17-4 PH SS material for valve stem
17-4 PH SS material for valve stem
(OP)
Hi All,
i have designed choke valve.
As per NACE MR 0175-2009. in table A.27, i can not use 17 -4 PH ss material for body and bonneet,
i am going to use for valve stem . but i am little confuse for that . can i use 17-4 PH ss for ste, or not?
ragards
Kamlesh
i have designed choke valve.
As per NACE MR 0175-2009. in table A.27, i can not use 17 -4 PH ss material for body and bonneet,
i am going to use for valve stem . but i am little confuse for that . can i use 17-4 PH ss for ste, or not?
ragards
Kamlesh





RE: 17-4 PH SS material for valve stem
RE: 17-4 PH SS material for valve stem
Erkamal
You can use 17-4 from table A.27 if you design input meets the guidelines of table A.27.
Petrotrim Services, LLC
www.petrotrim.com
RE: 17-4 PH SS material for valve stem
As for using 4130 for any part of a valve, I wouldn't recommend that either. Any sealing surface that isn't overlaid will have a short life. Also, although 4130 has no defined "limit" at which cracking becomes a concern (provided all NACE hardness, etc. requirements are met), general corrosion would become a concern in plenty of situations.
RE: 17-4 PH SS material for valve stem
maybe I'm just old school, but there must be several hundred thousand API 6A valves, chokes, and X-Mas trees in service in NACE and mildly corrosive service for the last 50 years. Only recently, with the advent of various injection chemicals and higher temperature service conditions has interest in CRA cladding become prevalent. Many customers disallow 17-4 as stem materials, requiring one of the Ni alloys. Just go with it, the costing isn't that much higher these days.
Rick
RE: 17-4 PH SS material for valve stem
i.e.:- Here is standard for (EE class & temp.-U) Body and Bonnet AISI 4130 material.Needle material PH 17-4 SS & Hard alloy on stem tip.And orifice/Bean/seat form pressure dope 1500 use SS 316,pressure drop +2000 use tungsten carbide.
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