Polyurethane o rings?

[muzzie]

Hi
I'm having trouble finding 19x2mm polyurethane o rings for my Aeron Brno B96.... Any ideas please...the normal ones seem to blow, I'm not the only one apparently , must be a fault?

Thanks

[ChrisC]

Hi
I'm having trouble finding 19x2mm polyurethane o rings for my Aeron Brno B96.... Any ideas please...the normal ones seem to blow, I'm not the only one apparently , must be a fault?

Thanks

After a quick search ...these mention poly
http://www.oringslimited.co.uk/products/o-rings/

I use a company cally Polymax so maybe worth a try?

Does it have to be Poly?.......maybe Nitrile or Viton might be better.

Let me know mate as i've just checked and can get some Nitrile shore 70 19x2, EPDM or EPDM 70 ShA Peroxide Cured FDA (is the 19 the ID or the OD?)

[muzzie]

After a quick search ...these mention poly
http://www.oringslimited.co.uk/products/o-rings/

I use a company cally Polymax so maybe worth a try?

Does it have to be Poly?.......maybe Nitrile or Viton might be better.

Let me know mate as i've just checked and can get some Nitrile shore 70 19x2, EPDM or EPDM 70 ShA Peroxide Cured FDA (is the 19 the ID or the OD?)

Cheers Chris
19x15 outside/inside, poly as some one told me they are best way to go??? I bow to your superior knowledge ,what do you think.
The problem is the o ring that seals the co2 bulb in the grip, they supply 2piercers, I suppose to let the first to comeback to "room temp"
Also ,when storing a PCP you keep it filled, how are you supposed to store a co2 pistol, full or empty?
Cheers

[ChrisC]

Cheers Chris
19x15 outside/inside, poly as some one told me they are best way to go??? I bow to your superior knowledge ,what do you think.
The problem is the o ring that seals the co2 bulb in the grip, they supply 2piercers, I suppose to let the first to comeback to "room temp"
Also ,when storing a PCP you keep it filled, how are you supposed to store a co2 pistol, full or empty?
Cheers

I can get you some mate and pop in the post. If they don't work then no probs but if they do i can always get you some more.

I would think storing a Co2 pistol should be done empty but that means you have to shoot the bulb empty after each use.

[deejayuu]

As ChrisC says. Manual for Umarex Beretta FS 92 says store empty to relieve pressure on seals etc.
I just spill mine if part full and not shooting. Hope that helps.

[muzzie]

I just spill mine if part full and not shooting. Hope that helps.

Spill ...do you mean just release the gas...is this a Tech word?

[muzzie]

I can get you some mate and pop in the post. If they don't work then no probs but if they do i can always get you some more.

I would think storing a Co2 pistol should be done empty but that means you have to shoot the bulb empty after each use.

Thanks for that Chris , let me know what I owe you, which one would you recommend, I'll pm you my address later.
Cheers

[air-tech]

Just for everyone's benefit, there is a vendor on ebay goes by the name of Bohemia seal, and they supply awkward size o-rings even in very low qtys down to singles, have bought from them on a couple of occasions when stuck for a seal.

[ChrisC]

Thanks for that Chris , let me know what I owe you, which one would you recommend, I'll pm you my address later.
Cheers

Got your PM Neill, no charge mate.

[Benelli B76]

As ChrisC says. Manual for Umarex Beretta FS 92 says store empty to relieve pressure on seals etc.
I just spill mine if part full and not shooting. Hope that helps.

Any pistol that seals the CO2 capsule on the end should be emptied after a shooting session to relieve pressure on the seal from the capsule contact, as you say on pistols like the Beretta. Other pistols that seal the gas differently on the seals such as the Aeron, Drulov and others are better left pressurised with gas. Regarding comments on other posts regarding polyurethane, it is a far better material than Nitrile or Viton for sealing longevity.

Baz

[deejayuu]

Spill ...do you mean just release the gas...is this a Tech word?

Spill as in let it escape

[muzzie]

Any pistol that seals the CO2 capsule on the end should be emptied after a shooting session to relieve pressure on the seal from the capsule contact, as you say on pistols like the Beretta. Other pistols that seal the gas differently on the seals such as the Aeron, Drulov and others are better left pressurised with gas. Regarding comments on other posts regarding polyurethane, it is a far better material than Nitrile or Viton for sealing longevity.

Baz

Thanks , so IYHO,you think poly is a better way to go, I'm getting a little confused, everyone seems to have different opinions.
Cheers

[Aimstraight]

I would be interested to know how you get on with the seals from ChrisC.

I have a Tau 7 which also has an issue with the o-ring in the piercing cap (similar design to Aeron and Drulov). Fitted new o-ring direct from Sureshot, cocked the pistol to take any pressure off the hammer, but yet again on first shot, all CO2 blows out of the seal at the base of the grip. The seal is not visibly damaged, but it distorts in one location (presumably where the CO2 leaks out), then recovers later on.

It seems that the cap might be piercing the CO2 bulb before the cap is fully screwed in (before o-ring is fully compressed). Then maybe the first shot causes a pulse/change in pressure within the C02 chamber in the grip, which causes the pressure on the seal to fluctuate, leading to a distortion/deformation of the o-ring and loss of gas? This is not a case of a cold piercing cap/seal, it even happens on first use, and has happened several times. The design consisting of an o-ring sliding inside the tapered walls of the chamber (as opposed to sealing the end of the chamber) seems to be very susceptible to tolerances on the o-rings and chamber.

[muzzie]

I would be interested to know how you get on with the seals from ChrisC.

I have a Tau 7 which also has an issue with the o-ring in the piercing cap (similar design to Aeron and Drulov). Fitted new o-ring direct from Sureshot, cocked the pistol to take any pressure off the hammer, but yet again on first shot, all CO2 blows out of the seal at the base of the grip. The seal is not visibly damaged, but it distorts in one location (presumably where the CO2 leaks out), then recovers later on.

It seems that the cap might be piercing the CO2 bulb before the cap is fully screwed in (before o-ring is fully compressed). Then maybe the first shot causes a pulse/change in pressure within the C02 chamber in the grip, which causes the pressure on the seal to fluctuate, leading to a distortion/deformation of the o-ring and loss of gas? This is not a case of a cold piercing cap/seal, it even happens on first use, and has happened several times. The design consisting of an o-ring sliding inside the tapered walls of the chamber (as opposed to sealing the end of the chamber) seems to be very susceptible to tolerances on the o-rings and chamber.

Hi,Chris said that he won't be able to post for a couple of weeks, what o rings are you using?
Have you spoken to the manufacturers, what do they say...hopefully someone one here will be able to help...they normally do.
Cheers

[Aimstraight]

Hi,Chris said that he won't be able to post for a couple of weeks, what o rings are you using?
Have you spoken to the manufacturers, what do they say...hopefully someone one here will be able to help...they normally do.
Cheers

I fitted the standard replacement o-ring from a Tau 7 seal kit from Sureshot. I have checked that there are no burrs on the threads of the piercing cap. The inside of the gas chamber is in very good condition. Seems that some o-rings do not provide a satisfactory interference fit. I also bought a second 12gm piercing cap (the spare that came with the pistol was for an 8gm bulb), so will give that a try to see if there is any improvement.