CSA ANSI NGV 4.7:20 PDF

CSA ANSI NGV 4.7:20 PDF

Preface:

This is the first edition of CSA/ANSI NGV 4.7, Automatically pressure operated valves for natural gas dispensing systems.

This Standard encompasses the safe operation, substantial and durable construction, and performance testing of components for automatically pressure operated valves for natural gas dispensing systems, within limitations given below and in the scope of this Standard.

This Standard is based on proven engineering principles, research, and the combined expertise of gas utilities, manufacturers, users, and others having specialized experience.

Nothing in this Standard is to be considered in any way as indicating a measure of quality beyond compliance with the provisions it contains. It is designed to allow compliance of products which may exceed that specified in the provisions herein. In its preparation, full recognition has been given to possibilities of improvement through ingenuity of design. This Standard is subject to revision as further experience and investigation may show it is necessary and desirable.

Users of this Standard are advised that the devices/products/activities within its scope might be subject to regulation at the federal, state, provincial, or local levels. Users are strongly urged to investigate this possibility through appropriate channels. In the event of a conflict with this Standard, the federal, state, provincial, or local regulations should be followed.

This Standard does not apply to fuel system components that will be incorporated during original manufacture of motor vehicles which comply with Federal Motor Vehicle Safety Standards (FMVSS) or Canadian Motor Vehicle Safety Standards (CMVSS) for Natural Gas Powered Vehicles.

CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of Natural Resources Canada.

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.

This Standard has been approved by the American National Standards Institute (ANSI) as an American National Standard.

Scope:

1.1 Types of valves in the scope of this Standard

The requirements of this Standard apply to automatic valves used in compressed natural gas dispensing systems as specified in Table 1

Included:

• Pneumatically actuated — ball, needle/globe valves
• Excess flow valves
• Diaphragm valves
• Dome load valves
• Emergency shutdown (ESD) valves

Excluded:

• Electrically actuated valves (Note: Refer to UL 429, UL 1203, CSA C22.2 No. 139, or equivalent safety levels)
• Hydraulically actuated valves (Note: Not utilized in NGV fueling).
• Pressure relief valves
• Pressure regulating valves

1.2 Terminology

In this Standard, “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 (non-mandatory) to define their application.

1.3 Units of measure

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.