need a drum pump

[RobWard]

We need a pneumatic drum pump to pump methylene chloride to top up some tanks on machines.
We tried a couple but they couldn't suck the last few inches from the drum (I'd settle for 1" maximum left in the drum), or worse they siphoned when dispensing to a lower level (a container on the floor) which was "interesting" to watch as people struggled to stop the flow.
We don't need a fast flow rate (had to fit a regulator to the pump to slow it down).
(The diaphragm pump we tried pulsed too violently, causing lots of splashing in the tanks).
So, does anyone know where we should go to get a pump to do what we need (or indeed what type I should look for)
PS We're in the UK.

 

[DiaphragmPumps]

Hi, a couple of things, a) methylene chloride is compatable with only a few elastomers eg Viton & Teflon of the 2 Viton (being softer) will seal in the valves better and prime more easily. b) To ensure emptying the vessel a footvalve would be ideal, altho with the viton seals you may not need it. c) A flow wasn't mentioned, but it is common to use 1/2" ported pumps for drum emptying, using a larger unit will help with the prime as change over is reduced due to the larger capacity, and it is the change over which causes problems with prime. d) as regards syphoning, the simplest way is to introduce a spring loaded check valve on the discharge line. this would require the pump to be running to force it open and deliver the product, but the spring pressure would hold it closed when the pump is inactive. e) A regulator is not ideal to control the pump as the flow rate will alter against different pressures. Use a needle valve on the air line to regulate flow. I hope this answers your queries, but please contact me if you require more information

http://www.diaphragmpumps.co.uk

 

[fredb]

Hi,

A double diagphram pump such as the Wilden is probably your best bet. To eliminate the pulsations on the discharge, consider installing a small tank to serve as a reservoir. To drain to the bottom. Fabricate a suction fitting that will suck from a continuous slot along the sides with the bottom closed. The slot area to be the same as your hose i.d.