JWeak
Mechanical
- Oct 26, 2011
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Is there a need for a pump to privide fexible expansion coupling in suction and its discharge. What are the parameters should I consider in providing this flexible coupling.Tnx
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Pump Flexible Coupling
- Thread starter JWeak
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In general, you should not install flexible expansion couplings. However, the need for flexible expansion couplings depends somewhat on how your piping is arranged.
Generally, you do not want to place piping stress on the pump structure because the pump is not designed for external loads from the piping. The pipe should be supported independently from the pump.
However, there may be some problem piping arrangements where flexible expansion joints may be helpful as noted in the attached article.
Generally, you do not want to place piping stress on the pump structure because the pump is not designed for external loads from the piping. The pipe should be supported independently from the pump.
However, there may be some problem piping arrangements where flexible expansion joints may be helpful as noted in the attached article.
QualityTime
Civil/Environmental
You ahould never install flexible expansion couplings especially on the discharge side of the pump. You get unbalanced forces and the pump will move...and I have seen it!!!. Bolted flanged arrangements are the best. Bolted or welded pipe make all forces balanced. I had to advise that this was to case to one of the biggie engineering firms. They eventually agreed with what I was saying and my solution
MikeHalloran
Mechanical
I don't doubt that you've seen a pump equipped with expansion couplings move, but the expansion couplings didn't cause the movement, they allowed it to happen in the presence of unbalanced forces that would still be present with a rigid piping system.
Mike Halloran
Pembroke Pines, FL, USA
Mike Halloran
Pembroke Pines, FL, USA
If using a flexible coupling on a pump discharge, it must be restrained by thru' bolts or similar so that the thrust being developed by the flex coupling is not transmitted onto the pump discharge flange. Depending on the coupling type and discharge pressure enormous thrust can be developed sufficient to push the pump off-the-base-plate.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
Pipe strain may be absorbed by a flexible pipe coupling. However the flexible pipe coupling must be properly installed. Installing a flexible pipe coupling in the line without any support will not achieve anything.
The most effective use of a flexible pipe coupling is to anchor the end of the coupling closest to the item you want to protect.
If you want to protect the pump from movement of the piping, then anchor the end of the flexible coupling that is closest to the pump. This will allow the piping strain to be absorbed by the pipe coupling, but the flange on the pump side of that coupling is anchored, therefore no strain is being passed to the pump.
Should you desire to protect the piping from movement of the pump, the you must anchor the end of the flexible coupling closest to the piping. This will allow expansion of the pump flange to be absorbed by the pipe coupling, but the flange on the piping side of the coupling is anchored so that the strain is not passed to the piping.
Flexible couplings are not a cure for a poorly designed and installed pump system. A properly designed and installed pump system will not make a pump move wether there are flexible couplings installed or not.
Refer to the attached installation instructions.
The most effective use of a flexible pipe coupling is to anchor the end of the coupling closest to the item you want to protect.
If you want to protect the pump from movement of the piping, then anchor the end of the flexible coupling that is closest to the pump. This will allow the piping strain to be absorbed by the pipe coupling, but the flange on the pump side of that coupling is anchored, therefore no strain is being passed to the pump.
Should you desire to protect the piping from movement of the pump, the you must anchor the end of the flexible coupling closest to the piping. This will allow expansion of the pump flange to be absorbed by the pipe coupling, but the flange on the piping side of the coupling is anchored so that the strain is not passed to the piping.
Flexible couplings are not a cure for a poorly designed and installed pump system. A properly designed and installed pump system will not make a pump move wether there are flexible couplings installed or not.
Refer to the attached installation instructions.
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