Too high IP in a piston first stage

[emoreira]

Hi, just a question.
I've got a fairly common non balanced piston first stage. I've cleaned thoroughly, changed o-rings, lubed with christolube, reassembled and tested with an IP gauge.
The IP showed 12 bar, fixed.
It has only the two thin plastic washers in each end of the main spring. One against the body and the other against the piston.
The main seat was ok, with a minimal mark.
Which is the following step to adjust the IP to 10 bar ?
Adding washers should rise the IP even further.

 

[lexvil]

How much in dumb American is 12 bar?

 

[Gone for diving]

Don't know about all.

But some you can't change unless the spring is made shorter... be very careful,
doesn't take my grinding to change IP alot....

This is my way of doing it... not sure what the official way is..... maybe new spring..

 

[grf88]

Approximately 402 inches of water.

 

[Gone for diving]

14.5 psi per bar, almost 1 atm

 

[lexvil]

I would start with removing both shims.

 

[rsingler]

Remove one or both shims.
Or as noted,
Carefully place the spring end against a belt sander and take off 10/1000ths of an inch of metal, a little bit at a time. Don't let the steel scorch or blue, or the temper will change.
Easy, peasy. Your IP drops.
Another way would be to take a TINY disc of paper, and put it behind the HP seat, raising it in its carrier 10/1000ths of an inch.

 

[BoltSnap]

How much in dumb American is 12 bar?

12 bar = 174.05 PSI

1 bar = 14.50 PSI

1 Atm = 14.70 PSI

 

[Open Ocean Diver]

How much in dumb American is 12 bar?

174 Google search

 

[Open Ocean Diver]

Wait a minute if he reused the seat, couldn't there be a leak now in the seat?