This is the sixteenth edition of CSA B51, Boiler, Pressure Vessel, and Pressure Piping Code. It supersedes the previous editions published in 1997, 1995, 1991, 1986, 1981, 1975, 1972, 1969, 1965, 1960, 1957, 1955, 1951, 1945, and 1939.
In keeping with CSA’s goal of harmonizing its standards with those of other countries to the greatest extent possible, CSA’s Technical Committee on Boilers and Pressure Vessels and its subcommittees have, in the course of developing this Standard, worked closely with the National Board of Boiler and Pressure Vessel Inspectors in the USA and with the American Society of Mechanical Engineers (ASME) committees responsible for producing ASME’s Boiler and Pressure Vessel Code.
There are three parts to this Standard.
Part 1 contains requirements for boilers, pressure vessels, pressure piping, and fittings. It is intended mainly to fulfill two objectives: first, to promote safe design, construction, installation, operation, inspection, testing, and repair practices, and second, to facilitate adoption of uniform requirements by Canadian jurisdictions.
Part 2 contains requirements for high-pressure cylinders for the on-board storage of natural gas as a fuel for automotive vehicles. It has been harmonized with International Organization for Standardization (ISO) Standard 11439:2000, Gas cylinders — High pressure cylinders for the on-board storage of natural gas as a fuel for automotive vehicles. In addition, the CSA subcommittee responsible for developing Part 2 has consulted with the American National Standards Institute (ANSI) committee responsible for developing ANSI Standard NGV2-2000, Basic Requirements for Compressed Natural Gas Vehicle (NGV) Fuel Containers. The members of these two committees are dedicated to harmonizing their Standards as far as circumstances allow.
Part 3 contains requirements for compressed natural gas refuelling station pressure piping systems and ground storage vessels. These requirements have been allotted a separate part of the Standard to emphasize the differences between them and the requirements in Part 1, and thereby to facilitate their application. To ensure that the designs of new cylinders and refuelling stations are compatible, the filling limits specified in Clause 4.2 of Part 2 provide the basis for the design pressures specified in Clauses 6.1.4 and 6.1.5 of Part 3.
All three parts of this Standard have undergone technical and editorial revisions since the previous edition. Some of the more noteworthy changes are as follows:
- Designs for fittings may now be registered through a central registration process administered by a nationally recognized organization (Part 1, Clause 4.2.3).
- Manufacturers of fittings with more than one plant or facility must now submit proof of a quality control program for each plant or facility where production occurs (Part 1, Clause 4.2.4).
- Organizations wishing to repair boilers, pressure vessels, pressure piping, or fittings must now submit proof that they maintain a satisfactory quality control system (Part 1, Clauses 4.9.2 and 4.9.3).
- The informational requirements for nameplates affixed to boilers, pressure vessels, and fittings have been revised (Part 1, Clause 5).
- Part 2 contains revised requirements concerning fire protection (Clause 6.9), design changes (Clause 6.16), failure to meet test requirements (Clause 6.17), and test methods (Clause 14).
- Part 2 contains a new annex on the procedure for requalifying all-steel natural gas vehicle storage cylinders (Annex B). This annex is referenced in Part 3 as well.
The users of this Standard should note that it is a recommendatory document only and does not have the force of law except where it has been officially adopted by a Canadian jurisdiction. Users should also note that adoption does not necessarily mean that the Standard has been adopted unchanged. For example, a jurisdiction may decide to make a non-mandatory annex mandatory.
In addition, owners and users of cylinders designed to the requirements of Part 2 should note that the safe operation of such cylinders requires, first, compliance with the service conditions specified by the manufacturer, and second, use of the cylinders only during the service life specified by the manufacturer. Each cylinder is marked with an expiry date, and owners and users are responsible for ensuring that a cylinder is not used after that date.
Except as indicated in Clause 1.2, Part 1 of this Standard applies to all boilers, pressure vessels, pressure piping, and fittings, as provided for by the Act (as defined in Clause 3) and identified in Part 1 of this Standard.
1) In certain provinces there may be variations in the size limitations specified in Part 1 of this Standard. The regulatory
authority should be consulted.
2) All pressures specified in Part 1 of this Standard are gauge pressures above atmospheric pressure.
Requirements for compressed natural gas cylinders and refuelling station pressure piping systems and containers are covered in Parts 2 and 3 of this Standard.
This Standard does not apply to
a)pressure-retaining components in hydraulic elevators;
b)pressure-containment devices for gas-filled switchgear and controlgear; and
c)pressure vessels for the transportation of dangerous goods regulated by Transport Canada.
Where any clause of Part 1 of this Standard is at variance with the referenced codes and standards, the requirements of Part 1 of this Standard govern.
In CSA Standards, shall is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; should is used to express a recommendation or that which is advised but not required; and may is used to express an option or that which is permissible within the limits of the standard.
Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.
Notes to tables and figures are considered part of the table or figure and may be written as requirements.
Legends to equations and figures are considered requirements.
The values given in SI (metric) units are the standard. The values given in parentheses are for information only. Nominal pipe sizes are expressed in non-dimensional terms.