Generally, for flanged valves.
1) End flanges will be according to ASME B16.5 dimensions, rating will be whatever it is. (long standing problem with all kind of material)
2) Wall thickness will be according to ASME B16.34, they may provide an ambient pressure rating.
The valve manufacture...
In a cryogenic application, it's often the problem that ice or somethings forms on the seat surface, preventing you from achieving perfect sealing. While you could feasibly specify in "zero" leakage (every valve leaks, it's how much and against what size media vs how long)
That being said, when...
how desperate are you?
ultimately, the thickness of the flange is dictated by the material and the required bolting and gasket seating stress. ASME B16.5 flange dimension and ASME B16.10 dimensions are there to allow ease of calculation, procurement, and piping assembly and design. in desperate...
you can't calculate it. closest is empirical testing / ANSYS simulation, you are not taking into consideration of any of the turbulence which comes with non fully opened gate valves. which wouldn't matter after the valve breaks.
Luke | Valve Hax | https://valvehax.com/
^ nick is right.
you don't have to. but should if you want to be, 100%
but honestly, the point of the safety factor is to prevent the drivetrain from BREAKING due to excessive force. a broken dowel pin would just allow the top flange to slip a bit, potentially making the valve leak a bit. I...
We are working on 607.. but the whole point of the fire testing is to demonstrate that a particular valve, after being in fire for 30 minutes (Average time to put out fire in refinery), can still maintain some level of control of media.. the key things on these valves is mainly the fastener...
again, use table 9. table 8 is wrong in this case.
sounds like there is a bunch of new engineer or something, many flanges made to standard dimensions will fail calculation, depending on material. this is because calculation is much more conservative. but have been historically used with no...
usually people just copy each other, do calculation to code and call it a day honestly. some company keep internal design guidelines.
otherwise, there are old valve design handbooks that can still be used, especially for calculation for non standard flange dimensions.
Luke | Valve Hax |...
ASME Section VIII Pressure Vessel Calculations can be used. but honestly, should use ASME B16.34 as the thinnest thickness, or else you probably won't meet whatever code.
Also, safety factor and defect in material should all be taken into consideration.
not to mention, the thinner a valve is...
K Anand, no one will be able to help you find what you are looking for if you can't describe what you are looking for. or what kind of application you are needing the valve to perform in.
Remember, name doesn't do much good if no one recognize it, or if it's not common.
Luke | Valve Hax |...
i should correct myself. api does not have a mandatory type test. but yes, it's an optional test. again, very difficult to actually achieve on larger valves.
Luke | Valve Hax | https://valvehax.com/
API 6D does not have a type test. However, auditor can ARGUE that you have to validate it through empirical testing.
The fact of the matter is it can be difficult (on larger size) to achieve torque values to break those stem.
Luke | Valve Hax | https://valvehax.com/
90 psig shop air is honestly, not that dangerous at all. wear some proper ppe, maybe overkill use a shield.
We test thousands of valves a day with shop air. used to even test full pressure with pneumatic pressure for class 150-300 (i stopped that) it did however catched 5 extra valves a month...
Please check note C on Table 1 of API 598, i believe MSS standard and maybe API 608 may make reference to it.
This is a touchy subject at standards writing organizations, but it's a fact. Smart end users may opt to test valve seat at 100% pressure instead of 110% to verify seat integrity...
what's your test sequence?
here is your likely issues.
1) sand, y'all got lots of sand, which can damage the seats.
2) soft seat issues, if you had the valve half open, or it was staged for a long time, the ball can be not round, causing the soft seat memory issue. there are workaround.
3)...
Your valve, with graphite packing, and ptfe seat, should be considered a decreased temperature rating valve. and not be running the high temperature tests.
However, if you look at section 11, which specifies valve qualified. you will see that the valves with the "same quarter-turn design" may...
API 641 testing doesn't care about the status of your seat after the test. Nor does it care about "differentiating" the seat material.
All it cares about is your test temperature, the packing material, the stem seal design.
However, i am not sure why you are trying to qualify a PTFE seated...
