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rsterne · Moderator

I have had several inquiries about how to adjust the pressure output on Ninja (and other) regulators.... AirGunEric at www.scopesandammo.com supplied me with a 2000 psi output Ninja regulator for experimental purposes and I took it apart and documented how it was assembled.... Then I removed some of the cup washers and shims and documented the effect on pressure as they were gradulally added back in....

First of all, it is necessary to explain what was inside the 2000 psi regulator.... When I pulled it apart, I discovered that there were two different thicknesses of shims and two different thicknesses of Belleville Washers (also known as Disc Springs).... The shims were in a stack in the bottom of the regulator housing.... In my regulator, there were two 0.005" shims and two 0.022" shims.... totalling 0.054" of shims.... My regulator was basically right at 2000 psi when checked with a gauge from a Hill pump which has 100 psi increments.... Cool

The disc springs which were on the stem of the piston consisted of a 0.022" thick disc spring on each end, and a total of ten 0.032" thick disc springs arranged in a "single stack" arrangement.... The total stack looked like this:

|| || ) ) ( ) ( ) ( ) ( ) ( (

I used a vertical line to denote a shim, and a bracket to denote a disc spring.... The thicker ones are shown in bold....

I removed all the shims and the two thinner disc springs, reassembled and tested the pressure, and it was only 400 psi.... I added back one of the thinner disc springs, and the pressure was then 800 psi.... I gradually added shims and recorded the pressures (red line on the graph).... I then removed the shims and replaced the second thin disc spring, at which point the pressure was 1100 psi.... I then gradually added shims and recorded the second (green) curve....

I have a regulator rebuild kit which I purchased from Eric, and it had two thin and two thick shims in it.... The thick shims were coloured red, and measured 0.020".... For the same of simplicity, I redrew the curves using calculated points 0.010" apart which are what is shown on the final graphs.... Please note that these pressures were taken with only one single regulator as a sample lot.... so your regulator may vary.... The thick Ninja shims I have vary between 0.019" and 0.022".... and I'm sure there are production variations in the disc springs.... but I would hope that if you used the total shim thickness from the graph you would be within about 100 psi.... or about one 0.005" shim.... Extrapolating the upper graph would indicate that a total of 0.070" of shims would bring the pressure to about 2500 psi.... but this has NOT been tested and the regulator may be getting close to "spring bound".... If that occurs, it would run wide open and not regulate at all.... the output pressure would be the tank pressure....

There are some safety precautions I must mention if you are contemplating adjusting your regulator presssure:

1. MAKE SURE THE TANK IS EMPTY BEFORE YOU DISASSEMBLE THE REGULATOR.... If you remove the bonnet (upper part) of the regulator with pressure in the tank it will blow off under pressure.... You could be injured or killed....

2. Check the pressure of the downstream (low pressure) burst disc.... If it is only a 1.8K rating and you set the regulator pressure over about 1500 psi you may blow the disc.... The same thing applies if the regulator sticks in the open position.... If you are trying for a pressure over 1600 psi you must fit a 3K burst disc (but not higher)....

3. I am NOT recommending that you try and alter the regulator pressure.... I am simply supplying the information I collected on MY regulator for those that are interested in that information.... HPA is dangerous, and if you don't know what you are doing, then DON'T....

4. If you have a different brand of regulator, this information will likely not be valid....

I purchased a 48 cu.in. tank with a Ninja Regulator and I wished to uprate the output pressure so that I can fill my Disco with it in the field.... The original regulator was set to 850 psi, and used a coil spring and shims instead of disc springs.... I measured the dimensions of the regulator, at it appears to be identical to the higher pressure units that do have disc springs.... I have installed an identical set of disc springs and shims into that regulator as my 2000 psi unit and when I refill my SCUBA tank I will be checking the pressure and let you know how it worked.... I had to replace the burst disc with a 3K unit....

I hope you find this information useful.... Remember....

HPA IS DANGEROUS.... PROCEED AT YOUR OWN RISK.... A MISTAKE CAN BE FATAL....

Bob

rsterne · Moderator

WARNING: IF YOU ARE CONTEMPLATING WORKING ON A REGULATOR, DO NOT RELY ON THE ABOVE CHART.... IT IS ONLY A GUIDE.... YOU MUST TEST YOUR REGULATOR OUTPUT WITH A GAUGE....

OTHER POTENTIAL HPA PROBLEMS:

Crosman 22XX tubes were never designed to hold pressure.... QB78/79 tubes are apparently viewed by the manufacturer as safe for CO2 pressures with normal precautions.... ie never exceed 120*F (49*C) and don't overfill.... Similar dimensions of seamless, drawn over mandril, steel tubing are rated with a safe working pressure of 2000 psi for the Crosman size (0.875" OD x 0.065" wall) and 1700 psi for the QB size (22mm OD x 1.5mm = 0.057" wall).... this does NOT mean those are safe working pressures for the Crosman and QB tubes.... but it gives an indication of MAXIMUM pressures that should even be considered....

Crosman 22XX tubes have a safety warning "roll-stamped" into the tubing.... sometimes this is so deep you can actually see deformation on the inside of the tube.... This SERIOUSLY WEAKENS the tubing and this area should NEVER be subjected to pressure.... I would doubt the safety of some of the worst examples I have seen at even CO2 pressures.... Pressurization of these tubes should only be attempted if the valve is extended so that the seal (O-ring) is ahead of the roll-stamp....

Crosman 22XX valves are only located in the tube by a single 6-40 screw that can shear easily even under CO2 pressures.... the MINIMUM attachment acceptable for the valve is as per the Discovery.... three 8-32 screws with the heads tightened against the valve so that the loads are spread out.... having the heads in shear would be even better.... I am not familiar with the QB valve attachment method and it's suitability for pressure.... perhaps someone knowledgable could post that information in this thread....

The QB79 Tank Block is commonly used to allow a bulk CO2 tank or a regulated HPA tank to be attached to the main tube.... IMO, the attachment system for this block has a serious design flaw and the QB tank block should NEVER be used for HPA without modification.... The two screws used to mount it are soft, and are too close to the end of the tube.... There has been at least one recorded case of the holes starting to tear out and the screws shearing off because of a regulator failure which pressurized the tube to 2600 psi.... The tank block / regulator assembly blew off the end of the gun and went spinning across the floor.... fortunately, nobody was injured.... The screws should be replaced with at least Grade 5 screws (even for CO2 use) and in addition a shear pin (minimum 3/16") and/or two or three 8-32 screws with the heads in shear added to prevent the tank block from blowing off the end of the tube....

With all of the above things to consider, anyone contemplating an HPA conversion of either a Crosman 22XX tube or a QB 78/79 tube should insure that a 1.8K burst disc is fitted to limit the main tube pressures.... This effectively limits the regulator pressure to 1500-1600 psi to prevent the burst disc from blowing (they have a 200 psi tolerance, and the regulators are typically 100 psi tolerance).... If you use a CO2 tank (rated 1800 psi) and hand pump it that would be the equivalent....

NOTE: I AM NOT RECOMMENDING THAT ANYONE USE HPA ON ANY GUN NOT DESIGNED FOR IT.... YOU DO SO AT YOUR OWN RISK.... I AM NOT AN ENGINEER, AND DO NOT GUARANTEE THAT ANY OF THE ABOVE INFORMATION IS SAFE.... HPA IS DANGEROUS AND ANY ERROR OR FAILURE COULD RESULT IN INJURY OR DEATH !!!

Bob

sniper · Silver Status Member

what i would like to ad....

i run airless paint sprayers @ 3300psi .

that will shoot pudding thick paint into your skin and veins and KILL YOU!
what this means, there is no air.. but liquid under piston driven pressure alone. psi is psi. (consider the lead in front of it).

that being said. HPA will F$%K your day up quick...
one is air. one is not. both "high pressure".
just lookin' out for bob. Wink

my $.02.

and man.. you wanna feel pistol "recoil". lemme hook up my rig with some exterior paint on a "619" tip @ 2500psi. do that for a year and a 1911 is no problem. Mr. Green

i have mild arthritis in my trigger finger. Rolling Eyes

more so work than play. Rolling Eyes

trust bob. HPA is not for fun.....

portland_jon · New Member

Bob

Thanks for your wonderful work above, I will be putting it to good use when I get my ANS reg working. I have lost the pin valve from it, that's the pin that opens the reg when it is screwed onto the gun, and I am trying to find another one or the sizes so I can make one. I don't suppose you or any other members have one that they could measure or an old reg that I could aquire?

I know you have the Ninja reg but I'm sure that the pin will be a similar size, I just need something to work off.

Thanks

Jon

rsterne · Moderator

I opened up an 1800 psi Ninja Regulator today and found that instead of using thinner cup washers on both ends, they used the thicker (0.032") ones (as used for the middle portion of the stack).... In addition, there were some shims, in this arrangement:

| | ) ) ( ) ( ) ( ) ( ) ( (

The total shim pack was 0.030" and the tested pressure was just under 1800 psi.... I tried various shim thicknesses and updated the graph, adding another line using the belleville washer pack as above.... The results (including the previous) are below:

Please note that these tests were performed on only a single regulator and manufacturing tolerances will have an effect on the exact pressure reached with any given shim pack.... All the same warnings and cautions mentioned in the first post still apply....

I hope you find this information useful.... Remember....

HPA IS DANGEROUS.... PROCEED AT YOUR OWN RISK.... A MISTAKE CAN BE FATAL....

Bob

rsterne · Moderator

I have edited the above graph to include the spring style Ninja regulators....

Bob

AirGunEric · Site Admin

rsterne · Moderator

The "base" setup is without any flat shims, just the 12 Bellevilles, which could be all thick (0.032"), 11 thick and one thin (0.022"), or 10 thick and two thin.... The end washers are in parallel to the last thick ones (ie nested within them).... As such, the end "pair" deflect very little, with the extra washers within them acting partly as a shim and partly to increase the spring rate of the last pair.... Basically the 8 center Bellevilles (in series, ie cups opposing) do most of the work....

My guess is that if the factory 1800 psi setup had two 0.032" shims in addition to the 12 Bellevilles, then the Bellevilles were not 0.032" thick, or if they were, they were a lower spring rate than the ones I tested.... My 1800 psi regulator had 12 0.032" Bellevilles plus a total of 0.030" of flat shims....

Bob

AirGunEric · Site Admin

Interesting video: https://www.youtube.com/watch?v=h91iIVOJ7JU