Rasberry,
Thank you for the clarification. You are correct on your description of static vs dynamic pressures. Additionally, to determine full open pressure drop, you do take into consideration both pressures.
Thanks again,
N. Miller
There are many spring loaded check valves that are non-code compliant that could be used in this type of application for vacuum or pressure relief. As to whether or not it would be allowed for your particular application is beyond my knowledge unfortunately. :(
There are some check valves that have their bodies made from bar stock instead of a casting. Check All valve is one of them I came across on a Google search.
My understanding of spring cracking pressure is that in theory you can choose just about any spring cracking pressure you want (although it is difficult to find a manufacturer that offers more than a couple spring cracking pressures). Also valve cracking pressure is the differential pressure...
gustorf,
My only other thought, would they possibly be talking about a cracking pressure verification test? All spring loaded check valves have an allowable variance + or - 20% for example. A cracking pressure verification test will tell you exactly where within that allowable range the check...
What style of compressor are you using (reciprocating, centrifugal, etc.)? Gustorf is right on with the API 598 seat leakage classifications for check valves. What size of valve are you looking at using?
nmiller127
MS323,
I would agree with moltenmetal's statement. I have long wondered what the purpose of putting a gauge with an open end would help prevent? Most of the systems I have seen are not set up to detect leakage through the rupture disk. They are only set up to show when a rupture disk has...
TrippL,
To your original question, the definition of spring cracking pressure is the differential pressure required to begin to open a valve. For instance if you have a 1.5 psi cracking pressure, the valve will begin to open up when there is 1.5 psi more pressure on the inlet side of the valve...
