Needle valve selection principles

1 , the pipeline system and cryogenic medium , should use plus low bonnet needle valve .
2 , the pipeline system FCCU refinery unit , optional Needle valves lift rod .
3 , fixtures and piping systems , such as acid-base chemical systems in corrosive media , should use austenitic stainless steel , Teflon seat ring in stainless steel needle valve .
4 , metallurgical systems, piping systems or devices on the power system , petrochemical plants , urban heating systems in high-temperature medium , the choice of metal to metal seal Inconel needle valves .
5, the need for flow regulation , the choice of the worm gear , pneumatic or electric adjustment with a V -shaped opening needle valve . 6 , transmission mains oil, natural gas , it is necessary to clean the pipeline , buried in the ground and the need , use full bore , all-welded construction needle valve ; buried in the ground , choose full bore welded or flanged connections the ball valve.
7 , pipelines and storage facilities for refined oil products , the choice of needle valve flange connection .
8 , city gas and natural gas pipeline , the choice of the needle valve flange and the threaded connection .
9 , metallurgical oxygen pipeline system , should use rigorous degreasing treatment , needle valve flange connection .