Hog d1 ip high

[Candiru]

I’m working on a hog D1. The last service was two years ago. The IP is currently 155. I had set the IP at 135 at the last service. No Creep no other issues. My plan is to lower the IP to 135 via the adjustment screw. Any issues with doing this?

 

[undrwater]

I’m working on a hog D1. The last service was two years ago. The IP is currently 155. I had set the IP at 135 at the last service. No Creep no other issues. My plan is to lower the IP to 135 via the adjustment screw. Any issues with doing this?

I'm going to lurk and learn, but I'm confused how the IP went from 135 to 155 without creep.

 

[Candiru]

Right, so when I initially serviced the reg I set it at 135. Now it’s at 155. This is where it locks. It’s not creeping from 135 to 155.

 

[Candiru]

I assume it either the seat or the spring breaking in.

 

[rsingler]

As the HP seat oring dries and lube dissipates, action becomes fractionally more sluggish, allowing more time until the valve closes. This allows more tank pressure into the intermediate chamber, and IP rises.

Seat indentation also allows fractionally more travel, with the same result.

That said, 20 psi is a bit more than one would expect.

 

[Candiru]

Seat indentation

 

[Candiru]

So is it reasonable to adjust and not rebuild?

 

[tbone1004]

if it adjusts back down to normal and stays there, then leave it. When was the last service?

 

[Fibonacci]

Could also be lubricant related... maybe o-rings a bit dry?
I noticed one Atomic Z2 IP inexplicably creeping a bit 125-135psi with a brand new seat and unmarked piston.
Turns out they are rather finicky with lubricant... a smear of Dow 111 on the piston stem when assembling was the culprit, viscosity was too high vs the specified Christolube/Tribolube 71.
Learned a lesson there, cleaned off the 111 and relubricated with Tribolube 71... the IP was then rock solid at 125psi and snapped consistently back to that point.

 

[Candiru]

if it adjusts back down to normal and stays there, then leave it. When was the last service?

Last service was two years ago. Probably close to 40 hours underwater. Used as a redundant stage.