Impeller pump v diaphragm pump

[Hugh Foulis]

My shower discharge pump has gone u/s. The present model (Jabsco) has an impeller but exploring the options, similar capacity pumps are available with diaphragm rather than impeller. My view is that a diaphragm will cope better with small amounts of trash that an impeller will not and I am minded to replace on that basis.

Can anyone see a major flaw in this thinking?

HF

 

[VicS]

My shower pump discharge pump has gone u/s. The present model (Jabsco) has an impeller but exploring the options, similar capacity pumps are available with diaphragm rather than impeller. My view is that a diaphragm will cope better with small amounts of trash that an impeller will not and I am minded to replace on that basis.

Can anyone see a major flaw in this thinking?

HF

I think you will find that the little valves in a diaphragm pump will be intolerant of small amounts of trash. A filter in the suction will be essential and that will need regular cleaning.

I guess your present pump is a flexible vane pump ??

The most tolerant of debris is probably a simple (centrifugal ) impeller pump but that may not be practical solution as it will need a flooded suction.

 

[sailorman]

I think you will find that the little valves in a diaphragm pump will be intolerant of small amounts of trash. A filter in the suction will be essential and that will need regular cleaning.

i have has a PAR diaphragm bilge pump with strainer on an auto switch for the past 20 yrs with out problem. i have had to replace 2 duff switches in that time

 

[pampas]

+1 Iused one for deck wash system didnt like salt deposits even with filter, so went back to the old pump.

 

[Trundlebug]

Aren't holding tank waste pumps usually diaphragm pumps?
They seem to be designed to cope with "impurities"...

 

[prv]

I would always prefer a diaphragm pump for a shower drain. As Trundlebug says, holding tank pumps are usually diaphragms, as are almost all manual bilge pumps and the famously un-blockable Lavac.

The main "impurity" in shower water is hair, which shouldn't be too much problem for the tricuspid valves on a modern diaphragm pump but wraps itself tightly around the spinning parts of a centrifugal impeller pump.

The electric diaphragm pump I used as an auto bilge pump on Kindred Spirit was sold by Whale specifically for shower sump use. All the charter boats I've used which had showers, have had diaphragm pumps (you can tell by the rhythmic sound).

Pete