Creepy reg- cured but struggling to get over 80bar

[Squinty]

So I have aan E-bay reg that came fitted to my mk1 .20, performance was poor and I retrofitted fast-flow.
The reg has been my spare for tinkering, sets up ok but creeps after a month or in the case of FAC just fails and drops full pressure.

I refaced the core nose, it still crept so I replaced the delrin with PEEK.
TBH i think that the core seat should of had a flat bottom? And having a square base the delrin was slowly compressing into the small void. Hard to prove once it was drilled out.

I made the PEEK nose with a tapered base to remove the void athough with hindthought should  have squared off the bottom in the core.

Now the reset is crisp and has held constant at 1200psi for a  a week.

It was last on my 177, set at 95/1375psi with 0.5mm end-float.
Same washers, same float I'm struggling to get to pressure again.

Before I start pulling it apart again.. could it be shutting off too soon because there's no longer any compression in the nose?

Probably answering my own questions - I need to increase end float?

[KevG]

there should be no compression in the nose sealing face.,if the seal compresses into the core nose it can cause a slow idle reg.dont like using peek my self .always use white delrin after alot of testing and trials.travel of the core is not that realy important as long as its got slight travel and no more than 1mm.if it as the locking oring on the brass threaded collar these can cause set pressure problems as the orings flexibility comes into play.ok when in good condition but can go over hard or to soft.thats why I dont use them when doing new regs.
KevG

[KevG]

have you also checked that the brass collar is not moving when your adjusting reg.
KevG

[Squinty]

Cheers Kev.
All new o-rings, i shall strip it down again and check travel but I made a full turn for about 20psi,

Sorry its a short core so less compression/movement ...I would have hoped for more.

The collar isn't moving, marked it up for reference.

There are a few  that have upgraded to peek core noses- mostly FAC from what I've read.
Kill or cure, its harder than Delrin which could have its own issues but a few bits that I've made with it have been good.

BTW those BSA valves you converted for me are still going strong with the PEEK pips, barely a mark on the tips and no sign of mushrooming on the sealing face

[KevG]

you don't think the peek as pushed back into the first flow hole into the core do you with it being tapperd .glad the valves are still holding up m8
KevG

[Squinty]

Ahhh...had to think for a moment......got ya.

No I didn't taper the nose to a sharp point, 112-120 degrees, I heated up a bit of delrin to check the seat angle.

I'll double check tho.

They've been great, rock solid ( jinx ) no air loss or change of contact.

[Squinty]

you don't think the peek as pushed back into the first flow hole into the core do you with it being tapperd .glad the valves are still holding up m8
KevG

no significant movement of the nose, endfloat has settled at 0.59. I can live with that.
Back in the tester and still stuck around at 1200psi.

[KevG]

have you tryed doubling up the bellevilles or adding an extra one.
KevG

[Squinty]

I have considered doubling up, these if I remember correctly were good for  110-150 but quite slack below that.
Who knows may be OK with the new nose.

[Dave74]

If stack is slack reducing pressure need another washer or 2, short core reg end float will be preset and don't have push pin disc over tightened