Asme Section Viii Pwht Requirements

Sections of ASME Boiler and Pressure vessel Codes (BPVC)

The following list includes some of the most widely used Boiler and Pressure Vessel codes (BPVC) prepared and published by ASME.

Section I……………………Rules for construction of Power Boilers

Section II…………………..Materials

Note: This information has all been taken from a white paper intended to support revision to the PWHT rules in several ASME Codes. It provided a comparison to the current rules and demonstrates some of. Exemption from PWHT for seal weld between P-No.4 Tubes and P-No.4 Tubesheets from PWHT requirements of Table UCS-56-3 Section VIII, Division 1 Question: Under what conditions may seal welds connecting P-No. 4 tubes to P- No. 4 tubesheets be exempt from postweld heat treatment. PWHT is ASME Code Section 8 requirement if thickness exceeds those given in tables UCS-56 (given in notes under the tables). These tables also give min. PWHT temperature and min. This PetroKnowledge online training course covers the requirements of ASME BPVC, Section VIII, Division 1 (2019) including background, organization, design, materials, fabrication, inspection, testing and documentation of pressure vessels. BPVC-VIII-1 - Section VIII, Rules for Construction of Pressure Vessels, Division 1 BPVC-IX - Section IX, Welding and Brazing Qualifications Referenced ASME Standards B1.20.1 -Pipe Threads, General Purpose, Inch Twelve Standards from the B16 Series on pipe flanges and fittings B31.1 - Power Piping B36.10M - Welded and Seamless Wrought Steel.

Part A. Ferrous Material Specifications
Part B. Nonferrous Material Specifications
Part C. Specifications for Welding, Rods, Electrodes and Filler Metals
Part D. Properties

Section III………………….Rules for Construction of Nuclear Facility Components

Subsection NCA. General Requirements for Divisions 1 and 2

Division 1

Subsection NB. Class 1 Components
Subsection NC. Class 2 Components
Subsection ND. Class 3 Components
Subsection NE. Class MC Components
Subsection NF. Supports
Subsection NG. Core Support Structures
Subsection NH. Class 1 Components in Elevated Temperature Service

Division 2. Code for Concrete Containment

Division 3. Containment Systems for Storage and Transport Packaging of Spent Nuclear Fuel and High Level Radioactive Materials and Waste

Section IV …………………Rules for Construction of Heating Boilers

Section V…………………..Nondestructive Examination

Section VI………………….Recommended Rules for the Care and Operation of Heating Boilers

Section VII…………………Recommended Guidelines for the Care of Power Boilers

Section VIII………………..Rules for Construction of Pressure Vessels

Division 1. Pressure Vessels
Division 2. Alternative Rules for Pressure Vessels
Division 3. Alternative Rules for Construction of High-Pressure Vessels

Section IX…………………Welding and Brazing Qualifications

Pwht requirements as per asme section viii div 1

Section X………………….Fiber-Reinforced Plastic Pressure Vessels

Section XI…………………Rules for Inservice Inspection of Nuclear Power Plant Components

Section XII………………..Rules for Construction and Continued Service of Transport Tanks

Brief introduction of some of the widely used BPVC sections:

SECTION I: Section I gives requirements for construction of

Power Boilers, Electric Boilers, Miniature boilers
Heat recovery steam generators (HRSG)
Power boilers used in Locomotive, Portable and Traction type
High temperature water tube boilers
Certain fired pressure vessels to be used in stationary services

SECTION II: Section II is exclusively dedicated to materials and its specifications. These specifications contain requirements for chemical and mechanical properties and other necessary details. It includes four parts viz. Part A, Part B, part C and Part D.

Part A – Ferrous Material Specifications

It provides specifications for ferrous materials which are suitable for use in the construction of pressure vessels. The specifications provided in this part gives the mechanical properties, heat treatment, heat and product chemical composition and analysis, test specimens, and methodologies of testing. They are designated by ‘SA’ numbers and are identical or similar to those published in ASTM specifications.

Part B – Nonferrous Material Specifications

It provides specifications for nonferrous materials. The specifications provided in this Part specify the mechanical properties, heat treatment, heat and product chemical composition and analysis, test specimens, and methodologies of testing. They are designated by SB’ numbers and are identical or similar to those published in ASTM specifications.

Part C – Specifications for Welding Rods, Electrodes, and Filler Metals

It provides mechanical properties, heat treatment, heat and product chemical composition and analysis, test specimens, and methodologies of testing for welding rods, filler metals and electrodes used in the construction of pressure vessels.

They are designated with ‘SFA’ numbers which is derived from the American Welding Society (AWS) specifications.

Part D – Properties (Customary/Metric)

It provides tables for the design stress values, tensile and yield stress values and material properties.

SECTION III: It provides guidelines for construction of nuclear facility components and supports as well. Section III includes different divisions and subsections.

SECTION IV: Provides guidelines for design, fabrication, installation and inspection Heating boilers, such boilers are primarily used for:

Steam Heating
Hot water heating
Hot water supply boilers
Potable water heaters

These boilers are meant for low pressure service and are directly fired by solid or liquid fuels such as coal, oil, gas, electricity etc.

SECTION V: This section is dedicated Non-Destructive tests (NDT). It provides for requirements and methods for non-destructive tests. It also contains the detailed duties of authorized inspectors, manufacturer’s examination responsibility, and requirements for qualification of personnel, inspection and examination. These examination methods are a key to detect the discontinuities present in the material, weld and fabricated components. It also includes a glossary of all related terms.

SECTION VI: Provides guidelines for operation and maintenance of Heating boilers which are manufactured as per Section IV.

Section VI also covers guidelines for associated controls and automatic fuel-burning.

SECTION VII: Provides guidelines for operation, maintenance and inspection of power boilers. It also includes the necessary guidelines for operation of auxiliary equipments and appliances that are directly responsible for safe and reliable operation of power boilers.

Boilers which come under the purview of Section VII are Stationary, Portable and Traction type boilers, but not Locomotive and High temperature water boilers, Heating boilers (Section VI) and Nuclear power plant boilers (Section XI).

SECTION VIII: It provides detailed guidelines for the design, fabrication, testing, inspection, and certification of pressure vessels (both fired and unfired). Section VIII includes three divisions viz. Division I, Division II and Division III

Division 1: Division provides guidelines for design, fabrication, inspection, testing and certification of pressure vessels operating at either internal or external pressures exceeding 15 psi (100 Kpa).

Division 2: It provides requirements for the materials, design, and Non destructive examination for pressure vessels. Division 2 standards are more rigorous than division 1. However it allows for higher stress intensity values. These rules may also be applied to human occupancy pressure vessels such as those used in the diving industry.

Division 3: It provides guidelines for pressure vessels operating at or more than 10,000 psi (in general) either internally or externally. Maximum pressure limit is no where mentioned in the code even in divisions 1 and 2 too.

SECTION IX: This Section covers necessary guidelines and requirements pertaining to welding and brazing procedures (as per the requirements of other BPVC standards). It also contains guidelines for qualification and requalification of welders, welding operators and brazing operators. It also contains all the essential, non essential and supplementary essential variables required for welding and brazing.

Section IX is further divided into four parts, Namely

Part QG: Contains General Requirements for all material – joining processes (viz. Welding, Brazing and Plastic Fusing)
Part QW: Contains requirements for Welding
Part QB: Contains requirements for Brazing
Part QF: Contains requirements for Plastic Fusing

(NOTE: Detailed summary for Section IX including preparation of welding procedure specification (WPS), steps followed for Procedure Qualification Record (PQR), Welder performance qualification test, range and limits etc. has been explained separately).

To learn the steps involved in writing a welding procedure specification, please click here.

To understand welder performance qualification, Please click here.

To understand the thickness limit for performance and prcocedure qualification, please click here.

SECTION XII: It provides guidelines for construction and continued service of pressure vessels used for transportation of dangerous goods at pressures from full vacuum to 3000 psi and volume greater than 120 gallons.

List of some of the most widely used ASME Standards:

Pwht Requirements As Per Asme Section Viii Div 1

CSD-1……………………….Controls and Safety Devices for Automatically-fired Boilers

B1.1…………………………..Unified Inch Screw Threads (UN and UNR Thread Form)

B1.20.1 ……………………..Pipe Threads, General Purpose (Inch)

B16.1…………………………Cast-iron Pipe Flanges and Flanged Fittings

B16.3…………………………Malleable Iron Threaded Fittings, Classes 150 and 300

B16.4…………………………Gray Iron Threaded Fittings, Class 125 and 250

B16.5…………………………Pipe Flanges and Flanged Fittings

B16.9…………………………Factory-made Wrought Steel Buttwelding Fittings

B16.11 ………………………Forged Fittings, Socket-Welding and Threaded

B16.15 ………………………Cast-bronze Threaded Fittings, Classes 125 and 250

B16.20 ………………………Ring-joint Gaskets and Grooves for Steel Pipe Flanges

B16.24 ………………………Cast Copper Alloy Pipe Flanges and Flanged Fittings

B16.25 ………………………Buttwelding Ends

B16.28 ………………………Wrought Steel Buttwelding Short Radius Elbows and Returns

B16.34 ………………………Valves — Flanged, Threaded and Welding End

B16.42 ………………………Ductile Iron Pipe Flanges and Flanged Fittings, Classes 150 and 300

B16.47 ………………………Large Diameter Steel Flanges, NPS 26 Through NPS 60

B18.2.2 …………………….. Square and Hex Nuts (Inch Series)

B31.1 ………………………… Power Piping

B31.2 ………………………… Fuel Gas Piping

B31.3 ………………………… Process Piping

B31.4 ………………………… Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids

B31.5 ………………………… Refrigeration Piping and Heat Transfer Components

B31.8 ………………………… Gas Transmission and Distribution Piping

B31.9 ………………………… Building Services Piping

B31.11 ……………………… Slurry Transportation Piping

B36.10M …………………… Welded and Seamless Wrought Steel Pipe

QAI-1 ………………………….. Qualifications for Authorized Inspection

PVHO-1 ………………………. Safety Standard for Pressure Vessels for Human Occupancy

ASME PERFORMANCE TEST CODE PTC 25……………………..Pressure Relief Devices

List of important ASNT Standards

ACCP …………………………Central Certification Program

CP-189 ……………………..Standard for Qualification and Certification of Nondestructive Testing Personnel

SNT-TC-1A……………… Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing

List of some of the most widely used ASTM standards

A 126……………………….. Standard Specification for Gray Iron Castings for Valves, Flanges and Pipe Fittings

B 139 ………………………..Standard Specification for Phosphor-Bronze Rod, Bar and Shapes

D 56…………………………. Standard Test Methods for Flash Point by Tag Closed Tester

D 93…………………………. Standard Test Methods for Flash Point by Pensky-Martens Closed Tester

E 8 …………………………….Standard Test Methods of Tension Testing of Metallic Materials

E 83…………………………..Methods of Verification and Classification of Extensometers

E 125…………………………Reference Photographs for Magnetic Particle Indication on Ferrous Castings

E 140…………………………Hardness Conversion Tables for Metals

E 186…………………………Standard Reference Radiographs for Heavy-walled (2 to 4-1/2 inch) Steel Castings

E 208…………………………Method of Conducting Drop Weight Test to Determine Nil Ductility Transition Temperature of Ferritic Steel