PDA

View Full Version : another burst disc issue/Tom



be4meliz
04-21-2011, 03:55 PM
Tom, I also have the same issue as ABDA- have taken apart several times and cleaned off burst disc and used pipe tape, but is leaking through vent. Would like another burst disc- this unit worked fine for ~ 10 hrs run time- no other leaks.
My shipping addy is:570 Farrington Rd.
Barre, Ma. 01005
Sincerely,
Stephen Rall

rsterne
04-21-2011, 06:12 PM
Burst discs do not seal on the threads as they are not pipe thread and therefore teflon tape will not help.... They are 3/8-24 NF and seal against the bottom of a shouldered (square bottomed) hole.... When you remove the burst disc you should see a shiny ring where the soft copper seal has crushed slightly against the bottom of the hole....

Bob

TomKaye
04-21-2011, 11:01 PM
Do you have a 4500 or 3000? We will send it out next week.

Tom

JSB
04-22-2011, 12:33 AM
Burst discs do not seal on the threads as they are not pipe thread and therefore teflon tape will not help.... They are 3/8-24 NF and seal against the bottom of a shouldered (square bottomed) hole.... When you remove the burst disc you should see a shiny ring where the soft copper seal has crushed slightly against the bottom of the hole....

Bob
[Please no flame war]
According to a very experienced HVAC union pipe fitter.... teflon tape does not seal... it acts a lubricant to make the the threads seal. So the tape should help to make the seal as you explain.

http://en.wikipedia.org/wiki/Thread_seal_tape

Pipe dope is another story.

JSB

TomKaye
04-22-2011, 12:45 AM
Sealing the threads on a burst disk will still cause it to leak past the copper disk if not seated properly.

Tom

rsterne
04-22-2011, 02:58 AM
Yup, that was my point....

Bob

Abda
05-05-2011, 08:51 AM
Yup, that was my point....

Bob

Yea, this I can atest personally. After using the teflon tape to try to correct the problem I ended up stripping the threads where the burst disk inserts.

I DO NOT recomend using teflon tape to try to fix this problem *if* you have, in fact, have encountered a Burst Disk leak issue.

In my opinion, if I hadn't of used teflon tape to fix my problem I wouldn't have over tightened the nut to the point that I stripped it out. This was MY fault entirely.

The infamous voice of experience speaks.

But, with a little work and easy enough to do, I got mine back up and working. I'm glad too . . . Don't know what I'd do without my shoebox!:)

I love my Shoebox!