GB/T 12621-2008Standard test method for stress relaxation of gaskets for pipe flanges (English PDF)

Foreword

This standard is GB/T 12621-1990 "pipe flange gasket stress relaxation test method" amendment, and GB/T 12621-1990 Compared to the main changes are as follows:

--- The scope of the standard was amended to increase the non-asbestos rubber gasket, PTFE gasket, expanded or modified polytetrafluoroethylene Ene gaskets, flexible graphite gaskets, non-metallic coating layer having a toothed metal, corrugated metal and metal gasket wave tooth;

--- Test Method A, the strip specimens from the original sample to sample a ring;

--- Test Method B, with respect to the increase in the gasket type, the corresponding increase in supplementary test load and test temperature and so forth;

--- Increased the number of tests and test content reporting requirements. The Standard Annexes A and B are normative appendix. From the date of implementation of this standard, instead of the GB/T 12621-1990. The standard proposed by China Machinery Industry Federation. This standard by the National Standardization Technical Committee pipe accessories. This standard was drafted. Nanjing University of Technology, the machine Productivity Promotion Center, Zhejiang Cathay Pacific sealing materials Co., Ltd., Ningbo-day To Xinyuan Sealing Technology Co., Ltd., Ningbo born seals Limited, National Non-metallic mineral products Quality Supervision and Inspection Center, CHINA the University. The main drafters of this standard. Gu Boqin, Li Junying, Wu Yimin, Cairen Liang, Yuan Yilin, Li root row, Chen Ye, Mei Feng, Lei Jianbin. This standard replaces the standards previously issued as follows:

--- GB/T 12621-1990. Pipe flange gasket stress relaxation test methods

1 Scope

GB/T 12621-2008 is the Chinese national standard on standard test method for stress relaxation of gaskets for pipe flanges, in the field of fluid systems and general-purpose components. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 7 May 2008 by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China; Standardization Administration of China, and has been in force since 1 November 2008. Classification: ICS 23.040.60, CCS J15. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This standard specifies the pipe flange gasket stress relaxation of the A, B two test methods. Test Method A suitable asbestos rubber gasket, non-asbestos rubber gasket, PTFE gasket, expanded or modified polytetrafluoroethylene pad Sheet, flexible graphite gasket. Test Method B is suitable for spiral wound gasket, metal jacketed gasket, PTFE-coated gaskets, non-metallic coating layer having a gold tooth Genera, and corrugated metal gasket metal wave tooth. This method also applies to Test Method A applies gasket, metal flat gasket may also refer to This method.

2 Test Method A

2.1 Test apparatus Test on a dedicated stress relaxation test apparatus, device consists of upper and lower circular plate, center bolt, push rod, washers, nuts and dial gauge And its components and other components, as shown in Fig. Upper and lower circular plate, center bolt, push rod, washers and nuts or performance therewith shall 42CrMo When the material. Calibration central bolt in accordance with Appendix A requirements. 1

--- up and down round plate; 2

--- center bolt; 3

--- dial gauge components (including connection sleeve, the plunger and fixing screws); 4

--- dial gauge; 5

--- samples. Figure 1 is applied to the gasket stress Test Method A relaxation test apparatus