Explain the micro resistance slowly-closing check pneumatic valve standard 2)

the design and manufacturing: API, APID, JB/T
structure length: API, APID, DIN, JB/T
, pressure and temperature rating: SNSIB. , DIN, GB/T, HG, HG, SH, JB/T
, testing and inspection: API, JB/T
, pipe flanges: JB/T? GB / T ! Standard: HG? 、SH ANSIB。 ,喧嚣? ，GB/T，API，ASMEB.