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All Springer/NP/PCP Air Gun Discussion General > "Bob and Lloyds Workshop"

Regulated Disco Valve

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rsterne:
Last year I made a regulator that attaches directly to a Disco valve.... I was working on different ways to produce a non-PAL PCP (ie under 500 fps).... It did the job by using a shortened 2240 valve spring.... Here's what it looks like....



It replaces the front end of the valve, and is long enough to cover the roll-stamped area on a 22XX tube.... I used the piston and spring from a Ninja regulator, so the parts are easy to obtain, in fact I just bought a Ninja rebuild kit to get them.... The back half of the valve, including the poppet and spring, are stock....



I installed it into a 2260 tube for testing.... I found the velocities more consistent with a lightened hammer (I went all the way to 30 gr. - 50% of stock).... Here is the shot string....



It appears that the regulator setpoint with just the spring (no shims) is about 650 psi.... I was quite pleased with the flatness of the shot string, 55 shots averaging 492 fps with 14.3 gr. JSB Express pellets, and the efficiency worked out to 1.21 FPE/CI.... I also tried it with a stack of Belleville washers (disc springs), and with a setpoint of about 1350 psi it gave 10 shots averaging 773 fps (19 FPE) with an efficiency of 1.13 FPE/CI.... The limited number of shots at higher power is because of the 2000 psi fill limit.... It only left 650 psi available, which is only 168 CI (at 1 bar) with a 2260 tube.... You could double that shot count by using a Disco tube.... but in reality there is little point.... Regulators are at their best when the setpoint is low enough to utilize a much wider range of pressure.... Having said that, shimming the coil spring a bit and bringind the setpoint up to about 1000 psi should give a good shot count and velocities in the high 600s.... Adjusted the way it is would produce a non-PAL Disco with over 100 shots per fill....

Bob

RatRacer:
Good and interesting stuff Bob!  Whens production start? :D

rsterne:
Strictly a one-of.... Wayyyyyyyyyy too much work to make without a CNC lathe in production quantities, IMO....

Bob

grumpy:
Man you got some serious skills. If the FPS was say 6-700 fps I would take several.

Dave

rsterne:
Velocities in the high 600s can be attained by pressures in the 1000 psi range.... maybe even low 700s with 14.3 gr. pellets.... Shot count would be the question, I'm guessing 50ish?.... It's NOT rocket science, all it takes is for someone to tool up and make the housing.... buy the Ninja regulator rebuild kits, and assemble them....

Bob

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