Canadian Common Practice in Piping Design and Pipe Stress Analysis

1. Introduction

1.1. Definition of Piping

1.2. Piping Nomenclature & Components

1.3. Regulatory Acts, Codes & Standards

1.4. Line Designation Tables

1.5. Important Questions

2. Codes & Standards

2.1. ASME

2.2. NEPA / NFC / NFPA

2.3. CSA

2.4. MSS

2.5. API

2.6. ASTM

3. Supplemental Documents

3.1. Owner’s Specifications & Documents

3.2. Contractor’s Standards & Documents

4. Piping Design

4.1. Failure Mechanisms

4.2. Code Considerations for Design

4.3. Material Selection

4.4. Fabricated Tees & Area Reinforcement

4.5. Piping Flexibility Analysis

1.0 Introduction

1.1 Definition of Piping

Pipe is a pressure tight cylinder used to convey a fluid or to transmit a fluid pressure, ordinarily designated pipe in applicable material specifications. Materials designated tube or tubing in the specifications are treated as pipe when intended for pressure service.

Piping is an assembly of piping components used to convey, distribute, mix, separate, discharge, meter, control or snub fluid flows. Piping also includes pipe-supporting elements but does not include support structures, such as building frames, bents, foundations, or any equipment excluded from Code definitions.

Piping components are mechanical elements suitable for joining or assembly into pressure-tight fluid containing piping systems. Components include pipe, tubing, fittings, flanges, gaskets, bolting, valves and devices such as expansion joints, flexible joints, pressure hoses, traps, strainers, in-line portions of instruments and separators.

Piping is typically round.

1.2 Piping Nomenclature, Components

Piping Nomenclature, Components by meena rezkallah, p.eng. the best piping stress engineer

Graphic of piping system illustrating

  • header

  • branch connection

  • valve

  • flange

  • expansion joint

  • expansion loop

  • pipe support

  • reducer

  • elbow

1.3 Regulatory Acts, Codes & Standards


Codes are rules for the design of prescribed systems which are given the force of law through provincial, state and federal legislation. In Canada, provincial governments have the responsibility for public safety which includes these facilities, among others:

  • Pressure piping

  • Pressure vessels

  • Boilers

  • Pipelines

  • Plumbing systems

  • Gas piping

Alberta Safety Codes Acts and Codes of Practice

The following are applicable to the first four facilities listed above.

Boilers and Pressure Vessels Regulation

  • Prescribes requirements for registration of pressure vessels, boilers, pressure piping and fittings

Design, Construction and Installation of Boilers and Pressure Vessels Regulations

  • Cites the codes and “bodies of rules” that form part of the regulations

  • CSA B51 Boiler, Pressure Vessel and Pressure Piping Code

  • CSA B52 Mechanical Refrigeration Code

  • CAN/CSA Z184 Gas Pipeline Systems

  • ASME Boiler & Pressure Vessel Code

  • ASME B31 Pressure Piping Codes

  • B31.1 Power Piping

  • B31.3 Process Piping

  • B31.4 Liquid Transportation Systems for Hydrocarbons, Liquid Petroleum

  • Gas, Anhydrous Ammonia and Alcohols

  • B31.5 Refrigeration Piping

  • ANSI K61.1 Safety Requirements for the Storage and Handling of Anhydrous

  • Ammonia

  • NFPA 58 Standard for the Storage and Handling of Liquefied Petroleum

  • Gases

  • DOT Regulations of the Department of Transportation Governing the

  • Transportation of Hazardous Materials in Tank Motor Vehicles

  • MSS Standard Practice SP 25 Standard Marking System for Valves, Fittings,

  • Flanges and Unions

  • TEMA Standards of Tubular Exchanger Manufacturers Association

Pipeline Act

Cites the “minimum requirements for the design, construction, testing, operation,

maintenance and repair of pipelines”:

  • CAN/CSA Z183 Oil Pipeline Systems

  • CAN/CSA Z184 Gas Pipeline Systems

  • CSA Z169 Aluminum Pipe and Pressure Piping Systems

  • Canadian Petroleum Association Recommended Practice for Liquid Petroleum

Pipeline Leak Prevention and Detection in the Province of Alberta

Currently, CSA Z662 Oil and Gas Pipeline Systems

(This standard supersedes Z183 & Z184)

In the US:

As in Canada, some facilities are governed by federal regulations. Interstate pipeline

facilities are defined by the:

  • Code of Federal Regulations, Title 49

  • Part 192 Transportation of Natural and Other Gas by Pipeline – Minimum Federal Safety Standards

  • Part 193 Liquefied Natural Gas Facilities

  • Part 195 Transportation of Hazardous Liquids by Pipeline

Other pipeline pressure piping codes include:

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

  • ASME B31.8 Gas Transmission and Distribution Systems

1.4 Line Designation Tables

The Province of Alberta Safety Codes Act "Design, Construction and Installation of Boilers & Pressure Vessels Regulations" par 7(2) requires that construction of a pressure piping system must include submission of drawings, specifications and other information and include:

  1. flow or line diagrams showing the general arrangement of all boilers, pressure vessels, pressure piping systems and fittings

  2. pipeline identification lists showing the maximum pressures and temperatures for each pressure piping system

  3. a list of pressure relief devices, including the set pressure

  4. material specifications, size, schedule and primary service rating of all pressure piping and fittings

  5. the welding procedure registration number

  6. the pressure pipe test procedure outlining the type, method, test media , test pressure, test temperature, duration and safety precautions

  7. a form, provided by the Administrator, completed by the engineering designer or contractor which relates to the general engineering requirements for design and field construction of pressure piping systems

  8. such other information as is necessary for a safety codes officer to survey the design and determine whether it is suitable for approval and registration

1.5. Important Questions

  1. Which Act governs the design of plant pressure piping systems in Alberta?

  2. Are process plant water lines considered pressure piping systems?

  3. For what fluid service category may a hydro test be waived per B31.3?

  4. What is the difference between a pipe elbow and a bend?

2.0 Codes and Standards

The following codes are used for the design, construction and inspection of piping systems.

2.1 The ASME B31 Piping Codes

Piping codes developed by the American Society of Mechanical Engineers:

B31.1 Power Piping

Piping typically found in electric power generating stations, in industrial and institutional plants, geothermal heating systems and central and district heating and cooling plants.

B31.3 Process Piping

Piping typically found in petroleum refineries, chemical, pharmaceutical, textile, per, semiconductor and cryogenic plants and related processing plants and terminals.

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

Piping transporting products which are predominately quid between plants and terminals and within terminals, pumping, regulating, and metering stations.

B31.5 Refrigeration Piping

Piping for refrigerants and secondary coolants.

B31.8 Gas Transportation and Distribution Piping Systems

Piping transporting products which are predominately gas between sources and terminals including compressor, regulating and metering stations, gas gathering pipelines.

B31.9 Building Services Piping