Hello desertfox,
My picture was not completely correct. The seal OD should be the OD of the adapter at the O-Ring groove almost directly below the bolts in question. However, I don't believe this changes your answer. It certainly does not change my understanding or interpretation.
I was...
Hello desertfox,
no problem. I tried to be clear, but sometimes these sort of things are difficult to explain in text. :)
the spec is pretty clear that it's the area bounded by the gasket. I've attached a picture of what I'm looking for. Perhaps that will help.
Thanks for the thoughts and...
Hello desertfox,
thanks for the reply.
We did some investigation here and noticed that the ASME B16.5 spec for # of bolts and their sizes very nearly meet or just exceed the calculation in B16.34, if using the full effective seal diameter area and not subtracting out the flow diameter area...
That's a good point. I am looking into this option right now as well, but I'm hoping for more of a quick answer of what others are doing when designing ball valves.
Thanks for the input!
How are others interpreting this?
Jeff
Yes, you are absolutely right. When the ball is closed, the pressure is acting over the ID of the seat seal (conservatively, the OD could be used also). However, in the case of a 3pc trunnion ball valve, the adapters have an OD that is larger than the seat seal OD. We are using the adapter...
Thanks for checking those interpretations. We have volume 4 here and I did not see anything in there either.
What are others doing in practice?
Thanks.
Jeff
Hello,
We have been engaged in a raging debate about interpretation on the calculation of Ag defined in ASME B16.34 sections 6.4.1 and 6.4.2 as it pertains to ball valves. Specifically, we are discussing section 6.4.2 and the bolts between the adapters and body. As the spec reads "Ag = area...
Yes, I agree that stresses should always be below yield. However, to my experience, the ASME allowable stresses are always less than yield, so I'm looking for some interpretation on what value to use for the MAST.
Hello,
When verifying stem MAST calculations against API 6D 6.17.1, should the ASME BPVC II pD allowable stress at temperature be used to get the "design torque" or should the yield limit of the material be used?
Any thoughts?
Interesting thought. I was also thinking that it might be the width of the sealing face of the seal against the valve. The problem is that these are only guesses... I think that the width of the sealing face (in deg) will be less than the angle between the fully closed position and the...
We just called support about this and they said that NX Nastran is "broken" (their word, not mine).
Go to http://support.ugs.com and see the announcement "Hot Issues and Announcements".
Hello,
As for a general list of consultants, I've not found a well maintained and organized list. However, I may be able to help you out, but I clearly need to discuss that outside of the forum. How can I contact you?
Jeff
Hello,
To confirm my fears, I created a simply test model that consists of one plate that I split into two collectors, to which I apply a simple tensile load. At the interface of the two collectors, the contours do not match up. All properties are the same between the two collectors. After...