Keg hissing when gas-in QD connected

[chillaxis]

Hey all. I have a pin-lock corny keg with a weird problem: the keg hisses and leaks gas when the gas-in quick disconnect is connected. It holds pressure just fine when I disconnect the gas line, but as soon as I reconnect it it starts hissing again.

The weird thing is that I've replaced almost every component of this setup in an attempt to solve the issue: I've replaced the quick disconnect, the entire gas-in post and poppet assembly, and the dip tube o-ring. I've lubed and fully tightened everything as well. Nothing has helped. I'd been using this keg for almost a year before this happened without any issues, but I can't figure out whats going on. Does anyone have any insights or suggestions?

 

[IslandLizard]

The poppet isn't sealing right where it meets the top of the post.

Could be a burr in the post, a piece of grit, dirt or fabric fibers stuck in the spring/seal, or just the wrong size or shape of that rubber seal.

There are 3 legs on the bottom of the poppet. They have to either secure in the post (best) or sit on top of the dip tube flange (not always stable). If it's loose, off center, or not straight up it won't seal.

 

[day_trippr]

It's not the poppet.

Once the QD is in place the poppet does nothing to affect the seal. You could literally throw the poppet in the trash and it won't affect the seal between the disconnect and the post.

More likely the O-rings used weren't meant for pin lock kegs. A common error, even places like Morebeer sell the same O-rings for either style. Which is incorrect: pin lock keg post O-rings are thicker than ball lock O-rings.

http://www.chicompany.net/index.php?main_page=product_info&cPath=376_1_163&products_id=3286

Cheers!

 

[b-boy]

I agree with the o-ring theory. I bought some online that were a tiny bit too big. When I would put on the gas-in connection it would distort the o-ring and leak. I bought new o-rings and it took care of the problem. Does the qd go on smoothly, or do you have to force it on?

 

[IslandLizard]

It's not the poppet.

Once the QD is in place the poppet does nothing to affect the seal. You could literally throw the poppet in the trash and it won't affect the seal between the disconnect and the post.

More likely the O-rings used weren't meant for pin lock kegs. A common error, even places like Morebeer sell the same O-rings for either style. Which is incorrect: pin lock keg post O-rings are thicker than ball lock O-rings.

http://www.chicompany.net/index.php?main_page=product_info&cPath=376_1_163&products_id=3286

Cheers!

You're absolutely right. I misread the OP, leaking while "quick disconnect is connected..."