Preface
This is the fourth edition of CSA B356, Water pressure reducing valves for potable water distribution systems. It supersedes the previous editions, published in 2010, 2000, and 1979 under the title Water pressure reducing valves for domestic water supply systems.
This Standard is intended to promote the development of uniform regulations in Canada pertaining to the requirements for water pressure reducing valves.
The major changes to this edition include
a) adding 1/4, 3/8, and 4 in devices;
b) adding Clause 4.1.2 for lead content;
c) revising valve construction material requirements;
d) revising the minimum reduced flowing pressure test; and
e) updating marking requirements.
This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard.
This Standard was prepared by the Technical Committee on Backflow Preventers and Water Pressure Reducing Valves, under the jurisdiction of the Strategic Steering Committee on Construction and Civil Infrastructure, and has been formally approved by the Technical Committee.
This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group.
Scope
1.1 General
This Standard applies to self-acting spring-operated devices that automatically reduce the initial pressure in water systems to a set lower pressure. It applies to devices that are of the direct-acting diaphragm type with a means for adjusting the pressure setting. Valves can be with or without an integral bypass relief valve or strainer.
1.2 Sizes
This Standard applies to nominal device sizes of 1/4, 3/8, 1/2, 3/4, 1, 1-1/4, 1-1/2, 2, 2-1/2, 3, and 4 in (DN 8, DN10, DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, and DN100).
1.3 Requirements
This Standard provides requirements for material specifications, construction, structural integrity tests, capacity, reduced pressure deviations, instructions, and marking.
1.4 Terminology
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.
Annexes are designated normative (mandatory) or informative (nonmandatory) to define their application.
1.5 Units of record
The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.
