FX Installed a Huma 1st Stage Reg on Impact M3, now it won't degass. Any Ideas?

[TheDaleness]

UPDATE:
To degas the system when you have a Huma 2nd reg there are 2 options:
1. dry fire till the plenum is empty. Sometimes it will start draining after 2-5 shots, other times you will need to dry fire until the system is empty.

2. You can very slowly unscrew the 2nd stage reg gauge until the air starts to drain. BUT be careful. You can damage the X-ring under the gauge if there is not enough silicone lube between the gauge and the x-ring. Also, if there is not enough lubricant on the gauge threads then the friction can damage them. If you can't unscrew the gauge by hand then keep dry firing the gun till you can.

HUMA'S ANSWER TO MY QUESTION:
"Unlike FX, we use a floating seal, which will keep sealing the low pressure side of the regulator even when doing shots or increasing reg pressure. So you can't drain the gun as you were used to on the standard fx reg. Dry firing the gun till the plenum is empty is the recommended method for degassing."


ORIGINAL POST:
On my Impact M3 I switched out the stock FX 1st stage reg with a Huma and it was working great. Decided to switch out the stock 2nd reg with a Huma. But when I tried to degass the gun to install the 2nd reg I was unable to. I did what I always do when degassing: remove the bottle then dry fire once or twice until the air starts flowing. But this time the air didn't flow after 5 dry fires. So I turned the 2nd reg screw 1/4 turn counter clockwise. Nothing.

I thought maybe this was a one-time thing. This happened once before years ago with a different FX gun and I just dry fired till the gun was empty, and it didn't happen again. So I dry fired the M3 till empty, regassed, and then tried to degas, but again the air wont flow.

Any ideas?

 

[Deadlands]

I have an impact mk2. My Huma reg won’t degas either. You can slightly unscrew your reg gauge until you hear it hiss and then let it bleed out to zero. Just inspect the X-ring under the gauge after it’s empty. Make sure it’s seated properly and lubed, and just hand tighten the gauge. Don’t crank it with your wrench or the x-ring will get squashed and deformed.

 

[Deadlands]

I’m sure others will be able to explain better but my guess is it has to do with that floating delrin disc between the set screw and piston. Without tank pressure to overcome the plenum pressure it stays sealed. My reg otherwise works as it should.

 

[mubhaur]

On my Impact M3 I switched out the stock FX 1st stage reg with a Huma and it was working great. Decided to switch out the stock 2nd reg with a Huma. But when I tried to degass the gun to install the 2nd reg I was unable to. I did what I always do when degassing: remove the bottle then dry fire once or twice until the air starts flowing. But this time the air didn't flow after 5 dry fires. So I turned the 2nd reg screw 1/4 turn counter clockwise. Nothing.

I thought maybe this was a one-time thing. This happened once before years ago with a different FX gun and I just dry fired till the gun was empty, and it didn't happen again. So I dry fired the M3 till empty, regassed, and then tried to degas, but again the air wont flow.

Any ideas?

Looks like 1st stage Huma regulator is not allowing the degassing

 

[Gerry52]

The Huma reg I installed in my Boss recently goes in BACKWARD in comparison to my old one! Could that possibly be the case? Not familiar with the workings of M3 so that might sound stupid.

 

[Ca_Varminter]

Once the Delrin Disk has set in, formed to the contour of the adjustment screw... it will not depressurize when you remove the bottle..
This due to no Pressure to push the Delrin disk away form the port hole on the adjustment screw.
In fact the Pressure that remains in the system is pushing against the Delrin Disk and Piston, Maintaining a seal!!!!
Just dry fire it a few time to drop the pressure low enough for the Delrin disk to lose it full seal....
I do this all the time, since both of my M3 have 2 Huma Regs....

 

[TheDaleness]

I have an impact mk2. My Huma reg won’t degas either. You can slightly unscrew your reg gauge until you hear it hiss and then let it bleed out to zero. Just inspect the X-ring under the gauge after it’s empty. Make sure it’s seated properly and lubed, and just hand tighten the gauge. Don’t crank it with your wrench or the x-ring will get squashed and deformed.

This worked perfectly. Even at 150 bar, the 2nd stage reg gauge unscrewed 1/8th of a turn with ease and the air drained. I checked the X-ring after the gun emptied and it was in perfect shape. The gun refilled as normal and there was no leak from the 2nd reg gauge. Thanks for the tip Deadlands!

 

[TheDaleness]

I have an impact mk2. My Huma reg won’t degas either. You can slightly unscrew your reg gauge until you hear it hiss and then let it bleed out to zero. Just inspect the X-ring under the gauge after it’s empty. Make sure it’s seated properly and lubed, and just hand tighten the gauge. Don’t crank it with your wrench or the x-ring will get squashed and deformed.

Once the Delrin Disk has set in, formed to the contour of the adjustment screw... it will not depressurize when you remove the bottle..
This due to no Pressure to push the Delrin disk away form the port hole on the adjustment screw.
In fact the Pressure that remains in the system is pushing against the Delrin Disk and Piston, Maintaining a seal!!!!
Just dry fire it a few time to drop the pressure low enough for the Delrin disk to lose it full seal....
I do this all the time, since both of my M3 have 2 Huma Regs....

Thank you for the detailed explanation. Really helped me to understand what's going on in the reg.