RE: [PSUBS-MAILIST] Tapered Threads

["Jay K. Jeffries" <bottomgun@mindspring.com>]

James,
While as you noted the taper thread will go into a straight threaded hull
you will not have many threads fully engaged.  Under pressure this fitting
may blow off over time.  You are best served by screwing the Swagelok
fitting into the proper corresponding straight threaded receiver.
R/Jay

Respectfully,
Jay K. Jeffries
Andros Is., Bahamas

As scarce as the truth is, the supply has always been in excess of the
demand. 
    -Josh Billings



-----Original Message-----
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of James Frankland
Sent: Sunday, October 19, 2008 6:18 AM
To: personal_submersibles@psubs.org
Subject: [PSUBS-MAILIST] Tapered Threads

Hi All.

Can anyone help me with this minor thing.

I'm making the VBT and i had the threads cut on a special threading machine.
See this picture.

http://guernseysubmarine.wordpress.com/

Anyway, the 1 inch valve has a tapered thread, so i have cut the thread on
the pipe accordingly to have the same taper.  It fits perfect and will screw
up nice and tight.  

But, the little 1/2 inch swagelok fitting has a straight thread inside.  So
i cut one end of the pipe tapered thread and the other straight.  Im not
sure which to use.  If i screw on the tapered thread, it will tighten up but
i'm nto sure if thats right as i feel its only tightening on the end of the
taper.  But if i use the straight thread, it screws down right to the end
and is it going to seal properly?  I feel as if there should be a rubber or
fibre washer in the end of the swagelok fitting to seal the straight thread.
There isnt one but i can make one easy enough.  

Any ideas?  Taper or non taper.  Washer? 

Thanks
James





************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003.  Your email address appears in our database
because either you, or someone you know, requested you receive messages
from our organization.

If you want to be removed from this mailing list simply click on the
link below or send a blank email message to:
	removeme-personal_submersibles@psubs.org

Removal of your email address from this mailing list occurs by an
automated process and should be complete within five minutes of
our server receiving your request.

PSUBS.ORG
PO Box 53
Weare, NH  03281
603-529-1100
************************************************************************
************************************************************************
************************************************************************