Atomic Service Question

[fnfalman]

The manufactures of the seals would disagree. The shelf life of nitrile is 10-15 years depending on which manufacture’s recommendations you follow. And EPDM and viton are stable enough to have an indefinitely long shelf life. Those three materials are the ones that are in most modern regulators. Drying and cracking may have been an issue with regulators manufactured in the 1970s or earlier when less durable elastomers were in use, but drying and cracking is not an issue with 2 year old Atomics. But those are shelf life issues. The o-rings can still take a set over time when they are under load. A minor adjustment of the second stage is usually enough to resolve that.

Tht's shelf life and not used equipment. When internal parts are exposed to water, especially salt water, it's a whole different story.

 

[Couv]

I did the test, when I take off one of the second stage and plug the port, there are no leak...

OK so you are getting somewhere, now swap it out with the other one and see what you get. If it leaks, try taking off the exhaust cover and check to see if there is a problem with the exhaust valve.

 

[JenCell]

I did the test with both regulator separately and no leak...so it must be when they are together....

 

[Couv]

Keyshunter mentioned that the seat saver could be allowing air to seep in through one second stage, but not the other. Do both of your second stages have a seat saver function? If so, then I think he may have hit the nail on the head. Oddly enough, the second stage that DOES NOT leak, could be the one out of adjustment, just as he said. Especially telling is that you do not have the problem when only one second stage is hooked up at a time.

 

[JenCell]

Keyshunter mentioned that the seat saver could be allowing air to seep in through one second stage, but not the other. Do both of your second stages have a seat saver function? If so, then I think he may have hit the nail on the head. Oddly enough, the second stage that DOES NOT leak, could be the one out of adjustment, just as he said. Especially telling is that you do not have the problem when only one second stage is hooked up at a time.

Yes all atomic have a seat saver. but why If I hook up one stage at a time, there are no leak?...it means that the seat saver of both stage are ok....there are not supposed to let air passed, am I correct (thanks a lot for all your answer, very appreciated!!!):kiss2:

 

[Hatul]

Yes all atomic have a seat saver. but why If I hook up one stage at a time, there are no leak?...it means that the seat saver of both stage are ok....there are not supposed to let air passed, am I correct (thanks a lot for all your answer, very appreciated!!!):kiss2:

It makes sense, because when you inhale on a second stage, that stage's seat saver does nothing, it's open anyway. The problem is if you have another second stage attached to the turret, now air can enter backwards through the seat saver of that second stage and acts as a leak.

Adam

 

[Couv]

Correct Hatul,

Jen, to understand what the seat saver does and why it allows air to pass through when unpressurized it's necessary to know what the seat does in the first place. Just like the seats in your faucets, it take two to tango. There is a hard seat and soft seat that come in contact to shut off the water (in the case of a regulator it's gas). The hard seat presses into the soft seat and engraves it. A little engraving is a good thing as it makes a good tight seal where no water/gas can get by. Too much engraving is a bad thing as the soft seat will eventually have a permanent groove not filled by the hard seat and allow a leak. To lessen this engraving Atomics has incorporated the "seat saver" which separates the hard and soft seat when no pressure is applied. That is why you can draw air through it when you have both hooked up. With only one hooked up, you are creating a vacuum in the entire system-no gas can get in as you are providing a seal with your mouth on one end and the port plug on the other.

couv

 

[JenCell]

Thanks I understand better!
But why if they are hooked up together, just one let air pass?

 

[Couv]

Hi Jen,

Ah….if both second stages have a seat saver, then the one THAT DOES NOT pass air is the one that is faulting…..the hard and soft seats are making contact. Is this seat saver automatic or is there a switch/lever/knob or other device that the user sets? At any rate, this is probably no big issue but see the regulator inspection thread to and find the section where cracking pressure is discussed to perform a check. If the cracking pressure is ok, then I would not bother with it until you bring it in for it's service.

couv

 

[JenCell]

thanks....The seat saver are automatic, if there's no pressure, no contact, if there's pressure there is a contact.