Originally Posted by F470
It was the FC-470 Valve Diaphragm in particular that seem to have softened/melted. Is the Valve Diaphragm silicone? It appears to be regular rubber. I will try silicone grease. Do you sell seals and gaskets for the FC-470?
The inlet valves have three primary rubber components:
The lid gasket.
The sealing o-ring.
The one-way valve.
All three of these components are neoprene (chloroprene) rubber. They should be coated with a light coating of Dow Corning 111 or similar silicone grease. Silicone grease should be available at your local Dive Shop.
Lid Gasket : PN Z2213
One Way Valve : PN Z2195
The sealing o-ring can be replaced by a Buna-N 70 duro o-ring, size 213. You can purchase this from your local o-ring supplier, such as Martin Fluid Power. Or, if you want to pay a 10,000% markup, it is PN 2212.
Also, disregard the "MCG 111"...That references a perfluoropolyether grease by Christolube for O2 clean systems. It is Dow Corning 111 you'd want if you want the brand name silicone grease.
Check your local recreational Zodiac dealer. They should have the Z2213 and Z2195 in stock.