The Canadian Piping Flexibility Stress Analysis Standard


The Canadian Piping Flexibility Stress Analysis Standard. By Meena Rezkallah, P.Eng. Piping Stress Engineer. professional engineer in canada
The Canadian Piping Flexibility Stress Analysis Standard. By Meena Rezkallah, P.Eng.

The Canadian Piping Flexibility Stress Analysis Standard for a premium piping engineering & full-service pipe design and pipeline / pipe stress analysis services across Canada & globally. Using CAESAR II and pipe stress calculations as per API, ASME B31.3, B31.1, B31.8, B31.4, CSA Z662.


1.0 SCOPE

2.0 LEGISLATION, REGULATIONS, CODES AND STANDARDS

2.1 API (American Petroleum Institute)

2.2 ASME (American Society of Mechanical Engineers)

2.3 NEMA (National Electrical Manufacturers Association)

2.4 NBC (National Building Code of Canada)

2.5 CSA Group

3.0 PROCEDURE

3.1 Quality Assurance

4.0 DESIGN

4.1 Piping Systems

4.2 External Load Limits on Equipment

4.3 Allowable Forces and Moments on Flanges

4.4 Friction Effects

4.5 Supporting

4.6 Wind Loads

4.7 Seismic Loads

4.8 Vibration

4.9 Existing Lines


1.0 SCOPE

This standard prescribes the basic requirements for the engineering of piping systems and components

for thermal flexibility, support, pressure, vibration, fluid, or gas flow reactions and environmental factors,

including effects on equipment.


2.0 LEGISLATION, REGULATIONS, CODES AND STANDARDS

The publications listed below form part of this standard. Each publication shall be the latest revision and

addendum in effect on the date this standard is issued for construction unless noted otherwise. Except as modified by the requirements specified herein or the details of the drawings, work included in this

standard shall conform to the applicable provisions of these publications.


2.1 API (American Petroleum Institute)


2.2 ASME (American Society of Mechanical Engineers)

2.3 NEMA (National Electrical Manufacturers Association)

  • SM23 Part 8

2.4 NBC (National Building Code of Canada)


2.5 CSA Group


3.0 PROCEDURE


3.1 Quality Assurance


3.1.1 The practices outlined herein establish the minimum requirements to which the Piping Stress Analyst shall adhere in the performance of quality assurance activities to ensure adequate engineering review of piping systems. Pipe flexibility and stress analysis shall conform to the governing piping code. The pipe line list for the project shall be the controlling document establishing individual line parameters, with the piping drawings defining line configurations.


3.1.2 Calculations shall be retained by the Engineering Contractor or Engineering Consultant for a period of 15 years.


3.1.3 Formal computer analysis shall be performed on the following piping systems:

• Process lines to and from steam generators.

• 2 inches and larger diameter process lines to and from pumps, compressors, turbo-expanders, and blowers.

• Lines with design temperatures over 260°C.

• Piping systems that are selected by the Lead Piping Stress Engineer.

• Steam lines to and from turbines.


3.1.4 As a minimum, engineering analysis by visual inspection and short-cut manual calculations shall be performed on the following systems:

• 16 inches and larger diameter lines.

• Lines to vessels that cannot be disconnected for purging or steam out.

• 3 inches and larger diameter lines at design temperature over 150°C.

• Piping systems selected by the Lead Piping Stress Engineer, which do not require formal computer analysis.

• Relief systems, whether closed or relieving to atmosphere, with considerations for attached or detached discharge pipes.

• Vacuum lines.

• Nonmetallic piping.

• Lines subject to excessive settlement.


3.1.5 Special consideration shall be given to piping systems in the following categories:

• 3 inches and larger diameter lines subject to greater than 25 mm differential settlement of equipment, or supports.

• Lines designated as "Category M," according to ASME B31.3, shall be so identified in the line list.

• Lines subject to mixed-phase flow (liquid and vapor), and lines identified as vibrating service on the flow diagrams.

• Lines subject to external pressure by reason of vacuum or jacketing.

• Piping connected to reaction sensitive equipment.


3.1.6 Lines to be considered for analysis shall be so marked on the line list.


4.0 DESIGN


4.1 Piping Systems


4.1.1 Piping flexibility shall be obtained through pipe routing or expansion loops. Expansion loops, when installed in a horizontal plane, shall be offset vertically to clear adjacent piping whenever possible. Expansion Joints / Flexible connectors shall be used only when it is not feasible to provide flexibility by other means. Expansion joints / flexible connectors shall be marked on the P&IDs and approved by the project Owner.


4.1.2 The flexibility analysis shall consider the most severe operating temperature condition sustained during startup, normal operation, shutdown, or regeneration. The analysis shall be performed for the maximum temperature differential. The effect of minimum installation and solar temperatures shall be considered in determining the maximum temperature differential.

Note: Hydrocarbon lines within units, areas, and unit pipeways shall be considered subject to steam purge. Interconnecting pipeway lines shall not be considered subject to steam purge. Lines subject to steam purge shall be designed for the steam temperatures or the design temperatures of the line, whichever is higher. Consult the process engineer at the beginning of the job for the correct temperatures.


4.1.3 Lines to purged vessels that cannot be disconnected during purging shall be designed with sufficient flexibility to accommodate the thermal displacement of the vessel.