Be Lined for Immersion Service

National Fire Protection Association (NFPA)

NFPA 68 - Guide for Venting and Deflagrations

NFPA 69 - Standard on Explosion Prevention Syste

Welding Research Council (WRC)

WRC Bulletin 107 -Local Stresses in Spherical an

External Loads

WRC Bulletin 297 -Local Stresses in Nozzles in Sp

Shells Due to External Loads (A supplement to WR

2.3 Other Codes

Requirements for solids vessels, constructed in accordanc

those specified in the ASMEPressure Vessel Codein Sec

agreement between Purchaser and Supplier(s).


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Buzek, J. R., Useful Information on the Design

American Iron and Steel Institute and Steel Pla1989

Galletly, G. D.,Design Equations for Preventin

Torispherical Shells Subjected to Internal Pres

Mechanical Engineers, London, Vol. 200, No A

Process Equipment Design, Brownell and Youn

1959

Jenike, A. W., Johanson, J. R., and Carson, J. W

Industry, Transaction ASME, Series B Vol. 95,

Vellozzi, Joseph,Dynamic Response to Wind L

2.5 Government Regulations

U.S. Environmental Protection Agency (EPA)

Clean Air Act Amendments of 1990

U.S. Department of Labor, Occupational Safety an(OSHA)

OSHA 29 CFR 1910.106(b)(5)(ii) -Flammable

OSHA 29 CFR 1910.119 -Process Safety Man

Chemicals

OSHA 29 CFR 1910.146, (K)(3)(ii) -Permit-R

General Industry

3. Definitions

For the purposes of this Practice, the following definitions ap

Angle of Repose (Poured): The slope of the surface of bulk so

pouring solids onto a horizontal plane. The angle is measured

angle is not a flow property.

Angle of Repose (Drained): The slope of the top surface of budischarging a container that holds the bulk solid. This angle is

Arching: A no-flow condition in which the bulk solid forms a

Typically, this arch forms at the bottom outlet opening, but m

the hopper or bin. At a sufficiently large discharge opening, a

sustained The terms bridge and dome are also used to de


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Construction: An all-inclusive term comprising materials, design,

inspection, and testing

Designer: The party responsible for defining and specifying the m

requirements consistent with the User criteria for use by the Supp

typically an engineering contractor but could be the User, Purchas

or the Supplier(s).

Fabrication: The actual making and assembling of the vessel and

specified materials and in accordance with the purchase order

Fluidization: The use of gas flow to permeate the interstitial spac

some bulk solids act more like a liquid

Operating Load: Includes the weight of the stored product, based

density of the product, and internal pressure, if any

Overlay Specification: Technical requirements that supplement or

this document, such as a User Specification or a project specificat

Purchaser: The party actually placing the order with the Supplier

components and can also be the Designer. The Purchaser is requir

requirements are fulfilled. The User may be the User or the User

Supplier: The party entering into a contract with the Purchaser to

accordance with the purchase order

User: The party responsible for establishing construction criteria

philosophy and service hazards of this Practice as described in SeUser refers to the owner and/or operator of the equipment.

User Specification: A term that shall be understood to include any

or service-specific data designated by the Purchaser for a particul

silo, or blender or group of such. SeePIP VEDBI003for data she

Vessel: A non-specific reference to a bulk solids bin, hopper, silo

4. General

4.1 Applicable PIP Documents

All vessels shall be designed in accordance with this Prac

standard details specified in Section 2 and with other stan


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4.3 Jurisdictional Compliance

4.3.1 All aspects of the work shall comply with anyand federal rules and regulations, including b

standards established by EPA and OSHA, if a

4.3.2 Site-specific laws, rules, and regulations shal

and shall be noted on data sheets, in engineer

specifications.

4.3.3 It is acceptable to replace all references to EP

national equivalent applies at the site.

4.4 Units of Measurement

U.S. customary (English) units shall be regarded as st

be included for reference only and shall not be interp

4.5 Language

All documents shall either be in English or shall show

4.6 Purchasers Responsibilities

The Purchaser shall furnish a User Specification, whi

operating conditions of the vessel to provide a basis f

User Specification shall also identify the external env

exposed, the intended function of the vessel, the mech

vessel, the specific installation requirements, and the

applicable where the vessel will be installed.

4.6.1 The Purchaser shall provide the minimum an

the product. The values of the minimum and m

be shown on data sheets, sketches, or drawing

Specification.

4.6.2 The strength and flow properties of the conta

by the Purchaser and shall be determined by

of the product.

4.7 Suppliers Responsibilities

4.7.1 The Supplier is responsible for the constructi

silos and associated chutes; supports; and inte

identified in or required by this Practice and t

herein. Review by the Purchaser or User of d


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4.7.2 The Supplier shall guarantee that the equipment s

under the conditions specified by this Practice anherein, shall maintain structural integrity and mee

structural requirements outlined in these documen

order.

4.7.3 Bins, hoppers, and silos and associated chutes, su

assemblies shall be identified and labeled in acco

designations.

4.7.4 Any alternative design(s) shall not be used unless

Purchaser.

4.7.5 Subcontracted fabrication work: Approval must b

before any welding or preparation for welding is

shop or Supplier. Such approval shall require kno

qualifications of the subcontractor who is perform

Supplier(s) retains accountability for the subcont

4.8 Disclaimers

4.8.1 Specified design: When a vessel or vessel compo

the Purchasers data sheets, sketches, or drawings

way relieved of obligations and/or responsibilitie

purchase specifications.

4.8.2 Welding: Welded fabrication shall not be sublet w

the Purchaser.

4.8.3 Inspection: Release for shipment by Purchasers o

relieve the Supplier(s) of any responsibility for co

specifications and/or drawings.

4.9 Conflicts

If a conflict is identified between this Specification, the d

sheet, referenced codes and standards, or any supplement

having identified the conflict shall obtain written clarifica

before proceeding with any work.

4.10 Documentation Provided by the Purchaser

The following information shall be provided with the pur

4.10.1 Completed data sheetPIP VEDBI003with additi

as necessary


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4.11 Documentation Provided by Supplier

The following information shall be provided to the Pudocumentation provided in accordance with the purch

Documentation Schedule in Appendix B.

4.11.1 Any deviation from these specifications intro

indicated in the original quotation as an excep

4.11.2 Alternative design quotations shall be accom

and shall be clearly noted as an alternative de

4.11.3 Alternative designs shall be fully and clearly sketches or drawings. Specific exceptions to

Practice shall be identified as such.

4.11.4 Reproducible materials shall be of suitable qu

scanned (ANSI/AIIM MS32).

4.11.5 Instructions shall be provided for removal of

materials used for protection during shipmen

4.11.6 Fabrication drawings shall be in accordance w

Drawing Information.

4.11.7 Design calculations shall include references t

formulas and calculated results. For a compu

calculations, a program description shall be g

name and version. If the program is not comm

program documentation shall be maintained a

request.

Design calculations associated with all comp

including but not limited to the following:

Wind and seismic, as applicable

Support(s)

Lifting and erection of the vessel

Nozzle load(s) analysis for local and gr Design of internal and external attachm

Specified design loads and load combin

Fatigue analyses as applicable for fatig

i l d i d d b h i l


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Requirements for providing the fabrication data p

shall be specified by the Purchaser in the purchas

5. Selection and Design Guidelines

This section provides guidelines and other tutorial information int

Designer in selecting and specifying bulk solids bins, silos, hoppe

5.1 Solids Flow Properties

5.1.1 It is important to ascertain properly the solids flowhen designing a bin, hopper, silo, or gravity blen

should be considered when designing a vessel for

follows:

Arching and rathole critical dimensions (coASTM D6128)

Mass flow critical wall angle (Wall Friction

Bulk density variation (compressibility test

Flow rate limitations (permeability tests)

Minimum angle of chute for reliable flow (

Gas quantity and pressure for effective flui

Independent laboratories may perform these tests

be purchased and the tests performed by the Purc

Certain material and/or environmental conditions

above-listed tests. It is important that the followin

considered and that tests are run over the comple

that are expected in the solids-handling process:

Temperature

Pressure

Mechanical overpressure

Moisture

Consolidation (storage) time

Particle size


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5.2 Flow Regimes

Graphical representations of the four major symmetriFigure1. Descriptions of each of these flow regimes f

describes the flow pattern achieved from a center-disc

obstructions exist that might cause preferential flow f

from one side of the vessel. This Practice covers only

for solids.

Off-center or side-discharge outlets will cause eccent

flow patterns can also be caused by improper dischar

eccentric flow patterns may be induced by improperlyequipment, such as non-mass flow screw feeders, and

valves. The effects of eccentric flow patterns on struc

implementation of proper discharge practices to ensur

flow is required, it is important to perform proper ana

design can accommodate loads created by eccentric f


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Flow Zone

Type 1

Mass Flow

Flow Along Walls

Type 3

Rathole

(Pipe Flow)

Secondary Flow Zone

Secondary F


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5.2.1 Description of Mass Flow (Type 1, Fig

Mass flow is characterized by having no stagdischarges from the vessel. A mass flow patte

in, first-out flow from the vessel. However so

the wall, which will hinder the ability to obta

bins generally have uniform discharge rates w

consistent bulk densities. Mass flow ensures

vessel, and it promotes de-aeration of the pro

combination of a sufficiently steep hopper an

walls. Marginal designs may lead to slip-stickbe unsteady. Slip-stick flow may lead to indu

severe at times.

Discharge outlets for mass flow hoppers mus

The geometry of the hopper must create stres

overcomes the strength of the product, thus b

Minimum outlet diameters for prevention of a

may be determined only by testing the produc

according toASTMD6128.

5.2.2 Description of Funnel Flow (Type 2, Fi

A dynamic product flow channel surrounded

characterizes funnel flow. This flow pattern i

of an insufficient hopper angle and insufficie

discharge outlet that is not fully effective.

The latter situation can be caused by imprope

the discharge line, partly closed valves, poorlequipment, etc. Funnel flow is generally acce

materials that do not require first-in, first-out

can be problematic for the following:

Fluidizable materials where preferentia

Materials where segregation is a conce

Cohesive materials where arching and r

Products that require first-in, first-out f

Products that degrade over time

Situations where dependable control ov

Discharge outlet diameters for funnel flow ho


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material (thus the name rathole) from the disch

vessel through which new material placed in the vstagnant material may significantly reduce the eff

vessel. Ratholes may be avoided by designing the

to overcome the internal strength of the product b

5.2.4 Description of Expanded Flow (Type 4, Fig

Expanded flow is a combination of mass flow and

by mass flow in the hopper section and funnel flo

This design aids in the prevention of rathole deve

by allowing for a switch to a mass flow hopper atminimum rathole diameter for the product being s

particularly useful in multiple hopper outlets, wh

placed next to one another to create a combined f

than the minimum rathole diameter.

5.3 Cylindrical Versus Polygonal Selections

Cylindrical shell designs are generally favored be

higher pressure rating at a lower cost than can porequire extra reinforcement for corners and flat si

easily achievable in cylindrical vessels because o

restrictions in the cylindrical design.

Polygonal designs are best used in applications fo

desirable, headroom is a concern, and low operat

This Practice addresses only the design and fabric

designs.

5.4 Bottom Hopper Selection

Various types of bottom hoppers may be used on cylindri

should be taken in selecting the type of bottom hopper to

fits the application.

5.4.1 Conical Center-Discharge

A conical hopper with a center discharge is a stanhopper design to which many types of feeders are

hoppers may also be designed with dual angles (a

to inlet varies) and with eccentric outlets. Design

includes the following:

Walls must be sufficiently smooth


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5.4.2 Flat Bottom

Flat bottoms are generally a good choice for cfluidized blending and/or discharging will be

storage vessels where complete emptying is n

bottom vessel for mass flow applications is o

size of the feeder required. Design to achieve

following:

Walls must be sufficiently smooth.

The outlet diameter must equal the cyli Discharge from the outlet must be unifo

outlet.

The outlet diameter (and thus the cylinlarger than the minimum arching diame

5.4.3 Chisel (Wedge)

A chisel hopper has a slotted discharge outlet

diameter of the cylindrical shell. The slotted

for example, auger, screw, and belt feeders. W

hoppers as described below) may be advantag

hopper for the following reasons:

Less steep hopper angles (10to 12leand still have mass flow, which is more

Smaller outlet sizes (one-half the diam

is necessary for flow; thus, cones typicexpensive feeders)

Higher flow rates

Less headroom required (important in r

Capital cost that may favor a wedge or the situation (consider less expensive h

more expensive feeder and gate)

The design of a wedge hopper may require m

does the standard cone design. Design to achi

following:



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The outlet width must be larger than the mi

given application. The length of the discharge opening must b

width of the discharge opening.

5.4.4 Transition Hoppers

A transition hopper is used for the change from a

slotted discharge outlet. The slotted outlet is suita

screw, and belt feeders as examples. (See above c

transition hoppers to conical hoppers.) The designdepth load analysis than does the standard cone d

mass flow includes the following:


The hopper end-wall angle must be steeperhopper angle for mass flow for a given app

The hopper side-wall angle must be steeper

angle for mass flow for a given application

The discharge outlet width must be greater width.

The discharge outlet length must be three tidischarge outlet width.

Discharge from the outlet must be uniform outlet.

5.4.5 Multiple Dischargers

Hoppers with more than one outlet may be design

depending on the particular need. Design to achie

following:


The discharge outlet width must be greater

width.

The hopper end-wall angle must be steeperhopper angle for mass flow for a given app

The hopper side-wall angle must be steeperangle for mass flow for a given application


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Discharge from the outlets must be uni

outlets, and material must be drawn fro

5.5 Discharge Aids

Discharge aids are used to promote flow of bulk solid

characteristics such that none of the bulk solid flows

bulk solids flows at rates less than required. The follo

5.5.1 Fluidization and aeration devices - These dev

where gas easily permeates interstitial spaces

internal cohesive forces and wall friction forcFluidization is effective in promoting flow an

a vessel holding fluidizable material. Fluidiza

into a vessel or can often be retrofit into an ex

aeration may be introduced through nozzles o

internal fluidizing media (for example, perfor

5.5.2 Agitation - Agitation is effective on many typ

used to mechanically assist material flow. Scr

promote and meter flow simultaneously. Propto ensure uniform solids flow is critical when

bin. Caution must be used when considering

fluidize easily (the material may flush throug

or that have a low melting temperature (heat m

bearings, etc.) Wear, maintenance, and powe

concern with these devices.

5.5.3 Compressed gas devices (air cannons or air b

or nitrogen) is often used as a means to create

shock wave acts over a localized area and is i

stresses that enable a stable arch or rathole to

may be seen when using air cannons on ratho

only localized areas can be cleared. Best resu

size, number, and placement of air cannons a

using these devices, consideration must be gi

localized pressure zones created in the vessel

compressed gas. Consideration must also be gvessel wall, especially with aluminum vessels

5.5.4 Sonic horn - Similar to compressed gas devic

waves to promote material movement.

5.5.5 Vibration devices - Air-driven or electric-driv


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5.5.6 Vibrating and oscillating dischargers - Vibrating

use vibration in either a vertical or horizontal dire

a vessel. Consideration should be given to dead lo

effects on the vessel to discharger interface. Thes

appropriate for pressure-sensitive materials or in

flow is needed or segregation is not acceptable. O

either internal cones or internal plates or screens

Maintenance of vibrating and oscillating discharg

the vessel has to be emptied to replace some com

5.5.7 Forced extraction - Mechanical devices are used along a vessel wall or bottom, toward the dischar

inside the vessel and may or may not be covered b

operates. Consideration should be given to mainte

consumption, and deformation and wear of the de

5.5.8 Flexible wall - Flexible walls in a hopper allow f

in a material that would normally build, thus prom

can be used in conjunction with external mechani

the flexible wall, thus agitating the material. In thmust be taken not to overly compact the material.

flexible wall hopper is of concern because of the

inaccessibility of the liner if it fails while in use.

5.5.9 Chemical flow aids - Chemical flow aids may be

enhance flow properties. Chemical flow aids typi

physically separating particles, (2) competing for

canceling electrostatic charges/molecular forces,

lattices.

5.6 Fluidized Material

In designing for fluidization in general, the following item

Permeability of the solid to be fluidized (i.e., fluidizmaterial of concern)

Stresses on the bin from both fluidized and non-flu

and discharged from the bin

Design of the vessel and/or its relief devices to meepressure from the gas header

Design of the vessel and/or its discharge devices anmeet required gas flow and its discharge from the v


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5.7.2 The design of the bin insert must account for

product that the insert will experience in both

5.7.3 Bin inserts must be designed to avoid ledges

hinder or block product flow.

5.7.4 All parts on the insert that come in contact w

compatible with the product.

5.7.5 The design of the vessel and connection mem

flanges, welds, etc.) must account for the dea

as any live loads or fatigue loads created by ubottoms).

5.8 Blender Selection

Many types of blenders are available for various appl

continuous blending to small-scale, batch blending. T

blending applications that utilize vessels in the blend

5.8.1 Gravity Tube Blenders

In a gravity tube blend vessel, product is sam

the vessel bed through the use of internal or e

each of the tubes is mixed in a blend chambe

and blended product is discharged from the b

If internal tubes are used, the tubes are run ve

vessel (the tubes may penetrate the vessel wa

externally). Each tube has inlets (usually mul

along the tube length) through which productcarried to the blending chamber at the bottom

Gravity tube blend vessels are generallpelletized materials.

Ensure that blend tube design provides

Ensure that the vessel wall thickness ansupports are adequate for the eccentric

material into the blend tubes.

5.8.2 Velocity Gradient Gravity Blenders

A velocity gradient gravity blender mixes ma

velocities within the flow channel. In simple

residence time in the blender flows at a faster


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and fluidized blenders. This Practice does not cov

considerations related to these types of blenders a

5.9 Internals Design Guidelines

5.9.1 Consideration shall be given to the following forc

supports, blend tubes, etc.:

Increased radial forces from product flow (circumferential stresses) produced by any c

area, such as the presence of internal cones

bottom transitions

Lateral forces produced from product flow by the presence of a gravity blend tube syst

impact both the system and the system-to-s

Consideration shall be given to provide add

tube-to-wall intersection and blend tube sup

Shear forces produced from eccentric outle

within a vessel having one or more eccentrmembers and member support designs need

additional shear force(s) produced from pro

outlets.

5.9.2 Avoid areas on internal components that allow pr

Specifically, the top edges of supports need to be

flow of material around supports, and areas wher

cone need to have a sloped deflector on the upstre

and the cone. See Figure F-1 in Appendix F.

5.9.3 Be cautious of effects of internal components on

versus funnel flow) or flow reliability (bridging, r

5.9.4 Avoid moving parts or other maintenance items w

that these parts may need to be repaired at inoppo

when the vessel is full of solids.

5.9.5 Be aware of cleaning needs when designing (for

access to blend tube interior walls for cleaning).

5.9.6 Consideration shall be given to the design of non

penetration points. It is especially important to co

applications such as seals where movable interna

externally.


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5.11 Methods for Determining Bulk Solids Design

5.11.1 Several methods for determining stress profilare acceptable for determining stress values t

vessels. Acceptable methods for determining

found inDIN 1055,AS 3774, A.W. Jenike, et

Journal for Industry), andBritish Standards I

Materials Handling Board.

5.11.2 A comparison of these methods can be found

5.12 Materials

The Designer shall select materials, coatings, liners, a

tested with the contained product to determine which

product and shall identify these choices in data sheets

5.13 Pressure Venting and Relief

A means of venting gas (into and out of the vessel) un

conditions must be included in the design of the vesse

relieving pressure under abnormal operating conditio

Venting gases under normal operating conditions can

depending on the application. Regardless of the mean

must consider situations, whether intentional or induc

into or out of the vessel. Some examples of situations

include:

Gas displaced while filling a vessel

Gas required to fill void spaces when dischargi

Gas introduced into a vessel by gas cannons, aevents, fluidization media, gas purges, etc.

Gas introduced and gas displaced when pneuma vessel

Leakage gas on valves attached to the vessel (e

Gas flow induced by temperature changes insidtemperature changes outside the vessel)

Condensation of vapor or vaporization of liquidduring cleaning

F i f ti ti f d fl ti (


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6. Design

6.1 Geometric Configurations

6.1.1 The design volume and equipment dimensions sh

storage capacity and the minimum bulk density o

6.1.2 When the geometric configuration and critical dim

by the Purchaser, the Designer shall ascertain the

properties of the bulk solid to be contained by the

shall be the properties at the worst-case condition

practice. This shall include factors such as the mi

highest moisture content, temperature range, and

rest.

6.1.3 Where the contained product is a well-known com

known flow characteristics, the User may choose

configuration and critical dimensions on the basis

with that product.

6.1.4 Where the discharge opening must be much largeratholing) than is required to attain the desired di

feeder to control flow without affecting the desire

The Designer shall select a hopper configuration

discharge shape and dimensions in conjunction w

device, subject to the Users approval.

6.1.5 When the geometric configuration and critical dim

provided by the User, the Designer shall assure th

sustain the loads caused by internal and external fof the bin, hopper, or silo walls.

6.2 Design Pressure and Temperature

6.2.1 The design pressure (internal and external) and c

temperature shall be determined by the Designer,

operating phases that the bin, silo, hopper, or blen

the specified project life, such as the following:

Initial startup

Normal operations

Temporary operations

Emergency shutdown


27/73


Upset conditions

Environmental restraints on relief venti

6.2.2 The maximum and minimum operating pressu

Pressures and Temperatures) shall be specifie

6.3 MAWP and Coincident Maximum Temperatur

The maximum allowable working pressure (MAWP)

marked on the nameplate is defined as the maximum

the top of the completed vessel in its normal operatin

designated coincident maximum design temperature f

shall be determined from calculations based on the sp

thickness (but reduced by any specified liner thicknes

6.3.1 Purchaser-specified Design Pressures (interna

After selecting a design that meets these Desi

(internal and external) that can be obtained w

and geometry selected at the maximum design

corroded condition shall be determined. CalcMAWP (internal and external). The vessel na

indicate the MAWP (internal and external). T

drawing(s) shall clearly indicate the compone

(internal and external). The vessel drawing(s)

required thickness for MAWP of the top head

6.3.1.1 The external MAWP shall be provide

requested by the Purchaser.

6.3.1.2 Code-required stiffening rings for sheshall be placed on the outside of the v

than 3/8 inch, and have a ring width-

than 10. Stiffening rings shall be atta

UG-30).

6.3.2 See Codeparagraph UG-20(a) for rules relati

coincident maximum Design Temperature to

A suitable margin consistent with the uncerta

maximum mean metal temperature can be de

maximum design temperature rating shall be

temperature possible without affecting the th

without changing the pressure class for the no

design temperature shall not be less than 150

PIP VESBI002


28/73


6.3.5 The vessel shall be designed so that any compone

will withstand the test conditions defined in Secti

the allowable stress levels defined in CodeSectio

6.4 Minimum Design Metal Temperature (MDMT) and

6.4.1 The MDMT and coincident pressure to be marke

selected by the Designer in consideration of the o

those listed in Section 6.1 of this Practice and of t

UG-20(b). The minimum design temperature sha

Specification. When ambient temperatures gov

startup or normal operations, the lowest 1-day me

the installation site shall be the MDMT value pro

exceed 30F. Figure 2-2 ofAPI 650shall be used1-day mean temperature insofar as applicable. Th

during shop and future field pressure testing shall

the vessel design stage. During the pressure test, t

components and attachments that, when welded t

components are judged to be essential to the vess

shall have a temperature not less than the MDMTnameplate.

6.4.2 The MAWP shall be based on the maximum desi

not be limited by the MDMT. The MAWP shall b

nameplate and vessel drawing(s).

6.5 Venting and Relief Protection

6.5.1 Vessel vent systems shall be sized such that the Mvacuum (external pressure), and the relief protect

exceeded.

6.5.2 All vessels shall be provided with relief protectio

and vacuum.

6.5.3 Actions of the relief device shall not exceed the M

and vacuum) rating of the vessel.

6.5.4 NFPA 68andNFPA 69shall be used in sizing deand for selecting explosion prevention systems w

6.5.5 If deflagration is possible, it must be incorporated

Section 6.6.3 of this Practice. See Codeparagraph

6 6 Design Loads and Load Combinations


29/73


6.6.2 Operating Load (L2)

Operating load is the weight of the bulk solidlevel, including that on or in any vessel intern

weight of the contained product shall be calcu

equipment dimensions, the angle of repose of

maximum bulk density of the contained produ

bridged (arched) product could impact the

structure, the equipment shall be able to susta

6.6.2.1 Impact loads resulting from collapse

separately from the operating load.

6.6.2.2. Impact loads are additive to the equip

seismic loads shall not be considered

loads.

6.6.3 Pressure Load (L3)

Pressure load is the MAWP (internal or exter

temperature), including the pressure drop thro

with more than one independent chamber, se

6.6.3.1 Where fluidization is a possibility, th

hydrostatic pressures caused by the c

computation of pressures shall be bas

head of the product.

6.6.3.2 Overpressure situations, such as defl

pressure testing, etc., must be consid

6.6.4 Thermal Load (L4)

Thermal loads are forces caused by the restra

expansion/interaction of the vessel and/or its

6.6.5 Wind Load (L5)

User selections are fromASCE 7 (citations ar

otherwise specified).

Note:Local codes or regulations may requother rules for wind load design.

Wind load design requirements that shall be u

covered inASCE 7; however, simply specifyi

withASCE 7is an incomplete specification b

ASCE 7 that the Designer must make The ve

PIP VESBI002


30/73


account for wind-induced forces on common app

as these.ASCE(ISBN-0-7844-0262-0) provides g

determining the total wind-induced forces on ves

appurtenances. The Detailed Method described in

used for the vessel design when such appurtenanc

The Designer shall determine and specify on the

the following items:

6.6.5.1 Classification Category (from ASCE 7-

There are four classification categories. T

Designer to determine the Importance Fa

ASCE 7-95. The Importance Factor is nee

velocity pressure. Category II (formerly C

ASCE 7editions) has been the industry st

cases it may be appropriate to select the c

6.6.5.2 Basic Wind Speed (from ASCE 7-95 Ta

The Designer shall make basic wind spee

the geographic location of the equipmentDifferent units of measurement for wind

for design. The basic wind speed inASCE

second gust. This is the mean wind speed

All American codes written beforeASCE

terms of the fastest mile. These wind spee

interchangeably in design. Interchanging

can produce results that may be 40% or m

6.6.5.3 Exposure Category (from ASCE 7-95 P

There are four Exposure Categories from

pressure coefficients, Kz, are provided in

the selected Exposure Category. Exposur

selected for most Gulf Coast sites. For no

Exposure Category B is often selected. T

determination relevant to the geographic

point of installation.

6.6.5.4 Topographic Factor, Kzt (from ASCE 7-

Figure 6-2)

Wind speed-up over isolated hills and esc

considered for Exposure Category B, C, o

terrain is free of such topographic feature


31/73


6.6.5.5 Gust Response Factor, Gf

For flexible structures such as a tall vresponse factor, Gf,is another essenti

the wind forces involved. The instruc

regard are as follows:

Gust response factors for maof flexible buildings and othe

by a rational analysis that inc

properties of the main wind-

For flexible vertical vessels, fundamental (natural) freque

1 hertz (including vessels wit

ratio greater than 4, where h

and D is the vessel diameter

of the vessel wall), the recom

determined using either the a

paragraph 6.6 of the Comme

some other rational analysis mdynamic properties of the ma

When employing equation C

paragraph 6.6, use 0.01 as th

construction.

6.6.5.6 Force Coefficients

Force coefficients, Cf, formerly calle

needed to determine wind-induced foTypical factors are provided inASCE

are recommendations for Cf to be use

Condition

A. For all horizontal vessels and for vervessels having a h/D ratio not greatethan 1

B. For vertical vessels having a h/D rat

greater than 1 (applies to height ofvessel without spoilers)

C. For portion of height of vertical vesseprovided with spoilers as recommenSection 6.5.5.7.2 of this Practice

PIP VESBI002


32/73

Design and Specification of Vessels for Bulk Solids

with the undesirable predominant frequen

addition of spoilers is typically more feas

natural frequency of the vessel or provididamping.) In the case of cylindrical press

determined to be candidates for wind-ind

found that spoilers are only required for t

height and that normal attachments in thi

piping) will be effective as spoilers provi

circumferential distance between them is

vessel circumference).

Vessels with an h/D ratio of 15 or greater

significant number of effective attachmen

dynamic behavior from wind excitation a

6.6.5.7.1 Vortex-shedding ranges - Vess

three vortex-shedding ranges:

Lower periodic vortex-shReynolds number is less

Strouhal number is appro

caused by periodic vortex

tall, slender vessels that h

frequencies.

Random vortex-sheddingnumber is between 300,0

vortex shedding occurs. I

approximately 0.2, the ramay lock-in and become

to vibrate.

Upper periodic vortex-shReynolds number is high

Strouhal number is appro

vibration will occur when

the vessel corresponds w

shedding.

6.6.5.7.2 Corrective action - When it has

vessel may vibrate and the attri

normal attachments) cannot be

vibration will not occur, wind s


33/73


the top. The spoiler s

provide clearance at

Short vertical spoilershort vertical spoiler

on the top third of th

beyond insulation of

and the pitch (height

5D and 11D. There s

spoilers over the pitc

helical wrap) and a m

helical wraps over th

spoiler system may b

clearance at vessel ap

Projected area: Whenshort vertical spoiler

area normal to wind,

coefficient, Cf, for th

have been added shavessel and supportin

overturning load. Th

calculated using the p

outside edge of the sp

of the section under c

6.6.6 Seismic Loads (L6)

General requirements and data are fromASCE

specified.

Note:Local codes or regulations may requ

other rules for seismic design.

The seismic design requirements and the spec

for the calculation of seismic response loads

ASCE 7. The calculation of seismic forces for

two methods: vessels mounted on the ground

grade within a structure.

The first step in an analysis is to perform an e

to calculate its first natural period (horizontal

position). This is done by dividing the vessel

mass and stiffness elements per the theory of

PIP VESBI002D i d S ifi ti f V l f B lk S lid


34/73


6.6.6.1 Seismic Loads for Ground-Supported

The governing equation for horizontal sesupported equipment is V = CsW, where

Cs= 1.2AvS/0.66RT.

However, CS (seismic design coefficient

5.5Aa/R. (Av, Aa, S, and R are site-speci

natural period of the equipment to be calc

W is the operating weight of the equipme

The lateral horizontal seismic forces indupoints of the equipment and in the directi

stresses shall be determined from the rule

6.6.6.2 Seismic Loads for Structure-Mounted

For equipment mounted in a structure abo

equation for seismic force is FP= AvCcPa

Av= (a site-specific value)

Cc(equipment seismic coefficient) = 5.

P (performance criteria factor) = 1.0

ac= 1.0, except for flexible equipment

and vessels on tall legs, springs, or o

factor is then given as ac= 1.0 for T

ac= 1.0 for Tc/T < 0.6 or Tc/T > 1.4

natural period of the equipment, and

of the structure.

Wcis the operating weight of the equipm

Fpis the horizontal seismic force applied

the equipment and in the direction causin

6.6.6.3. Seismic Documentation

The Designer shall specify requirements

site-specific design values on data sheetPspecified, the vessel and vessel supports

seismic effects, and evidence shall be pro

vessel and vessel supports satisfy applica

Satisfactory evidence shall be design calc

documented proof of compliance. Seismi



35/73


6.6.8 Piping and Superimposed Equipment

Loads caused by piping (pneumatic conveyinthe dead load and those caused by superimpo

considered as applicable. The effect of these

must be considered.

6.6.9 Mechanical Loads (L9)

Mechanical loads are those caused by vibrato

aids, dischargers, etc.

6.6.10 Lift Condition6.6.10.1 Unless otherwise specified by the P

factor of 1.5 shall be applied to the

devices. The basis for the lift weigh

the design phase of the vessel so th

comprises all components to be inc

ladders/platforms, insulation, addit

etc.).

6.6.10.2 Bending stresses from loads impos

horizontal to vertical position in the

checked in vessels having h/D ratio

more than 25,000 pounds. Calculat

tensile stress shall not exceed 80%

minimum yield strength at 100F. C

shall not exceed 1.2 times the B fac

Vessel lifts are recommended when

of design wind velocity and the reswind velocity) is included in the co

6.6.10.3 For the imposed loads, local stresse

shell/head/skirt/base rings from the

trunnions, etc.) shall be determined

procedures such as WRC Bulletin 1

stress analysis procedures (e.g., fin

rigging condition, the allowable str

membrane stress and 3S for primar

bending stress. S shall be the Code

temperature.

6.6.11.4 Shear stresses for fillet welds on th

vessel shell/head shall not exceed 0



36/73


6.6.11 Load Combinations

The equipment and its supports shall be designedthe following load combinations:

1. L1+L5 Erected

load

2. L1+L2+L3+L4+L5+L8+L9 Design c

load (inc

pressure

of maxim

and com

3. L1+L2+L3+L4+L6+L8+L9 Design c

load (inc

pressure

of maxim

and com

4. L1+ L3+(0.25) L5+L7 Initial (n

conditioncondition

operatin

design w

load)

The gene

tensile st

condition

allowancload com

the follo

90%

yield

carb

The

stren

stain

5. Lift Condition See Sect

6.7 Vessel Support Systems



37/73


6.7.3 For combinations of earthquake or wind load

in Codeparagraph UG-22, the allowable stre

permitted by Codeparagraph UG-23(c). See combinations to be considered. See also Code

shape support members in compression wher

controlling design consideration, no increase

stress is permitted.

6.7.4 Stresses resulting from direct bending in supp

shall not exceed 1.5 times the Code-allowabl

stresses in support rings and lug gussets and o

shall not exceed 1.25 times the Code-allowab

6.7.5 Support skirts attached to the bottom head sh

outer portion of the head such that the outer d

the OD of the skirt coincide. The attachment

sized to accommodate the maximum imposed

PIP VEFV1128.

6.7.6 Support skirts created by extending the shell

weld joint shall be in accordance withPIP VE

6.7.7 Skirt diameter and height permitting, one or m

openings shall be provided to allow free acce

maintenance work inside the skirt. Where the

auxiliary running equipment, the minimum op

dimensions in accordance with site requireme

configurations shall be only by agreement bet

Supplier.

6.7.8 Skirt supports shall be provided with a minim

vent openings.

6.7.9 Leg supports shall be limited to vessels that m

Service is non-cyclic and non-pulsating

Vessel height-to-diameter ratio (h/D) ddistance from base of support to top tan

Note 1.)Note 1:Caution is advised for leg-support

h/D 5 but could have excessive axial andor an overstress condition in the vessel wa

6.7.10 For bins, hoppers, silos, and blenders that are



38/73

g p

6.7.10.4 Attached piping shall be designed for s

affect performance of the load cell syst

6.8 Top Head

6.8.1 Shallow conical heads and dished-only heads, inc

that are identified within the scope ofAPI 650(in

pressure rating of 2.5 psig) shall be designed in a

andAPI 650allowable stress values.

6.8.2 Head designs other than those identified within th

that exceed 2.5 psig pressure rating shall be in acits allowable stress values.

6.8.3 Roofs without operator platforms shall be design

of 25 pounds per square foot.

6.8.4 The product being handled can exert upward forc

vessel if overfilled and (1) the material is fluidize

angle with the horizontal plane that is greater than

repose for the product. Depending on the situatio

avoided by the following actions:

Eliminating overfill excursions through tighother such measures

Designing the top head to withstand the for(see Australian Code for force calculations

Designing the head to incorporate an angle

minimum angle of repose for the given mat6.8.5 The Designer shall consider additional concentra

from top-mounted equipment, such as bin vents, c

6.8.6 Use of standard flanged and dished heads is acce

conditions are met:

The inside crown radius is not greater than straight flange.

The inside knuckle radius is not less than thspecified head thickness after forming.

The minimum head thickness after formingwith Coderules.



39/73

6.8.7 The use of torispherical heads is acceptable.

pressure-induced buckling of large diameter,

radius-to-required head thickness greater thanheads, a design check of the Code-required th

One acceptable method (among several that h

Galletly. This check may reveal the need for

the Code-required minimum thickness.

6.9 Shell

6.9.1 Straight side heights-to-diameter ratios of 2:1

blenders are to be used for preliminary designoption to vary slightly the diameter and straig

utilize plate dimensions and available head di

economical fabrication.

6.9.2 Shell design shall include the wall pressure in

flow of solids on the basis of the flow test dat

design shall also consider forces that may res

created by flow through blend tubes, side disc

used to determine bulk loads for the purpose

upon by the Supplier and Purchaser.

6.9.3 The equipment shall sustain the axial load on

developed from vertical friction caused by th

internal dead load is additive to other dead lo

containing walls and roof above the support p

such as wind and seismic load.

6.9.4 The total axial load shall be used to computeresistance of the shell at the point of support

as the bottom cone-shell intersection and all o

6.9.5 When designing for mass flow, the internal w

as follows:

6.9.5.1 All longitudinal weld surfaces shall b

smooth finish, and all circumferenti

provided with a ground smooth finheight the lesser of 1/8 inch or 25% o

6.9.5.2 Weld surface finishes (i.e., ground sm

with Appendix C ofNACE RP0178.

6.9.6 Where walls of the vessel are of different thic



40/73

modeling or another type of in-depth analysis sha

components as agreed upon by the Purchaser.

6.10.3 When designing for mass flow, all internal weld s

with either a ground flush or ground flush and

surface finishes (e.g., ground flush) shall be in

Appendix C ofNACE RP0178. The Designer sha

surface finish(es) selected on the vessel data shee

6.10.4 The Designer shall consider the angle of friction

material with the contained product, which will a

wall slopes, in the design. The angle of friction shrepresentative samples of hopper wall material an

6.11 Shell-to-Bottom Joint (Skirt Ring)

The shell-to-bottom joint shall be designed in accordance

allowable stress values. Codeparagraph 1-5 shall be used

reinforcement for internal pressure, and Codeparagraph

design of reinforcement for external pressure. This joint e

pressure spike caused by the behavior of the contained soshall be used in the design of this joint and its reinforcem

6.12 Vessel Connections

6.12.1 Flanges for nozzle and body sizes NPS 24 and sm

withASME B16.5. If required, blind covers shall

ASME B16.5or designed per the Code, paragraph

in accordance withASME B16.21. Flanges design

Code, Appendix 2, are also acceptable if the boltiare in accordance withASME B16.5.

6.12.2 Flanges for nozzle and body sizes larger than NP

accordance with the Code, Appendix 2, with bolt

in accordance withASME B16.47, Series B flang

pressure for these flanges shall be 50 psig.

6.12.3 Flanged joints for stainless steel and nonferrous c

lap joint type with carbon or low-alloy steel flang

NPS 24 and smaller shall be furnished in strict ac

ASME B16.5. The nominal outside diameter of la

raised face diameter inASME B16.5standard flan

6.12.4 Flanges for manways shall be designed in accord

Appendix 2 Manway covers shall be blinds desig



41/73

6.12.6 Service requirements result in significant me

pressure. The pressure-temperature ratings of

ASME B16.47are based primarily on pressurflanges may not be suitably designed for exte

thrust loads, resulting in leak-tightness proble

method usually employed for considering suc

6.12.7 Flange rigidity, when specified on the data sh

with the Code, Appendix S.

6.12.8 Custom-designed flanges (CodeAppendix 2)

following minimum SA-193 Gr. B7 stud/bolt 3/4 inch for NPS 6 - NPS 16 flanges

7/8 inch for NPS 18 - NPS 36 flanges

1 inch for flanges larger than NPS 36

Note: 1-inch and larger bolts shall have 8 t

Note: Bolts shall have rolled threads.

Note: The arc length between bolt centers

exceed inches for bolts 1-inch diameter bolts shall be divisible by 4 and shall strad

approval shall be obtained to deviate from

Appendix E for the method usually emplo

mechanical loads other than pressure.

6.12.9 Minimum radial distance for wrench clearanc

shall be as follows: 1-1/8 inches for 3/4-inch-diameter bolt

1-1/4 inches for 7/8-inch-diameter bolt

1-3/8 inches for 1-inch-diameter bolts

1-1/2 inches for 1-1/8-inch-diameter bo

1-3/4 inches for 1-1/4-inch-diameter bo

6.12.10 Carbon or low-alloy steel lap joint-type flang

joints of stainless steel and nonferrous compo

diameter of laps shall be the same as the raise

ASME B16.5for nozzle and body sizes NPS 2

finished thickness of custom-designed lap joi



42/73

and should be sufficient to allow the la

back, if necessary, to maintain parallel

6.12.11 Stub ends produced by the vessel Supplier are no

ASME B16.9as long as the stub ends meet the req

flanged connections NPS 24 and less, the dimens

ASME B16.9shall be met except the length may b

additional weld.

6.12.12 Standard flanges and factory-made stub ends sha

accordance withASME B16.5orASME B16.47, a

flanges in service requiring special considerationfabricated lap-joint stub ends require the gasket-b

serrated concentric or serrated spiral (no radial to

allowed) surface finish of 125250 Ra (roughnes

finish shall be judged by visual comparison with

ASME B46.1) and not by instruments having stylu

amplification.

6.12.13 Applied metallic linings used on gasket-bearing s

after Purchaser approval. If proposed, the design submitted for Purchaser approval. Applied lining

finished thickness of 3/16 inch.

6.12.14 Flange stops are required below loose flanges on

and vessel cylinders.

6.12.15 Studding pads (pad flanges) NPS 24 and smaller

ASME B16.5bolting dimensions, and studding pa

shall have standardASME B16.47Series B boltin

6.12.16 The flange assembly data for gasketed joints and

and gasketed body joints NPS 10 and larger shall

drawing(s). SeeASME PCC-1

for flange assembl

6.12.17 Nozzles NPS 18 and larger and manways NPS 24

covers shall be equipped with either a davit or hin

the blind flange. Nozzles and manways with the n

horizontally shall be equipped with a hinge in acc

PIP VEFV1116 or a davit in accordance withPIPdavit socket bracket to the nozzle neck when lap j

Nozzles and manways on top of vessels oriented

axis shall be equipped with a davit in accordance

6.12.18 Minimum nozzle projection shall be 6 inches for



43/73

6.12.19 Static nozzle loads, other than agitators, shall

WRC Bulletin 107. Special nozzle loads such

(identified by the Purchaser) will require a hianalysis is subject to Purchaser approval.

6.12.20 The minimum size connection shall be 1-1/2

6.12.21 Nozzle and manway openings shall not be ma

6.12.22 The Designer shall determine the need for re

larger than 2 inches, in accordance with the C

6.13 Gaskets

6.13.1 The dimensional requirements ofASME B16

gaskets. Any deviation from these standard g

submitted for Purchaser approval. The data sh

spare gaskets to be furnished by the Supplier.

Exceptions to the standard dimensions ofASM

Purchaser approval.

6.13.2 Gasket type(s) and rating(s) shall be specifiedspecified gasket m and y design factors w

sheet.

6.13.3 Minimum gasket width for custom sheet gask

Nmin= (Ab)(Sb)/2(y)(G)

where

Ab = sum of cross sectional areas of basic mininch2

Sb= bolt allowable stress, Psi

y = ASME Codey factor, Psi

G = mean diameter of gasket, inch

Note: Under no circumstance shall the actu

used be less than the following:

5/8 inch for NPS 6NPS 20 flanges

3/4 inch for NPS 24NPS 36 flanges

1 inch for flanges larger than NPS 36



44/73

6.14 Internal Components

6.14.1 Internal piping, attachments (blend tubes, well pi

cones shall be adequately supported. Purchaser re

support bracket/attachment calculations is require

6.14.2 Design of internal components shall consider forc

flow patterns that may be caused by discharge thr

discharge nozzles, etc.

6.15 Corrosion Allowance

The Designer shall evaluate the requirement for a corrosiall parts of the bin or hopper contacting the contained pro

specified, the minimum nominal corrosion allowance for

the service product shall be as follows:

0 inches - stainless steels and all non-ferrous alloys

1/16 inch - carbon and low-alloy steels

6.16 Compartment VesselsCommon component(s) of vessels having more than one c

designed for the most severe combinations of pressure, va

other loads that may occur during operation and test cond

of simultaneous loading of internal pressure in adjacent c

acceptable.

6.17 Minimum Thickness

6.17.1 The minimum nominal material thickness exclusiallowance for pressure-retaining non-piping, non-

as follows:

Carbon steel - 1/4 inch

Aluminum - 1/4 inch

Stainless steel and other high alloys - 3/16

6.17.2 The minimum nominal material thickness exclusiallowance for pressure-retaining components (oth

components) when using piping components shal

Carbon steel - standard weight

Aluminum Schedule 10



45/73

Carbon steel - Schedule 80

Aluminum - Schedule 80 Stainless steel and other high alloys - S

6.17.4 The minimum nominal thickness for all flang

6.17.5 For tubular products, minimum thickness sha

corrosion/erosion allowance.

6.18 Anchor Bolting

6.18.1 Design stresses - Anchor bolts shall not be smdesign tensile stresses for carbon steel anchor

tensile stress area of the threaded portion, sha

6.18.2 Carbon steel anchor bolts shall have a 1/8-inc

minimum.

6.18.3 Spacing and location - Anchor bolts for verti

multiples of four bolts. Purchaser shall furnis

6.19 Lifting Lugs

6.19.1 Lifting lugs shall be installed as a permanent

shall be capable of lifting and supporting the

appurtenances. See data sheet(s) for lifting lu

vertical vessels shall be located near the top o

lifting and erecting the vessel from a horizont

position. Tailing lugs are required for positio

approved by the Purchaser. Lifting lug designto the Purchaser for review.

6.19.1.1 A minimum impact factor of 1.5 s

weight.

6.19.1.2 Two ear-type lugs spaced 180 deg

straight portion of the top of the sh

6.19.1.3 Welding across the bottom of the

drainage. A bead of room temperasealant shall be used after painting

lug and the surface to which the lu

6.19.1.4 Lifting lug and tailing lug design c

the Purchaser for review before lu



46/73

6.20 Structural

6.20.1 Roof platforms and platform framing and support

according toPIP STF05535.

6.20.2 Horizontal external stiffener members shall be or

build-up of material on the stiffeners. Channels a

downward-turned flanges/legs, and beams, stiffen

drain holes.

6.20.3 All inside edges of nozzles, manways, and other c

rounded to a minimum 1/4-inch radius.

7. Materials

All materials shall be in accordance with the Code.

7.1 Allowable Stress Values

Except as allowed in Section 6.7.1 of this Practice for top

accordance withAPI-650, allowable stresses used in the dshall be in accordance with the Code. For combinations o

loadings with other loadings listed in Codeparagraph UG

may be increased as permitted by Codeparagraph UG-23

load combinations to be considered. See also CodeAppen

7.2 Carbon Steel

Where carbon steel is the selected material, the following

7.2.1 Flanges for aluminum lap joint stub ends shall be

7.2.2 Pressure bolting shall be SA-193, Grade B7 bolts

2H heavy hex nuts.

7.3 Stainless Steel

When specified in the vessel specifications, all formed he

austenitic (type 304 and type 316 only, including low-car

or duplex stainless steel shall be solution annealed after fASME SA-480.

7.4 Clad Material

7.4.1 All integrally clad plate, including explosion clad

ASME SA 263 ASME SA 264 and ASME SA 265



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7.5 Prohibited Materials

The following materials are prohibited:

Mercury-containing products

Cadmium-plated products

SA-515 and SA-414 (B-G) carbon steels unlessrecognized industry standard are met

8. Fabrication

8.1 General

8.1.1 Bulk solids bins, hoppers, silos, and blenders

present a smooth internal surface to the conta

8.1.2 Internal members shall be clearly noted with

drawings.

8.1.3 Any temporary internal fixtures (e.g., bracing

etc.) required for fabrication, erection, and fit

and the affected area shall be ground smooth.

cone of a mass flow silo, the area shall be gro

NACE RP0178for definitions).

8.1.4 Nozzles intended for use with a safety relief d

vessel discharges shall be trimmed flush insid

8.1.5 When a carbon steel attachment is welded to

component, an alloy transition pad designed compatible with the pressure-retaining compo

the attachment and the component. A 1/4-inc

or a 1-inch gap in the weld is required.

8.2 Welding

8.2.1 All welds, including those attaching non-pres

shall be made by welders (or welding operato

procedures qualified under the provisions of

8.2.2 Vessel shall be all-welded construction, exce

attached by bolting. Unless otherwise specifi

penetration, double- or single-welded butt joi

fissures. Lap joint seam welds are acceptable



48/73

slip-on flange to nozzle neck connections

nozzle to top head connections

lap joint seam welds in segmented domed t

conical head seam welds

8.2.3 Longitudinal weld seams in adjoining shell sectio

minimum of 6 inches apart.

8.2.4 Non-butt joints connecting nozzles (includes man

studding outlets) to vessel wall shall be full penet

through the entire thickness of the vessel wall andreinforcing plates (when used). Nozzles designate

inside surface of the vessel wall shall have an add

inside nozzle neck and vessel wall corner.

8.2.5 Welding on pressure-resisting components and gr

grinding) on pressure-resisting welds is not perm

unless approved in writing by Purchaser.

8.2.6 When connecting tubing to form blend tubes for diameter of the lower section of tubing in a joint

than that of the upper section of tubing in the join

material from collecting on the ledges in the joint

8.2.7 Intermediate or skip welding is not acceptable ex

8.2.8 Deposited weld metal shall be essentially of the s

composition as the material joined.

8.2.9 Butt-welded joints in vessel support skirts shall mrequirements: Welded joints shall be of CodeCat

used, butt-type Category C shall be Type No. (1)

8.2.10 The minimum distance from the toe of filletweld

wear plates, to the centerline of either a longitudi

seam shall be Rt where R = shell inside radiusinches, exclusive of corrosion allowance.

8.3 Flanges

8.3.1 Bolt holes in all fixed flanges and studding outlet

centerlines.

8.3.2 Bolt holes in flanges of nozzles in heads shall str



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8.4 Prohibited Construction

The following are prohibited:

Lap-joint seam welds except as noted in Sectio

Single butt welds with backing material (strips,

Nozzle openings in weld seams, unless agreed t

Weld joints on gasket-bearing surfaces not mac

Single inner or outer fillet welds for any welded

components Pinch rings (outer flange face rings) in flanged

by Purchaser

Permanent weld-joint backing strips

Nozzles attached per the Code, Figures UW-16Exceptions to these requirements shall be defin

Supplier and shall require Purchaser approval.

Weld joints covered by attachments such as reito by the User.

8.5 Tolerances

8.5.1 All equipment shall meet the manufacturing t

purchase order or on the drawings. Tolerance

shown onPIP VEFV1102shall apply to the c

test.

8.5.2 The cutting of stainless steel shall be by mech

sawing, or machining. If cutting is done by an

arc, air arc, etc.), an allowance shall be made

1/8 inch of metal (i.e., 1/4 inch in the diamete

or grinding to the finished dimensions. Speci

required before thermal process cutting can b

8.6 LiningsThis section covers the additional requirements neces

lined with an elastomeric, thermoplastic, reinforced th

cured polymer system. These requirements are the res

Supplier to complete before the lining contractor inst

i f h li i h ll b i i



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8.6.1 General

8.6.1.1 Equipment shall be fabricated in accorda

shall meet the special requirements for su

section.

8.6.1.2 All vessels with non-metallic linings shal

painted on two sides of the shell and insu

(and/or channel) in 3-inch-high letters vis

position from grade:

LINED VESSEL - DO NOT BURN OR W

8.6.2 Weld Acceptance Standards

8.6.2.1 Sample preparation - The Supplier shall s

samples, each 6 inches long, for vessel bo

welds on the shell, horizontal welds on th

The samples may be ground as required.

is required only if overhead welding is us

head.

8.6.2.2 Sample evaluation - The samples shall be

approval at the same time as the drawing

approval. After evaluation by the Purchas

will be returned to the Supplier for Suppl

will be given to the Purchasers inspector

standard. If the samples are not approved

shall be given to the Supplier and new sa

submitted for approval.

8.6.3 Design and Fabrication Requirements

8.6.3.1 Joints - All joints in shell and heads shall

welded bottoms or roofs are not allowed.

shall be ground smooth, and the inside co

bottom joint of flat bottom vessels shall b

minimum radius of 1/4 inch. The top hea

vessel top heads shall be constructed so th

formed. Details a, d, e, g, h, and i ofAPI used. The inside surface of the weld joint

concave to a minimum radius of 1/4 inch

8.6.3.2 Nozzles - All nozzles shall be flanged. Th

couplings and fittings are not permitted. A



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manway) in the top head in addition t

manways are located on the shell, the

8.6.3.3 Internal components - All sharp corn

structural members shall be rounded

minimum, and all fillet welds shall be

minimum radius. If internal compone

be made of a corrosion resistant mate

avoided. If bolted joints are necessary

corrosion resistant bolting, and the m

before assembly. The sealing surface

have gaskets to protect the lining. Dielectrically insulated from the vessel

by the use of a sleeve. Structural rein

installed on the equipment's exterior.

members shall be installed externally

8.6.3.4 Welding - All welding shall be of the

and spot welding is not permitted. Al

produce a smooth weld surface with

minimizes the grinding of the finishe

8.6.3.5 Surface finish - Vessel surfaces to be

handling marks, deep scratches, meta

other surface flaws. All flaws repaire

grinding. All rough welds shall be gr

undercuts, pinholes (these shall be fil

such irregularities. All weld splatter m

be used to remove sharp edges if foll

abrasive disc.

9. Inspection and Testing

9.1 Inspection

9.1.1 Vessel inspection by the Purchaser or Purcha

required at the Suppliers shop and the User

points shall be established before fabricationquality assurance procedures shall be made av

Purchasers representative upon request.

9.1.2 The Purchaser shall be allowed to make dye p

location selected by the Purchaser to determi



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9.1.4 All assemblies that become damaged (dented, kin

fabrication, handling, or shipment shall be replac

satisfaction of the Purchaser, at the Suppliers exp

9.1.5 All shell and head butt welds shall be inspected w

radiography in accordance with Codeparagraph U

9.1.6 Finished surfaces of welded pressure joints that w

assembly shall be examined by the liquid penetra

with Appendix 8 of the Codeand repaired as requ

9.1.7 Formed heads shall be seamless, or, if welded, th

head is to be made shall be radiographed per Codknuckle region of the head, including the straight

the spherical portion, before forming.

9.2 Testing, General

9.2.1 All vessels shall be neither painted nor shot-peen

9.2.2 For atmospheric vessels with a total volume 500 ft3or with

constructed for pressures 15 PSIG, a combinatitest shall be performed on the vessel in the operat

Supplier at the Suppliers shop or the Users oper

test shall be performed at a pressure equal to and of the vessel. The weight of the water used during

the expected operating weight of the solids in the

shall not exceed the top head to shell joint. This p

represent as closely as practical the operating stat



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9.2.6 Test pressures shall be maintained for a mini

application of the test pressure, an inspection

connections. The inspection shall be made at the test pressure.

9.2.7 For vessels that consist of two or more comp

shall be given a separate and individual test w

adjacent compartments.

9.2.8 When testing vessels with water, the test wat

debris. Only potable water with a chlorine ion

50 ppm shall be used when testing stainless s

9.2.9 Vessels shall be field tested for leaks after in

responsible for repairs to vessels if leaks are

pressure.

9.2.10 The vessel metal temperature, for the entire d

colder than 30F above the minimum design

Section 6.4) and not hotter than 120F.

9.2.11 The Supplier(s) shall furnish all blind flangestypes of blanking covers as may be required)

connections not specified to be furnished with

flanges and bolting (or other type covers) ma

remain the property of the Supplier.

9.2.12 Test gaskets - Any flanged joint for which th

service gasket and for which disassembly wil

tested with the specified service gasket identi

joint is to be disassembled after testing and eASME B16.5, the Supplier may select the test

limitations identified in the purchase requisit

approve the test gasket to be used if the joint

employs non-standard flanges (other thanASM

gasket is not specified.

9.2.13 Repairs to eliminate imperfections revealed d

test failure, shall be tested at the Suppliers e

original test(s).

9.2.14 Body flanges, manways, and nozzles specifie

flanges shall be left undisturbed and assembl

10 Shipping



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10.1.2 Welding attachments to vessels for shipping purp

10.1.3 At least one of the vessel connections shall be us

shipping. The connection used for venting shall bfabric secured with tape at the edges of the fabric

10.1.4 The Supplier shall take all necessary precautions

bracing the vessel and any internals to prevent da

10.1.5 The exterior of the vessel shall be protected such

damaged.

10.1.6 The Supplier shall identify all separately package

the purchase requisition.

10.1.7 See data sheet for any additional shipping require

10.2 Cleaning and Painting

10.2.1 The Supplier shall completely drain, thoroughly d

grease, oil, weld scale (carbon steel), weld splatte

other foreign matter from inside and outside the v

before shipment or after fabrication and testing ifUsers plant site. Any additional cleaning require

the purchase order.

10.2.2 Vessels shall be completely dry, and all openings

securely sealed before shipment.

10.2.3 All temporary identification markings shall be rem

vessel.

10.2.4 Preparation and painting of the exterior of all fabrelated attachments shall be in accordance withP

shall be performed after pressure tests except on

painted that will be inaccessible after assembly (e

between lap-joint flanges and nozzle necks, shell

bolt holes, and welded joints). These surfaces sha

assembly and testing.

10.3 Preparation for Shipment10.3.1 Assembled Machined Surfaces

Body joints, manways, blind-flanged nozzles, plu

connections specified to be furnished with servic

assembled if practical If testing gaskets are shipp



55/73

Oil-Tectyl 858C, Sanchem No-Ox-

Houghton-Rust Veto Heavy; other

acceptable.10.3.2.2 All flange faces (except one for ven

with 1/2-inch-thick plywood no sm

diameter and secured with a minim

steel bolts, but no fewer than four,

flange circumference. Pre-fabricate

acceptable.

10.3.2.3 Nozzle necks without flanges beve

shall be provided with bevel protec

10.3.2.4 Threaded connections shall be capp

plastic material.

11. Instrumentation

11.1 General

The Designer shall evaluate the need for instrumentat

temperature, level, and weight indicators.

11.2 Side-Entry Instrumentation

Level indicators shall be installed in accordance with

and detail drawings provided with the instrumentation

tent) shall be provided by the vessel Supplier in acco

instrumentation manufacturers instructions as requirconfigurations.

12. Nameplates and Stampings

12.1 Nameplates

The Supplier shall be responsible for assuring installa

provides the as-built fabrication and construction con

Required nameplate markings shall not be stam

The nameplate shall be made either of a 300 sealloy or equivalent and shall be attached secure

h S li h ll i ll l b



56/73

Users equipment item number

Initial test pressures

Purchase order number

Vessel weight

MAWP (see Section 6.2)

MDMT (see Section 6.3)

Design maximum bulk density

Design minimum bulk density

Radiography inspection level (i.e., RT 1, 2, 3, 4)



57/73

APPENDIX A

Quality Overview Plan forVessels for Solids



58/73

APPENDIX A

Quality Overview Plan for

Vessels for Solids

Equip. No. ______________________ P. O. No. S. O. No.Equip. DescriptionProject Engineer Inspection Contact

Activities checked apply to the above

Date post:	01-Jun-2018
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