Parker Solenoid Valve
The solenoid valve used in the Rancilio Silvia and the Gaggia Classic, is quite an expensive item to replace. I have put together a seal kit for the plunger (aka nucleus or armature) as the estimated service life is quoted as one million cycles per valve. The seals are normally a green FKM material (known as Viton by DuPont) or synthetic ruby (not in Gaggias or any Silvia I have seen). I am not sure why FKM was chosen but possibly for its strength to abrasion rather than steam resistance (standard FKM is not recommended for steam service or food applications). I have chosen 25% glass filled PTFE as a replacement for the following reasons
Extremely good chemical resistance against virtually all media including steam
Wide temperature range (up to +250ºC)
Glass reinforcement provides improved wear resistance in comparison to virgin PTFE
Improved dimensional stability
Improved creep resistance and food safe
Also testing FDA approved peroxide cured EPDM.
Now offering a kit for £4.99 plus postage. This will include the 2 plunger seals, the plunger tube to flange seal and the flange manifold seals. This kit will fit the Parker Hannafin VE-128 (previously PM-128 I believe). Fitting the plunger seals can be a bit fiddly till you get the hang of it and if you want you can send the valve or just the plunger and I will fit FOC. Do de-scale the flange and plunger tube in citric acid and inspect the valve seats for any visible wear before reassembly.