Common check valve problems include noise (water hammer), vibration, reverse flow, sticking, leakage, missing internals, component wear, or damage. However, it is worth mentioning that normally the real cause is the wrong style check valve for the application. In such cases, the problem is the application, not the check valve. Series BR 8.0mm Reverse Check Valve. Flow orifice restrictor, check valve manufacturer. Many sizes, pressures, SS construction. Proven one-piece flow restrictor. Easy install, fewer errors.
Reverse Flow
Reverse Flow
We are looking at a reverse flow case. Normally liquid CO2 flows through a reciprocating pump, then is combined with vaporized CO2, the combination is a vapor. A PHA team found a potential source of overpressure on the suction side of the pump should the pump be shut down. We are modeling the reverse flow case by assuming an orifice at the PD pump.
Referring to the attached sketch, I am looking at three cases. In case 1, at the beginning of the scenario, liquid CO2 will flow back from C to B through the 'orifice' and relieved at A. Skipping to case 3, in the later portion of the relief after the liquid had been removed the system will be filled by vapor, hence D to B. The relief from both are OK.
It is case 2 that I am interested in gaining input. Assuming for a minute that we have 'plug' flow through the system, consider the situation wherein there is vapor at point B, and liquid from B to A. I am thinking that as the vapor pushes the liquid ahead of it, I must handle the volumetric rate of liquid that would be displaced by the vapor (not the mass rate). I.e., I am assuming that if the volumetric rate of vapor through the orifice is 250 cfh, then I must relief 250 cfh of liquid.
How have you handled this 'vapor pushing liquid' in the past?
On a separate note, how do you deal with reverse flow through a reciprocating piston pump - is this considered a viable scenario?
Thanks
Referring to the attached sketch, I am looking at three cases. In case 1, at the beginning of the scenario, liquid CO2 will flow back from C to B through the 'orifice' and relieved at A. Skipping to case 3, in the later portion of the relief after the liquid had been removed the system will be filled by vapor, hence D to B. The relief from both are OK.
It is case 2 that I am interested in gaining input. Assuming for a minute that we have 'plug' flow through the system, consider the situation wherein there is vapor at point B, and liquid from B to A. I am thinking that as the vapor pushes the liquid ahead of it, I must handle the volumetric rate of liquid that would be displaced by the vapor (not the mass rate). I.e., I am assuming that if the volumetric rate of vapor through the orifice is 250 cfh, then I must relief 250 cfh of liquid.
How have you handled this 'vapor pushing liquid' in the past?
On a separate note, how do you deal with reverse flow through a reciprocating piston pump - is this considered a viable scenario?
Thanks
Normally Closed Check Valves 1/2' - 1'
Series CKM A unique, patented diaphragm provides normally-closed operation with a bubble-tight seal, even with no reverse pressure. 1/2″ through 1″ pipe sizes.
Product Data Sheet Dimensional Drawing, PVC/CPVC/PP/PVDF Dimensional Drawing, PTFE Installation & Maintenance Instructions Normally Closed Check Valves 1 1/2' - 4'
Series CKS An encapsulated spring and sliding poppet provides the same normally-closed, bubble-tight performance in larger sizes 1 1/2” through 4″.
Product Data Sheet Dimensional Drawing Installation & Maintenance Instructions Seal Kit Instructions Low Pressure Check Valves
A specialty diaphragm check valve that opens with virtually no forward pressure. However, Series CKD requires a minimum back pressure of 1/2 PSI to close. When inlet pressure is sensed the sealing disc is pushed off the valve seat opening the valve. In this position the sealing disc is supported internally allowing the valve to operate under high flow conditions with relatively no force or stress on the disc.
1/4″ and 1/2″ sizes in PVC, Natural Polypro, PTFE or PVDF.
Product Data Sheet Dimensional Drawing Installation & Maintenance Instructions