TargetTalk

How do you adjust the spring pile in the LP200 regulator to 70-80 bar ?
I have to re-build a LP200 regulator with new after market Breville washers,
How do you setup, measure and test the pressure regulator ?
New regulators or spring washers are no longer available from Walther,
only O rings.
Adjustment is via the top poppet valve spring and the lower spring pile tension.

Some manufacturers (like Steyr) actually have a pressure gauge that the regulator assembly can be attached to. If Walther no longer supports the pistol with parts, it's unlikely they would sell you a gauge (if they had one).

As long as you understand how the orientation of the Belleville washers in the stack affects the force, you may be able to zero in on the right arrangement by experimenting until you get a nominal velocity out of the pistol. That assumes the velocity adjust screw hasn't been messed with. I imagine taking the pistol apart that far & reassembling it will be a royal pain.

You don't say what's wrong with the original washers. Some manufacturers use plain steel washers, which can corrode if you get a cylinder fill with moisture in it. Even if they are lightly corroded, they can probably be polished to work pretty close to normal. If you know the orientation of the washers in the original stack, one option would be to restack them, and place them on top of a stack of the new washers. Compress the double stack, and arrange the new springs until the deflections match. That will at least get you in the ball park.

As long as the dimensions, especially the thickness & initial "dish" of the washers, is the same, they should behave very similarly. You could start by just duplicating the original stacking. (I wouldn't trust the picture, it could easily be for illustration purposes only).

Good luck!

Thanks, it looks like being a trial and error job.
Failed O ring on the poppet valve, allowing the full tank pressure into the
pre charge chamber and flatting the origional washers left under load
for a long time and have lost most of their tension.

Ouch! That definitely limits your options. Short of prying info out of Walther on the washer specs, trial & error may be all you can do.

One other possibility is to see if they use the same part number washers in a different pistol The Belleville washer stack is pretty much an industry standard for these things. If they have the parts working well in one pistol design, they'd be silly to change parts for no good reason (although I've seen it done). However, if they used them in a newer pistol, I would think they could still supply them as repair parts.

You know....MOST of the time, use of a silicone based oil "blown thru" the gun will lobe the regulator washer stack and get them moving relative to each other again. I would certainly to that before I panic too much....... Its easy

I am not sure it is super critical. I have an older LP 10 that was delivered ()()()(), and a new Evo.that was delivered (())(()) they both can be adjusted to shoot right at 500 fps with the striker spring. While I realize that the springs play a part in the regulation, I think the bigger factor is the two piston sizes. Once the bigger, low pressure, side has enough pressure, it closes the inlet to the high pressure. You can have a higher plenum pressure with a lower dwell time of the striker, or a lower plenum pressure with a higher dwell time. As long as I got the velocity I needed, I would opt for a lower pressure, like 60 bar. That would get you more shots per cylinder prior to the plenum pressure equilizing with cylinder pressure. Obviously once that happens your velocity continues to drop.

OK, at the moment a full 200 bar tank, the pistol is only giving about 85m/s.
Reduce the tank to 140 bar and I get the desired 145-155 m/s.
Reduce further to 100 bar and the shots are up to 188-190 m/s.
The regulator is not doing its job with the old springs.
I may havee to make some sort of adaptor to measure the pre charge chamber pressure.

You might want to check with this guy:

https://www.ebay.com/itm/113193024516

If the regulator comes off as a unit, there are various gadgets to test them. Thsi site has soem possibly useful info:

https://airgunaccuracy.wordpress.com/wa ... egulators/

Good luck!

David M wrote: ↑Fri Jun 17, 2022 3:50 pm OK, at the moment a full 200 bar tank, the pistol is only giving about 85m/s.
Reduce the tank to 140 bar and I get the desired 145-155 m/s.
Reduce further to 100 bar and the shots are up to 188-190 m/s.
The regulator is not doing its job with the old springs.
I may havee to make some sort of adaptor to measure the pre charge chamber pressure.

It is odd that it is functioning inverse to pressure cylinder pressure.

Is there any possibility that the high pressure(small) side of the piston has a bad o-ring? That could cause the imbalance of the piston, so that the low pressure side (big) closes the inlet valve prematurely.