We use an empirical formula as an indication of the final friction force in needle valves. The result is always pessimistic than the output from the prorotipe test.
F = Q * µ
Where:
F = friction
Q = load normal to the contact surface
µ = frictional coefficent - for graphite of polished steel...
I hade exactly the same concern with mechanical rotary seals.
You are right: the gasket does not make the valve fire safe. It depends on the design of the valve and also on the material used for the gaskets.
The scope of API 6FA is "..to establish the requirements for testing and evaluating...
Never happened.
Pneumatic test can be used as alternative of hydro test only if done as required by ASME B31.1 par. 137.5
But Pneumatic tests are potentially more dangerous than hydrostatic so you must to go through a adequate risk assessment.
Low pressure test is done as a means of locating...
Hi.
I personally had experience in many commissioning of natual gar tratment plant for power stations.
Before to test hydrostatically the piping welded on field we usually made a low pressure test using air at maximum 6 bar increasing pessure in step of 2 bar with a leak check on weldings on...
I'm searching information about High pressure stainless steel tubing.
I mean tubing with a maximum working pressure from 15kPSI to 60kPSI and a OD/ID ratio from 1.5/1 to 3/1.
I went through the main manufacturers of this tubing searching for information about code of calculation without...
Is a no-no to put in a pipeline a component whith flanges having different pressure rating than those of the system in which it is assembled. Even if the rating of component is greater than the line.
If this where allowed so we could use only 3 pressure ratings (300-900-2500) and than flange...
Assumend that MOV is the acronym of Motor Operated Valve and ROV means Remote Operated Valve.
While ROV ia s generic term used to indicate an actuated (pneumatic, electric, hydraulic or other) valve which may be opened or closed from a distance by means of electric signal, MOV indicates a valve...
Hello everybody!
We are currently writing some “white paper” regarding manifold and instrument valves and we are searching for information about their history, operation, final application etc.
Surfing on internet is very hard to find such information. No one has indication about how to choose...
Ok, now I start to understand!
But my problem now is that I'm working with pipes MAWP from 10Kpsi to 60Kpsi and a t>D/6
If I got right I shall use ASME B31.3 chapter IX par. K304.1.2 for wall thikness calculation (or MAWP)
Is Paragraph 304.2.1 still applicable? No longer I think...
Hello everyone!
We are facing a new challenge in our company.
We are manufacturer of high pressure equipments from 15Kpsi to 60Kpsi included valves and fittings.
We also deal with high pressure tubes from 1/4" to 1" o.d. 316 high strenght material (usually 100.000PSI 700N/mm2 Rp 0.2 minimum)...
Hi
What do you mean with PTFE doby seal? Do you mean the gasket between body and closure? No rubber (FKM or NBR ORings) ?
Which internal bores are you searching for?
Regards
Daniel
Hi!
Usually the manufacturers indicate on the needle valves the direction of flow which must follow the fluid.
Generally, the fluid is conveyed from under the shutter, passes into the chamber of the bonnet and then exit.
But can the needle valves be used in the opposite direction? What there...
Hi,
My complete question is: can ASME Section VIII Div.1 UG27 be used for ball valves body w.t. calculation instead of ANSI B16.34?
Actually I would like to understand the difference between the two calculation formulas and why at the same pressure, temperature and material the two codes give...
