We have recently been contacted by Brian Stephens of South Wales who is restoring a Hatfield Merryweather trailer pump. He tells me it has a Meadows engine in it, and judging by the photos, he is well on the way with a very comprehensive restoration.
Anyway, the reason for him contacting me was to ask advice on how to operate the thing. Now all our pumps are centrifugal, but three-cylinder positive pumps are quite a different beast if you don’t know what you are doing, with the capability of bursting a hose or blowing the cover off a cylinder if the water flow is abruptly stopped. However, it shouldn’t happen if there is a pressure relief bypass valve. Also, I gather the unit has a clutch, which means you can start the engine with the pump disengaged.
So if any of you have any manuals for the Hatfield pump, or any experience with positive pumps, I am sure Brain would love to hear from you. Also, do you know what the control is in the top centre between the top two cylinders? Contact firstname.lastname@example.org uk and we will pass it on to Brian.
You can see some of the Merryweather products here.