From: "Saved by Windows Internet Explorer 9" Subject: Welding Procedure Specification - Wikipedia, the free encyclopedia Date: Tue, 7 Feb 2012 04:04:26 +0800 MIME-Version: 1.0 Content-Type: multipart/related; type="text/html"; boundary="----=_NextPart_000_0000_01CCE54D.9505F5A0" X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18463 This is a multi-part message in MIME format. ------=_NextPart_000_0000_01CCE54D.9505F5A0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Location: http://en.wikipedia.org/wiki/Welding_Procedure_Specification =EF=BB=BF
A Welding Procedure Specification (WPS) is a formal document=20 describing welding procedures. = The purpose=20 of the document is to guide welders to the accepted procedures so that=20 repeatable and trusted welding techniques are used. A WPS is developed = for each=20 material alloy and for each welding type used. Specific codes and/or = engineering=20 societies are often the driving force behind the development of a = company's WPS.=20 A WPS is supported by a Procedure Qualification Record (PQR or WPQR). A = PQR is a=20 record of a test weld performed and tested (more rigorously) to ensure = that the=20 procedure will produce a good weld. Individual welders are certified = with a=20 qualification test documented in a Welder Qualification Test Record = (WQTR) that=20 shows they have the understanding and demonstrated ability to work = within the=20 specified WPS.
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The following are definitions for WPS and PQR found in various codes = and=20 standards:
According to the American=20 Welding Society (AWS), a WPS provides in detail the required welding = variables for specific application to assure repeatability=20 by properly trained welders. The AWS = defines welding=20 PQR as a record of welding variables used to produce an acceptable test = weldment=20 and the results of tests conducted on the weldment to qualify a Welding=20 Procedure Specification.
The American=20 Society of Mechanical Engineers (ASME) similarly defines a WPS as a = written=20 document that provides direction to the welder or welding operator for = making=20 production welds in accordance with Code requirements.[1]=20 ASME also defines welding PQR as a record of variables recorded during = the=20 welding of the test coupon. The record also contains the test results of = the=20 tested specimens.
In Europe, the European=20 Committee for Standardization (CEN) has adopted the ISO standards on = welding=20 procedure qualification (ISO 15607 to ISO 15614) and on welder = qualification=20 (ISO 9606), with the exception of qualification for steel welders, where = a new=20 version of the old European EN 287-1 standard still applies. EN ISO = 15706=20 defines a WPS as "A document that has been qualified by one of the = methods=20 described in clause 6 and provides the required variables of the welding = procedure to ensure repeatability during production welding". The same = standard=20 defines a Welding Procedure Qualification Record (WPQR) as = "Record=20 comprising all necessary data needed for qualification of a preliminary = welding=20 procedure specification".[2]=20 In addition to the standard WPS qualification procedure specified in ISO = 15614,=20 the ISO 156xx series of standards provides also for alternative WPS = approval=20 methods. These include: Tested welding consumables (ISO 15610),=20 Previous welding experience (ISO 15611), Standard welding=20 procedure (ISO 15612) and Preproduction welding test (ISO = 15613).
In the oil and gas pipeline sector, the American Petroleum Institute = API 1104=20 standard is used almost exclusively worldwide. API 1104 accepts the = definitions=20 of the American Welding Society code AWS A3.0.[3]