scope:

PREFACE

This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance for gas appliance pressure regulators. It is the result of years of experience in the utilization of gas, supplemented by extensive research.

Nothing in this standard is to be considered as in any way indicating a measure of quality beyond compliance with the provisions it contains. It is designed to allow compliance of gas appliance pressure regulators, the construction and performance of which may exceed the various provisions specified herein in any respect. In its preparation, full recognition has been given to possibilities of improvement through ingenuity of design. As progress takes place, modifications may become necessary. When they are believed desirable, recommendations should be forwarded to the Chairman of Accredited Standards Committee Z21, 8501 East Pleasant Valley Road, Cleveland, Ohio 44131.