Trim 8 in lieu of trim 12
Trim 8 in lieu of trim 12
(OP)
Hi there,
I'm wondering if trim 8 can be used in lieu of trim 12 for an A105-N check valve in a sour hydrocarbon service with a design temp of 294 deg C and pressure of 7832 kPA. From what I've read the only difference seems to be trim 8 uses 410SS, while trim 12 uses 316SS
Thanks
I'm wondering if trim 8 can be used in lieu of trim 12 for an A105-N check valve in a sour hydrocarbon service with a design temp of 294 deg C and pressure of 7832 kPA. From what I've read the only difference seems to be trim 8 uses 410SS, while trim 12 uses 316SS
Thanks





RE: Trim 8 in lieu of trim 12
yes, the only difference betweeen API trim 8 and trim 12 is the grade of steel;
you've probably had a look at the API 600 trim chart, where seat, disc, backseat and stem materials are defined: http://alloy-valves.com/Alloy-Valves-Product-Range/API-600-trim-chart.htm
316 is molybdenum-bearing and gives better corrosion resistance than 410, whilst 410 is a basic martenistic steel with 11.5% chromium which gives basic/sufficient corrosion coverage.
Commercially speaking, there's barely much price-difference depending on size/quantities involved.
My focus is on valve stockists in the us and uk who supply duplex and super duplex valves, and inconel and hastelloy valves, plus titanium, alloy 20 and 904L valves.
RE: Trim 8 in lieu of trim 12
Yes I've seen the trim chart, I just don't know much about metallurgy so didn't know if 410 could be used in lieu of 316. From what you're saying it seems like 316 is the better choice but 410 can be used, correct? The specs I'm using calls for 316 but my valve vendor only has 410 in stock.
RE: Trim 8 in lieu of trim 12
My focus is on valve stockists in the us and uk who supply duplex and super duplex valves, and inconel and hastelloy valves, plus titanium, alloy 20 and 904L valves.
RE: Trim 8 in lieu of trim 12
RE: Trim 8 in lieu of trim 12
RE: Trim 8 in lieu of trim 12
RE: Trim 8 in lieu of trim 12
From my experience, trim 8 cannot be used inplace of trim 12. But you can offer trim 8 to your client & see his reply.
RE: Trim 8 in lieu of trim 12
I tried to get a spec waiver approved for trim 8, with my justification being that trim 8 is certified under NACE if the PH is greater than 3.5 and the process fluid is produced vapour at a temp above 60 deg C with chlorides present (trim 8 has better resistance to chloride stress corrosion cracking). The client said it would be acceptable if the PH was proven to be greater than 3.5 but suggested the use of trim 5, 10, or 16 as better alternatives. In the end my vendor found some trim 16 valves.