Quality assessment


Flange inspection standards and methods

 

Standard System

International pipe flange standards are mainly divided into two systems: one is the European pipe flange system represented by the German DIN; the other is the American pipe flange system represented by the American ANSI pipe flange. In addition, there are Japanese JIS pipe flanges, which have less international influence.

Therefore, the international flange standards are classified as follows:

1. European system pipe flanges represented by Germany and the former Soviet Union

2. American system pipe flange standard, represented by ANSI B16.5 and ANSI B 16.47

3. British and French pipe flange standards, each of which has two sleeve flange standards.

 

In addition, my country must follow the following table standards and specifications:

HG/T 20592-2009 Standard for Steel Pipe Flanges

HG/T 20615-2009 Steel Pipe Flanges (Class Series)

 

Test method

 

       Appearance Inspection:The casting surface should be smooth and free of forging scratches, cracks, etc. . The sticky sand and oxide scale on the casting surface should be removed, and no defects (such as cracks, shrinkage holes, slag inclusions, etc.) that affect the performance of the casting are allowed.

        Machined surfaces must be free of burrs, detrimental scratches and other defects that reduce flange strength and connection reliability.

       The sealing surface of the ring connection face flange should be checked one by one, and the two sides of the groove should not have surface defects such as cracks, scratches and bumps caused by machining.