Navigating ASME B16.34
Navigating ASME B16.34
(OP)
Hi,
I'm a trainee engineer in the oil & gas industry.
I was wondering, if i have a valve with valve body = 'LTCS', Seat and Disc = 'Duplex 22% Cr'. Which material do i use when determining the class of valve (special or standard) in B16.34 Table 2?
I'm a trainee engineer in the oil & gas industry.
I was wondering, if i have a valve with valve body = 'LTCS', Seat and Disc = 'Duplex 22% Cr'. Which material do i use when determining the class of valve (special or standard) in B16.34 Table 2?





RE: Navigating ASME B16.34
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Navigating ASME B16.34
Basically i've been asked what the NDE requirements are for a valve. I've checked the datasheet to see what materials the valve is constructed from (as above post). However when I check ASTM B16.34 to find out if the valve is special or standard (to determine NDE requirements) i'm not sure whether I should be checking against the body or seat materials.
RE: Navigating ASME B16.34
(B16.34 covers flanges larger than 24" NPS)
This question might be better answered if posted in the eng-tips Valve forum......
You may find your answer in this superb magazine.....
http://www.valvemagazine.com/
MJCronin
Sr. Process Engineer
RE: Navigating ASME B16.34
RE: Navigating ASME B16.34
A valve is not special or standard until the NDE extent has been done - and not the other way around.
Does that make sense?
(MJCronin - you're thinking of B16.47 - B16.34 is the right specification for this discussion).
RE: Navigating ASME B16.34
TGS4- I hadn't realised this. I thought the type of valve, standard or special, depended what level of NDE you perform. Maybe i was going about this the wrong way. The steps i took were as follows:
1. Check max design temperature and pressures of the valve
2. Check materials of construction (I used the valve body as governing mat'l, but wasn't sure hence the thread)
3. Check rating
4. In B16.34, table 2 - Read across from temperature and down from rating to make sure max design pressure was less than the figure in the table
5. Pressure was below that in the 'Standard' table therefore I concluded the valve had no specific NDE requirements.
RE: Navigating ASME B16.34
*Determined what level of NDE you perform
RE: Navigating ASME B16.34
So, check the markings on the valve first.
You are correct though that the valve body (think of it as the pressure-retaining part) governs the material Group.
RE: Navigating ASME B16.34