5 replies to this topic

[djack77494]

Jabu,
I think you are asking what would be involved in upgrading the pump so that it would be capable of operating at the new (higher) discharge pressure. Since the original operating pressure [3611 kPa] and the new discharge pressure [4200 kPa] are (I believe) both less than the pump's design pressure [4500 kPa], the pump can be operated at the higher discharge pressure without fear of exceeding the pump casing's design pressure. Thus the pump should not explode. However, that is not to say that all components of the pump will be able to perform at the new conditions. Specifically, the motor will probably have been sized for the original (lower) operating pressure, and may not be able to supply the power needed at the higher pressure.

Hope that helps,
Doug

[Art Montemayor]

Jabu:

I believe Doug has the correct interpretation of your query. If he doesn't, please advise us of the correct details over what you consider "upgrading" your piston pump.

Ramesh's statement about the discharge pressure depending on the discharge opening or restictions is not a correct statement. Piston pumps will pump to defeat a pressure constraint on their discharge and this constraint is usually one of two things: a pressure regulator (or a manual discharge valve), or the target system pressure itself. The latter is the safest and the most process-wise method to use since it complies with furnishing the target system a metered quantity of fluid at the pressure it finds itself at - and this is done without causing an over-pressure on the pump's discharge due to a failed regulator or a blocked throttle valve. A piston pump will continue to pump until it either defeats the flow constraint, or it destroys itself or its driver is shut down. Hopefully, the driver's failure will occur and save the pump.

Doug's analysis is right on target as engineering logic. Luiz is correct in going to the rpm increase since this is usually the cheapest and fastest way to pump more fluid - but it won't necessarily cause more pressure to be developed and the driver will have to be looked at as Doug mentions. That is why you must be specific in telling us what you mean by upgrade: more flow capacity or more discharge pressure - or both?

Of course, I believe that we all assume you have a well-maintained and aligned pump that isn't leaking through its valves or elsewhere (like through the plunger (or piston) or throught the packing. You tell us, because we need the information in order to stop guessing what you have and what you mean.

Art Montemayor
Spring, TX