【国外标准】 Standard Guide for Squeeze-Off of Polyolefin Gas Pressure Pipe and Tubing

3.1 Squeeze-off is a technique used to control the flow of gas through a pipe by the compressing action of a mechanical or hydraulic device. Squeeze-off may be used to reduce the flow of gas to an acceptable rate.3.2 Proper squeeze-off procedures result in significant time saving in the reduction of gas flow in an emergency and in the maintenance and operation, or both, of a gas distribution system. Improper squeeze-off can cause damage to the pipe or create a safety hazard, or both.1.1 This guide describes general procedures for squeeze-off of polyolefin gas pressure pipe and tubing. Pipe and squeeze tool manufacturers shall be requested to supply recommendations for squeeze-off with materials or products.1.2 Governing codes and project specifications should be consulted. Nothing in this document should be construed as recommending practices or systems at variance with governing codes and project specifications.1.3 This guide covers squeeze-off of polyolefin pipe and tubing in accordance with Specification D2513.1.4 Where applicable in this guide, “pipe” shall mean “pipe and tubing.”1.5 Units–The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units, which are provided for information only and are not considered the standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.