We have used Swagelok extensively with LOX and HTP for small diameters. I
can't think of any examples where we used NPT fittings with sealants of any
kind with those oxidizers. There are a few examples where test points were
sealed with PTFE tape and NPT fittings but nothing for delivery come to
mind. There are some rocket plumbers on this list that do this more
routinely than I do nowadays.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf
Of Rick Wills
Sent: Friday, March 27, 2020 8:04 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Swagelok and LOX
Hi
Has anyone on the list used Swagelok compression fittings in service with
LOX (3/4 or 1 in)? I've used AN (37 deg flare) and NPT fittings
successfully for LOX. NPT fittings are wrapped with PTFE tape. My entire
LOX side on my test stand is all AN expect for the NPT adapters used on the
main LOX valve and LOX load valve. Any LOX experience with any other brand
of compression fittings (Parker, etc). I'm looking at changing the stand
plumbing and am considering Swagelok. Check out our Facebook page
https://www.facebook.com/midwestpropulsiongroup to see the stand in action.
The Army missile spec forbids NPT fittings. Most likely reason is they
could vibrate loose. I've seem amateur liquid systems using NPT fittings
successfully. Any advice would be appreciated. On my first test stand, I
welded the NPT fittings together. It worked but looked pretty bad. An A&P
I know suggested safety wiring the NPTs so they would come loose. That is a
lot of work.
I'm lucky. My outbuilding is also my rocket workshop. When I want to
escape I run out back for a few hours. Thanks and everyone take care.
Be Safe,
Rick Wills
Huber Heights, Ohio