Pumping High Vapor Pressure Hydrocarbon Condensated
Pumping High Vapor Pressure Hydrocarbon Condensated
(OP)
I am having troubles trying to find a pump with a very low NPSH/NPSP that will transfer (or be used as a booster) hydrocarbon condensate with a vapor pressure of 14.46 psi-a, being the local atmospheric pressure 14.5 psi; from an atmospheric tank to a 100 psig transfer line.
Does any one have a good tip?
thanks
Does any one have a good tip?
thanks





RE: Pumping High Vapor Pressure Hydrocarbon Condensated
Also, what's your flowrate? The higher the flowrate, the higher the NPSHR is likely to be of any pump you put into service.
RE: Pumping High Vapor Pressure Hydrocarbon Condensated
In any case, You may need a verticle can pump if nothing else to get the head.
check on Afton pumps
RE: Pumping High Vapor Pressure Hydrocarbon Condensated
The flow rate is aprox 5gpm (batch, so it can be defined a flow of 4 or 6gpm), the NPSHa=0.3ft, keeping a LLL in the tank of 1ft (taking out losses, adding the differential head due to the elevation of the tank)
The Condensate has this properties:
Sg: 0.6641
Density: 0.6987 g/cm3 @ 60F
Vapor Press: 14.46 psi-a
it condensates on the line that goes to the flare, and drain to the tank (with water). When there is water on the tank the pump (centrifugal) can work, but as soon as the water level goes down and we start to pump the fluid it flash on the pump suction line.
RE: Pumping High Vapor Pressure Hydrocarbon Condensated
Failing that, if the liquid level can't be raised to give you at least 3' NPSHA, you may need to build some sort of underground well to locate a pump low enough to produce the suction head you need. You may also want to look at a very slow hydraulic diaphragm pump, I've used them with good results in service similiar to yours (drawing liquids out of hydrocarbon condensate knockouts on natural gas compressor battery inlets), though I had about 3' - 4' of NPSHA to work with in most cases.
RE: Pumping High Vapor Pressure Hydrocarbon Condensated
That's right, maybe I have to give them first more NPSH and try again with WILDEN, MRoy, Boc Edwards/Hick Hargreaves, etc. Which brand has you used the most?
Thank you
RE: Pumping High Vapor Pressure Hydrocarbon Condensated
On the centrifugal end, I've also used Dickow Pumpen and Sihi and pumps in low NPSH, low flow service, they have models with NPSHR down as low as 0.5 meters, which is still more than you're looking at right now. The trick there is their designs normally work of very tight clearance, so they don't work well in a service with any kind of solid contaminants.
RE: Pumping High Vapor Pressure Hydrocarbon Condensated
You could also look at raising the LLL. Another foot may make all the difference.
Canned suction centrifugal may not be an option given your flow rate is so low.
Another option might be to look at a low speed progressive cavity pump. Something by Moyno.
Tim