Canadian Airgun Forum

Al, thank you.

Did the tube swell at the oring seal? any flaring at all?

That is not how I would make the seal and the number of threads makes me go mmmmmmmm.
Good to see it passed for sure.

Walter....

_________________

Walter

To be honest, I didn't measure the o-ring sealing area...was focused on the threaded area.

Measured it up just now, it's out of round by a couple thou. Had it yielded, I would expect it to be round. Will re-do the test paying attention to this area if you would like. Could do it tomorrow.

There is some prior "mechanical" damage to the lip of the tube that might be a contributing factor to its being out of round.

Al

I'm certainly no expert, but IMO it,s over built. Add,s a lot of unnecessary weight.

_________________
Eun Jin Sumatra 2500 .22 cal
Hammerli Pneuma .177 cal
Diana 34 panther .22 cal
Ruger air hawk .177 cal
QB 88 .22 cal
Beeman silver bear .177 cal
Crosman 2240 .177 and .22 cal
Hatsan mod 25 .177 cal

Al that wouldbe swell. The oring seal is the weakest part of the tube for sure. If you could measure that while pressured?

Why did RR weld that thing up? mmmmmm is it destroyed or can you lathe that booger off?

Would expect an oringed plug down inside for testing of all units without the weld.

Walter....

_________________

Walter

Will get at it tomorrow. Measuring under pressure is not a problem.

I was told the unit was welded for a pressure test carried out by RR and company. Should be able to remove/clean up the weld...won't know for certain until I give it a go.

Al

Hipac was under test for another afternoon today.

Measured at the o-ring seal and @ 5000psi, there was .002" growth. Of moderate interest, and somewhat perplexing...although growth was uniformly .002"...the out of round condition persisted.

I released the pressure after 3 1/2 hrs, will measure in the morning to see if it yielded or not.

Al

O-ring area measures .001" greater than before the test.

I did my initial measurement of this area prior to assembling the unit, so I am going to run the test again without disassembly to rule out expansion due to assembly torque/o-ring compression...wouldn't think it an issue as it's only hand tight, but we'll see.

Al

Ran the test again, this time without disassembling the unit. As expected, it did grow under pressure...to the same point as the previous test.

After letting it sit overnight with the pressure off, it was measured without disassembling. Measurements are the same after the previous test. This would seem to indicate no yield failure.

I'm being forced to conclude that while "only" hand tight, compressing the o-ring is generating enough force to cause .001" deformation. Threads ARE amazing force multipliers...it's what allows you to lift a car with a simple screw jack.

I'm at a loss to think of any other explanation at this time. I had to use a strap wrench and soft jaws to get it apart initially...perhaps over tightening is to blame for the slight belling at the lip??

Anyone have any alternate insight on this? Proving interesting at any rate.

Al

Sure, i have some insight as to the out-of-round. I had to disassembly it at one point and it slipped in the vise, i over tightened and squeezed it. We used it for testing since it wouldn't install. Opening the exhaust end it'll test like every other HiPAC out there.

Glad to see you got 5Kpsi. We were only able to get 4700

This is where i say, "Now you all know what we've always known"

PEACE

_________________
www.PowerMax-HiPAC.com

PowerMax-HiPAC Owners Forum