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Shell: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specification。

Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the specification。

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Introduction

The revision of API 6D is developed based on input from API 6D Task Group technical experts。 The technical revisions have been made in order to accommodate the needs of industry and to move this specification to a higher level of service to the petroleum and natural gas industry。

This specification is not intended to inhibit a manufacturer from offering, or the purchaser from accepting, alternative equipment or engineering solutions for the inpidual application。 This may be particularly applicable where there is innovative or developing technology。

1Scope

1。1General

This specification defines the requirements for the design, manufacturing, assembly, testing, and documentation of ball, check, gate, and plug valves for application in pipeline and piping systems for the petroleum and natural gas industries。

This specification is not applicable to subsea pipeline valves, as they are covered by a separate specification, API 6DSS。

This specification is not applicable to valves for pressure ratings exceeding Class 2500。

1。2Conformance

1。2。1Units of Measurement

In this specification, data are expressed in both U。S。 customary (USC) and metric (SI) units。

1。2。2Rounding

Except as otherwise required by this specification, to determine conformance with the specified requirements, observed or calculated values shall be rounded to the nearest unit in the last right-hand place of figures used in expressing the limiting value, in accordance with the rounding method of ASTM E29 or ISO 80000-1。

1。3Conformance with Specification

A quality management system shall be applied to assist conformance with the requirements of this specification。 The manufacturer shall be responsible for conforming with all of the applicable requirements of this specification。

It shall be permissible for the purchaser to make any investigation necessary in order to be assured of conformance by the manufacturer and to reject any material that does not conform。

1。4Processes Requiring Validation

The following operations performed during manufacturing shall be validated, by the manufacturer, in accordance with their quality system as applicable: 撑开式闸阀设计英文文献和中文翻译:http://www.youerw.com/fanyi/lunwen_97242.html