On 22 Dec 2004 17:00:33 GMT, Ignoramus31279
wrote:

I would use Permatex High Performance thread sealant, sold at NAPA.
It comes in a tube. A little pricey, but it comes well recommended by
a mechanic friend of mine.

Tom

I am installing a bunch of 1/8" NPT fittings into an engine (26 year
old Onan DJE generator). I would like to make sure that, no matter
what, the engine oil sealed off by the fittings, does not spill.

Should I use teflon tape (which is a hassle), or is there some nice
compound that I can put on threads?

thanks


i

Ignoramus31279 wrote:
I am installing a bunch of 1/8" NPT fittings into an engine (26 year
old Onan DJE generator). I would like to make sure that, no matter
what, the engine oil sealed off by the fittings, does not spill.

Should I use teflon tape (which is a hassle), or is there some nice
compound that I can put on threads?

I don't use that tape much any more. It does nothing to prevent issues
from dissimilar metals, it often is pushed completely out of the area
where it needs to be, it shreds up in little fragments and winds up in
an air stream or fluid, and it doesn't help seal. In fact, I'm not sure
what it *does* do.

I like RectorSeal or maybe Rector's. Any good hardware store or plumbing
supply place or even (shudder) Homo Depot or Lowe's should have it.

GWE

On Wed, 22 Dec 2004 10:31:00 -0800, Grant Erwin
wrote:

Ignoramus31279 wrote:
I am installing a bunch of 1/8" NPT fittings into an engine (26 year
old Onan DJE generator). I would like to make sure that, no matter
what, the engine oil sealed off by the fittings, does not spill.

Should I use teflon tape (which is a hassle), or is there some nice
compound that I can put on threads?

I don't use that tape much any more. It does nothing to prevent issues
from dissimilar metals, it often is pushed completely out of the area
where it needs to be, it shreds up in little fragments and winds up in
an air stream or fluid, and it doesn't help seal. In fact, I'm not sure
what it *does* do.

IIRC teflon tape is primarily for plumbers. I've used it very
successfully on plumbing fittings, especially metal-to-plastic fits on
swimming pool stuff.

--RC


I like RectorSeal or maybe Rector's. Any good hardware store or plumbing
supply place or even (shudder) Homo Depot or Lowe's should have it.

GWE

"Sometimes history doesn't repeat itself. It just yells
'can't you remember anything I've told you?' and lets
fly with a club.
-- John W. Cambell Jr.

In article ,
Ignoramus31279 wrote:

I am installing a bunch of 1/8" NPT fittings into an engine (26 year
old Onan DJE generator). I would like to make sure that, no matter
what, the engine oil sealed off by the fittings, does not spill.

Should I use teflon tape (which is a hassle), or is there some nice
compound that I can put on threads?

thanks


i

For stuff like that I've been using plain old Permatex #2 gasket sealer
as long as I can remember... with zero leaks. Most any auto parts store
should carry it. It's good stuff to have around.

Beware of Permatex #1 if you ever plan to clean up around the site... I
don't even allow #1 in my shop anymore... horrible stuff to scrape off.
I guess there are some applications where it's preferable, but couldn't
imagine what they'd be.

Good Luck!

Erik

Hi Temp silicone sealant never fails me.

Tony
"Ignoramus31279" wrote in message
...
I am installing a bunch of 1/8" NPT fittings into an engine (26 year
old Onan DJE generator). I would like to make sure that, no matter
what, the engine oil sealed off by the fittings, does not spill.

Should I use teflon tape (which is a hassle), or is there some nice
compound that I can put on threads?

thanks


i

I used to rebuild air compressors for heavy trucks and buses and
earthmoving equipment. One of the more common reasons for compressor
failure was silicone sealant. If it managed to get into the oil feed
port when it was used on the 1/8" NPT fitting, it would break off and
get into the small oil passages in the crank, shut off the oil, and
blow the compressor to bits. We heard of entire $40,000 engines shot
because the compressor shattered and the engine oil went overboard and
starved the engine. Guys would use silicone on the mounting gasket,
through which the oil drain port passes, and this would plug up and
cause similar failure.
After 17,000 compressors, this was my advice: Use Loctite 242
(blue stuff) on pipe fittings, and Permatex Hi-Tack gasket sealant on
gaskets. Silicone belongs around bathtubs, or in non-critical
automotive applications.

Dan

On 23 Dec 2004 08:31:53 -0800, wrote:

I used to rebuild air compressors for heavy trucks and buses and
earthmoving equipment. One of the more common reasons for compressor
failure was silicone sealant. If it managed to get into the oil feed
port when it was used on the 1/8" NPT fitting, it would break off and
get into the small oil passages in the crank, shut off the oil, and
blow the compressor to bits. We heard of entire $40,000 engines shot
because the compressor shattered and the engine oil went overboard and
starved the engine. Guys would use silicone on the mounting gasket,
through which the oil drain port passes, and this would plug up and
cause similar failure.
After 17,000 compressors, this was my advice: Use Loctite 242
(blue stuff) on pipe fittings, and Permatex Hi-Tack gasket sealant on
gaskets. Silicone belongs around bathtubs, or in non-critical
automotive applications.

Dan

This is the same reason I WILL NOT use teflon tape on air lines on CNC
machinery. Ive pulled too many solenoids apart where the shuttles or
even drip lubricators were plugged off with a bit of teflon tape. Some
of those air holes are very small, and plugging them off will cause
starvation some place in the system, and if the operator is not aware
of, or doesnt know...will cau$e $omething expen$ive to fail.

I use teflon pipe dope paste. Works fine, tastes great, less filling
G

Gunner

"Gunner, you are the same ridiculous liberal f--k you ever where."
Scipio

"Grant Erwin" wrote in message
...


I don't use that tape much any more. It does nothing to prevent issues
from dissimilar metals, it often is pushed completely out of the area
where it needs to be, it shreds up in little fragments and winds up in
an air stream or fluid, and it doesn't help seal. In fact, I'm not sure
what it *does* do.

GWE

Grant
Teflon tape is not a sealant it is a lubricant. It is used to lubricate
tapered pipe threads so that they will tighten easily without galling and
seal as designed. IN CASE SOME ONE MISSED THE POINT TEFLON TAPE IS A
LUBRICANT!
lg
no neat sig line

In article , larry g says...

Teflon tape is not a sealant it is a lubricant. It is used to lubricate
tapered pipe threads so that they will tighten easily without galling and
seal as designed. IN CASE SOME ONE MISSED THE POINT TEFLON TAPE IS A
LUBRICANT!

Well, here's one vote for just plain 'ol teflon tape. I've
used it for years, for all kinds of gas/water/vacuum applications,
and never had any trouble with it.

Properly applied it will produce a helium mass-spec leak tight
connection with NPT fittings - brass, stainless, copper, or
any combination of the above.

The other kinds of pipe dope compounds work too, like the SWAK
with PTFE particles in it. But I find the teflon tape to be
neater and more reliable.

Jim


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On 23 Dec 2004 17:38:58 -0800, jim rozen
wrote:

In article , larry g says...

Teflon tape is not a sealant it is a lubricant. It is used to lubricate
tapered pipe threads so that they will tighten easily without galling and
seal as designed. IN CASE SOME ONE MISSED THE POINT TEFLON TAPE IS A
LUBRICANT!

Well, here's one vote for just plain 'ol teflon tape. I've
used it for years, for all kinds of gas/water/vacuum applications,
and never had any trouble with it.

Properly applied it will produce a helium mass-spec leak tight
connection with NPT fittings - brass, stainless, copper, or
any combination of the above.

The other kinds of pipe dope compounds work too, like the SWAK
with PTFE particles in it. But I find the teflon tape to be
neater and more reliable.

Jim

Except with stainless on stainless. It doesn't always prevent
galling. The stuff for that is Loctite PST.

Pete Keillor

In article , Peter T. Keillor III
says...

Well, here's one vote for just plain 'ol teflon tape. I've
used it for years, for all kinds of gas/water/vacuum applications,
and never had any trouble with it.

Properly applied it will produce a helium mass-spec leak tight
connection with NPT fittings - brass, stainless, copper, or
any combination of the above.

The other kinds of pipe dope compounds work too, like the SWAK
with PTFE particles in it. But I find the teflon tape to be
neater and more reliable.

Except with stainless on stainless. It doesn't always prevent
galling. The stuff for that is Loctite PST.

I've used it for stainless on stainless NPT fittings. You are
correct that it is unwise to try to dismantle and re-use that
combination - but a properly made-up fitting set like that
will seal just fine with teflon tape.

Jim


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==================================================
please reply to:
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==================================================

jim rozen wrote:

In article , Peter T. Keillor III
says...

Well, here's one vote for just plain 'ol teflon tape. I've
used it for years, for all kinds of gas/water/vacuum applications,
and never had any trouble with it.

Properly applied it will produce a helium mass-spec leak tight
connection with NPT fittings - brass, stainless, copper, or
any combination of the above.

The other kinds of pipe dope compounds work too, like the SWAK
with PTFE particles in it. But I find the teflon tape to be
neater and more reliable.

Except with stainless on stainless. It doesn't always prevent
galling. The stuff for that is Loctite PST.

I've used it for stainless on stainless NPT fittings. You are
correct that it is unwise to try to dismantle and re-use that
combination - but a properly made-up fitting set like that
will seal just fine with teflon tape.

Jim

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==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

I agree Jim, my day job is process instrumentation, mostly online GC's.
It's all pretty much SS tubing, from 1/16" up to 1/2". All the NPT
fittings get teflon tape, and properly applied easily seals 3000 psi He
and H2. Galling is a problem with the regular teflon tape but lately
we've been using a nickel impregnated type. That's all but eliminated
galling for us. The teflon paste stuff works well, but as you say can be
messy, and I find if one doesn't allow it to set up overnight one ends
up with weepy joints.

Paul
--
-----------------------------------------
It's a Linux world....well, it oughta be.
-----------------------------------------

In article , Paul Batozech says...

I agree Jim, my day job is process instrumentation, mostly online GC's.
It's all pretty much SS tubing, from 1/16" up to 1/2". All the NPT
fittings get teflon tape, and properly applied easily seals 3000 psi He
and H2. Galling is a problem with the regular teflon tape but lately
we've been using a nickel impregnated type. That's all but eliminated
galling for us. The teflon paste stuff works well, but as you say can be
messy, and I find if one doesn't allow it to set up overnight one ends
up with weepy joints.

Probably most of those fittings are swagelock, or VCR though,
right? I do a fair amount of rough-n-ready vaccum work in my
line (cryogenics) and there's almost always some NPT stuff
somewhere along the line. The teflon tape has always worked
fine. I've never come across nickel impregnated though, I'll
keep my eyes out.

Jim


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jim rozen wrote:


Probably most of those fittings are swagelock, or VCR though,
right? I do a fair amount of rough-n-ready vaccum work in my
line (cryogenics) and there's almost always some NPT stuff
somewhere along the line. The teflon tape has always worked
fine. I've never come across nickel impregnated though, I'll
keep my eyes out.

Jim

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please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

Even though most of what we use is tubing, and you're correct, Swagelock
or equivalent compression fittings predominate, nearly all the
regulators, filter housings, rotameters, and valves come with NPT
porting. Inside most of the instruments themselves it's all compression
fittings, but the sample transport and conditioning systems exterior to
the instrument, while tubing, employ plenty of tube to NPT adapters. We
also use a lot of instrumentation pipe fittings, tees, nipples etc. that
are also NPT.

The nickel bearing teflon tape we use is made by Federal Process
Corporation, Pt# SA26. There phone is 800-846-7325 and
www.federalprocess.com. I know this on Christmas day only because I
happened to find a part roll in the pocket of my work coat.

Paul

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It's a Linux world....well, it oughta be.
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On Sat, 25 Dec 2004 19:34:56 GMT, Paul Batozech
wrote:

jim rozen wrote:


Probably most of those fittings are swagelock, or VCR though,
right? I do a fair amount of rough-n-ready vaccum work in my
line (cryogenics) and there's almost always some NPT stuff
somewhere along the line. The teflon tape has always worked
fine. I've never come across nickel impregnated though, I'll
keep my eyes out.

Jim

--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

Even though most of what we use is tubing, and you're correct, Swagelock
or equivalent compression fittings predominate, nearly all the
regulators, filter housings, rotameters, and valves come with NPT
porting. Inside most of the instruments themselves it's all compression
fittings, but the sample transport and conditioning systems exterior to
the instrument, while tubing, employ plenty of tube to NPT adapters. We
also use a lot of instrumentation pipe fittings, tees, nipples etc. that
are also NPT.

The nickel bearing teflon tape we use is made by Federal Process
Corporation, Pt# SA26. There phone is 800-846-7325 and
www.federalprocess.com. I know this on Christmas day only because I
happened to find a part roll in the pocket of my work coat.

Paul

That stuff sounds interesting. I work in a research and small scale
production environment, so we use a lot of ss tubing. Something to
watch out for with the tape as well is to avoid leaving any tendrils
or scraps at the fitting ends that could get into your instruments.
Since we reconfigure a lot, the galling is an issue that made me give
up on regular teflon tape. The PST stuff works great, but can be
messy. I've had no problems with leaks.

On the sanitary stuff (production and pilot scale), we use a sanitary
rated white paste, but npt is rare on that due to being difficult to
clean without disassembly. Most is orbitally welded polished tubing
with triclamps. Most gauges and instrumentation are fitted on Wika
seals, which are annular smooth bore flow through seals.

Pete Keillor