Couple questions about HPA for QB...

Couple questions about HPA for QB...

Joined: January 18th, 2010, 6:04 am

July 24th, 2012, 1:30 pm #1

Thinking of getting QB and going HPA for the winter.
But two questions; The HPA bottle has regulator and they are known to fail at some point, right? If yes, when/if they do, I assume the whole 3000psi will go right into QB main tube,right? Is there any danger that tube to fail as well in that case? Is the tube think enough to hold 3K of air? Or do regs rarely fail? How do you guys go about that?
Second question; when you screw the HPA bottle into the gun, I am sure that the fill nipple and gauge are not always timed right-end up at the right position. So, do you shim the bottle? If yes, do you shim it at the gas block or where regulator meets the bottle?
Thank you very much.
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Joined: January 14th, 2011, 9:42 pm

July 24th, 2012, 2:09 pm #2

... I always make sure there is a blowout disc downline from the regulator so the QB tube would never see the full 3000PSI. My bottles are all regulated to 1100PSI so I put a 1500PSI blowout disc in.

As for where the gage and fill end up, you can shim most of the newer regulator/valves but I have never had to. There are 3 ports (fill, blowout and gage) in my Ninja bottles so I have swapped those 3 things around to make life easier.
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Joined: January 18th, 2010, 6:04 am

July 24th, 2012, 2:38 pm #3

...1.5K burst disks available to buy at paintball shops? I thought only 3K ones are sold?
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Joined: January 9th, 2005, 1:46 am

July 24th, 2012, 6:47 pm #4

I'd just like to reinforce the point knt made about never allowing 3,000psi into the factory main tube. They are definitely NOT designed or made to withstand such pressure and the consequences could be very dangerous. Only CO2-level pressures should ever reach the main tube (~900psi).

That obviously makes the importance of the burst disk that much greater!

Stephen Archer
Archer Airguns Inc.
Online stores http://www.archerairguns.com
http://www.archerpelletguns.com
Videos http://www.youtube.com/ArcherAirguns
Blog http://www.archerairguns.info
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Joined: January 18th, 2010, 6:04 am

July 24th, 2012, 9:35 pm #5

What is the distance between the gas block and the end of the barrel/muzzle of the gun?
Thank you
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Joined: January 9th, 2005, 1:46 am

July 24th, 2012, 10:20 pm #6

Anatoli,

The distance from the front (external) face of the gas block to the end of the barrel is approximately 16 5/8 inches for the QB79.

Stephen Archer
Archer Airguns Inc.
Online stores http://www.archerairguns.com
http://www.archerpelletguns.com
Videos http://www.youtube.com/ArcherAirguns
Blog http://www.archerairguns.info
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Joined: January 18th, 2010, 6:04 am

July 25th, 2012, 12:13 am #7

Thank you Steve very much. NT
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Joined: November 17th, 2006, 3:51 am

July 25th, 2012, 1:57 am #8

Thinking of getting QB and going HPA for the winter.
But two questions; The HPA bottle has regulator and they are known to fail at some point, right? If yes, when/if they do, I assume the whole 3000psi will go right into QB main tube,right? Is there any danger that tube to fail as well in that case? Is the tube think enough to hold 3K of air? Or do regs rarely fail? How do you guys go about that?
Second question; when you screw the HPA bottle into the gun, I am sure that the fill nipple and gauge are not always timed right-end up at the right position. So, do you shim the bottle? If yes, do you shim it at the gas block or where regulator meets the bottle?
Thank you very much.
The regulator has burst disk safety (a part made to blow open past a certain pressure)...the output side should be a 1.8K disk. That would still let 1.8K of pressure inside the gun. I'll even go farther by using an on/off that has both a gauge (to read the output) and a second 1.8K burst disk.

IF you did manage to dump 3K o air into a QB79 tube, would have one of three things are MOST LIKELY to happen. (1). Could shoot the gas block/tank off like an air powered rocket. (2) Blow the o-ring seals and just leak (3) hold the pressure but be valve locked (too much pressure for the striker to open the valve and shoot). Of the three, only the first would be dangerous.

COULD it blow the tube up? Possiblebut the two screws holding the block on and the o-rings are the weak links, and theyd go first.

Have I had it happen? No. Have had a regulator fail (a brand other than the ones now in use) but it just blew the burst disk. Have had co2 tanks also blow their burst disk, so its not a trait of HPA tanks alone.

Here are 4 QBs running on HPA
[/IMG]

Others go much higher, but I get all I want with 850PSI output.

A look at the brass gauged on/off. Cant see the 1.8K burst disk as it is opposite the gauge
[/IMG]

Right..the tanks can line up any way. A shim between the HPA bottle and the tank block (a thin washer works fine, so long as it doesn't cover up the gas inlet hole of the block) can get the nipple or gauge out of the way for barrel installing (and you can get all OCD about it and get the nipple and gauge to end up where ever you think is "perfect" by using different thicknesses of shim). Other people just use an 0-ring..will compress as you screw the tank on.. once it is pressurized by 850PSI output, it won't rotate.
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Joined: January 18th, 2010, 6:04 am

July 25th, 2012, 3:08 am #9

what brand regulators do you use?
Thankyou
Last edited by tolikstf on July 25th, 2012, 3:10 am, edited 1 time in total.
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Joined: November 17th, 2006, 3:51 am

July 25th, 2012, 11:04 am #10

Most of the tanks run with a Ninja regulator. On/Off from Real Action Paintball (RAP4).
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