P38A EAS Solenoid Valve Sizes

Been looking at several valve blocks today prior to refurb, and wondering about the solenoid valve sizes. The "PaulP38" info states there are 3 sizes - small one for diaphragm, medium for corner valves, and larger size for Inlet & Exhaust.

In my case, ignoring the diaphragm solenoid, I found 3 sizes for the other valves: (i.e. 4 sizes in total)

• Corner valves in all cases are 2.0mm
• 1st block has 4.0 for both Inlet & Exhaust
• 2nd block has 2.5 Inlet & 4.0 Exhaust

Q1) Wondering if a previous owner has been mixing valves around, or if the 2.5mm & 4.0 solenoids are from different years ?

Q2) Should 4.0 be used for Inlet to allow pump to pressurise the tank quicker ?

This is Inlet & Exhaust 1st valve block:



This is Inlet (2.5) & Exhaust (4.0) on 2nd block.

seems like no one knows?

Dopey said:

seems like no one knows?

Click to expand...

Where's your dad when he's needed?!

Hes playing mummy & daddy.... dirty boy

Is there any physical difference between them?

Mark, the difference is in the opening size where the air flows. It makes sense to me to have a 4.0 Inlet feeding two x 2.0 corner valves, but I'm wondering why some valve blocks have 2.5mm Inlet valves?

Another problem is worn rubber on the plungers. I cannot seem to find if these can be replaced ?

Got it, maybe as you say different years of manufacture brought about small changes.
As for the rubber ends, I polished or rubbed down a couple on my own block using a cordless drill and some really fine Emery cloth. Holding the cordless as squarely as possible and very carefully...

pwood999 said:

Mark, the difference is in the opening size where the air flows. It makes sense to me to have a 4.0 Inlet feeding two x 2.0 corner valves, but I'm wondering why some valve blocks have 2.5mm Inlet valves?

Another problem is worn rubber on the plungers. I cannot seem to find if these can be replaced ?

Click to expand...

Solenoid plunger seals can be refaced and if needed removed and refitted with suitable thickness washers to space them out to correct protrusion. Or replaced altogether using suitable sized Nitrile o'ring rubber stock.