NoTies is right: the membrane housing is proprietary and you are probably going to have to contact Katadyn
to get one. If and when you do that, I suggest you first contact Chris V. at:
chris.v <at> katadyn <dot> come
and see if he will work
you a deal. He may have some used ones lying around in their facility in Minneapolis.Tell him Gary from S/V Ishi referred you.
However, if you only have the pump
, you will still need to obtain/purchase the two membranes that go into the housing, as well as the high-pressure hoses, none of which are cheap
Finally, it would be a shame to buy all those expensive items, only to discover that there was something defective in the pump or motor. Again, your best solution might be to contact Chris, tell him your situation, and see what they would charge to have you return your pump/motor assembly to the factory and have them do a complete rebuild
. That would very likely cost considerably less than buying
a new unit ($3000+). You might be happier in the end.