Valve for reciprocating flow, >10M cycles: fairy tail?
Valve for reciprocating flow, >10M cycles: fairy tail?
(OP)
Before I enter the realm of imagination, perhaps it is good to attempt to verify that my expectations are not set too high, or the opposite.
What I'm looking for is a passive check valve which can last at least 10,000,000 operating cycles, with a maximum pressure rating up to 10 bar (145 psi), for filtered water, with a size between DN200 to DN800 (when dimension is too large, parallel placement might be an option as well). When the list of available options didn't approach zero by now, the check valve will have to deal with a variable flow rate up to 1000 m3/h (600 CFM) with minimal pressure loss and leakage, since conversation of energy is essential for operation of the system.
Would there be a suitable valve for this application, or which concept would have the highest chance on success? So far a spring loaded disc-type check valve may be an option, although I've seen no examples yet of these check valves dealing with these high amount of operating cycles. Some check valve designs did pass some certification tests for 1,000,000 cycles without any sign of wear, but no company as of yet has claimed to be able to achieve higher levels. So either I'm asking the wrong companies, or I'm asking something infeasible (read: something which has yet to be engineered
).
Any thoughts on this matter?
What I'm looking for is a passive check valve which can last at least 10,000,000 operating cycles, with a maximum pressure rating up to 10 bar (145 psi), for filtered water, with a size between DN200 to DN800 (when dimension is too large, parallel placement might be an option as well). When the list of available options didn't approach zero by now, the check valve will have to deal with a variable flow rate up to 1000 m3/h (600 CFM) with minimal pressure loss and leakage, since conversation of energy is essential for operation of the system.
Would there be a suitable valve for this application, or which concept would have the highest chance on success? So far a spring loaded disc-type check valve may be an option, although I've seen no examples yet of these check valves dealing with these high amount of operating cycles. Some check valve designs did pass some certification tests for 1,000,000 cycles without any sign of wear, but no company as of yet has claimed to be able to achieve higher levels. So either I'm asking the wrong companies, or I'm asking something infeasible (read: something which has yet to be engineered
Any thoughts on this matter?





RE: Valve for reciprocating flow, >10M cycles: fairy tail?
Beyond filtering, the chemical composition of the water, and any contaminants therein, can have a strong effect on the service life of any moving/sliding/rotating components.
Is it always the exact same water, or is there a continuous supply of new contamination and oxygen as the water flows?
How many truckloads of such valves will you be needing each year for how many decades?
Mike Halloran
Pembroke Pines, FL, USA
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
If we're going to need yearly deliveries of several truck loads, we would have a serious problem :). A valve rated for 1,000,000 cycles would only last months, which is why I'm curious to see if it is feasible to achieve (much) higher operation cycles.
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
As others have indicated, your optimism regarding number of cycles might be 'a bit' high. Regarding minimum loss you should have a look a 'non slam nozzle check valve' Erhard or similar from other producers. My personal experience is that this is a high-quality valve with long standtime.
http://f2557522.td-fn.net/wp-content/uploads/2014/...
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
Is it indeed common to replace check valves with reciprocating flows annually/quarterly after, let's say, 1,000,000 cycles, or are higher reliability levels already achievable (from your experience)?
One of the options I have been considering is this axial check valve from Mokveld (http://www.mokveld.com/upload/product_document/Mok...), which looks in principle quite similar to the design of your suggestion, due to its relatively fast closing times and low pressure drop, as well as robustness of the design. Thank you very much for the suggestion, I will also attempt to contact them to see if they could provide a (rough) estimate for the number of operating cycles, so we can calculate how many truck loads of valves we need to order on a yearly basis :(.
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
Hello, TwoZero!
Mokveld is one of the other well-renowned companies producing valves based on this principle.
I would advise you to try to describe each application you have with a minimum. maximum and medium flow, pipeline dimension (note: valve dimension might be suggested different with cone or abrupt reduction (as suitable for the situation) from the valve producer.)
Also try to describe cycles/use per time unit and operational periodes. Also orientation of valve and flow and free pipeline before and after the valve will be relevant. Best and separate support of pipeline with separate support of the valve is a must for minimum wear.
A good supplier or producer will first on this basis be able to advice on life-time.
I will also recommend you to carefully study the factory's (general) data on pressure loss. I see this is not included in the general brochure from Mokveld, but surely available from the factory if you give the correct necessary input.
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
What exactly is your definition of reciprocating here?
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
Can see your reasoning for quick closure on this check valve, hence the idea to use a few smaller check valves lined up in parallel to enable quicker closing than a single DN800 check valve. Talk to a rotating machinery engineer about measures on the pump motor to prevent reverse rotation or minimise the effects from it. These check valves should be located on a horizontal piping run to enable maximum possible turndown on flow. Presume this pump is on a VFD drive to save on power demand? You may need an automated startup recirc line on pump discharge to minimise starting torque? If you have one, then you could use this during pump auto stop sequence to further reduce the severity of service on this check valve when the pump is coasting down to stop.
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
The pipe dimension will be about 600 mm, with a flow rate from 50 m3/hr to 1000 m3/hr and anything in between. The average cycle time for each valve is 15 seconds, or 6000 operations per day, 2,100,000 operations per year. The maximum pressure on the valve never exceeds 10 bar. Arguably, it may be preferable to have several long-lasting smaller valves than one DN600 / DN800 check valve. Whether this means I could use tens or hundreds of 1" valves which may last 100,000,000 cycles, some DN100 valves, or something else, I'm still not sure and will depend largely on the energy loss of the specific solution and lifetime, which is essential in this story.
That the small ball check valves in a triplex pump are actually capable of withstanding these very long duty cycles in harsher environments is actually quite promising. So far, I understand that the shear dimension of the valve is severely limiting the lifetime, so, an interesting point to raise would be if it were beneficial, both from the perspective of energy loss and operational lifetime, to replace the large valves by several smaller valves.
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
Noreva has installed some 500 valves (6in) in 2004 that have seen 1 Mio cycles annually.
Feel free to contact Noreva for Details.
RE: Valve for reciprocating flow, >10M cycles: fairy tail?
Seems that your dimensions for the valve have been selected after normal (conservative) flow in the pipeline, DN 600 will after my calculations give a speed of 3,5 m/s at 1000m3/h and 0,05 m/s at 50m3/h. The lowest flowspeed could give problems for most checkvalves.
Both regulating valves and checkvalves should for more complicated applications be selected after operating flow conditions suitable for the valve, not pipeline flow.
If you look at the standard allowable flow for a good designed non-slam nozzle check valve, allowable standard speed goes up to 5 m/s, and I know of cases where the factory has given OK for around 7m/s. My experience is with Erhard Non-slam nozzle check-valves, but you may also check others mentioned above (Mokveld, Nereva).
Have a look at my previous advice regarding as exact as possible operating specifications for the flow, contact the factories and check if you can go down to 500mm (should only improve performance at 5,1 and 0,07 m/s) or even down to 400mm (7,9 and 0,1 m/s). I have not checked if any producer can give you 450mm. Downsizing will also of course get the cost of the valves down.
A more complicated solution would be to split the operation to two parallell valves, one small and one larger as done with increasing flow/pressure for overflow valves. The split would have to be done mechanically by opening of the larger checkvalves inlet by increasing flow. An alternative would be to check if a stronger spring (larger operating opening pressure for the largest valve) could solve the split operation. Flow loss to be checked for all operation conditions.