Regulators ‘breathe’ w/o air?

[Aloha Joe]

I have SP R109 and G250 regs. I’m able to breath through both of them on the bench, as if the cracking pressure is just set pretty low. When my regs were initially serviced by a tech, I could pull hard and not get any air. I’ve since been servicing my own regs and the G250 has been working fine (R109 hasn’t been used yet).

Is this just me experiencing quality regs that are properly set, and the tech had left them with a considerable safety factor? When searching how to buy used regs, I saw many comments that regs should not ‘breathe’ on the bench, so I’m confused.

 

[halocline]

Are you talking about breathing off them not attached to a tank? With no hose or 1st stage attached, you should be able to pull some air through the 2nd stages, nothing like they breathe when pressurized.

With hoses and a first stage attached, if the dust cap is installed, you should get zero air, otherwise you have a leak somewhere. If the dust cap is not installed, you should be able to pull a bit of air through the open first stage and hoses.

You do understand that the 2nd stages are designed to breathe correctly when they are pressurized at about 130PSI (give or take)? I'm just trying to figure out what exactly you are asking.

 

[Aloha Joe]

Thank you. Your first comment answered my question - with no hose attached, I should be able to pull some air through the second stage.

 

[northernone]

Thank you. Your first comment answered my question - with no hose attached, I should be able to pull some air through the second stage.

Happened to be going through our program regs for the summer. For curiosity, I just pulled a breath through the second stage (no hose) of 9 different brands/models. It's normal.

Cracking pressure and reg tuning is another topic and needs tested pressurized. I can't tell the difference sucking on a bare reg at all.

Cameron

 

[Aloha Joe]

I must have read that ‘full reg assemblies’ should not breathe on the bench but misunderstood it. Thanks for setting me straight. My regs pass all the tests when pressurized.