"Upscale" wrote in message
This time they're all copper as recommended.

Correction, should have said brass.

"Upscale" wrote in message
...

"LD" wrote in message
know how loud this 85db compressor sounds compared to the old one that
I'm
giving to a friend.

What did you use on the old one?

Nothing. Didn't occur to me when I bought it some ten years ago. And yes,
there was a small, discernable hiss right at the point of air exiting
whatever male adapter I had inserted. Also, all the adapters appeared to
be
some type of silver coloured alloy. This time they're all copper as
recommended.



FWIW, the compressor manufacturers say teflon tape. IIRC, Cambell Hausefeld
includes a roll.

Upscale wrote:
I've just picked up a new portable compressor, hose and an array of fittings
~ all connections will be brass to brass. Do I need plumber's tape for these
fittings or should I be fine with just the brass to brass? I was wondering
what others have done?

Jack Stein wrote:
I don't see any need for tape or dope on compression fittings.

Doug Miller wrote:
Compressed air fittings are not the same as compression fittings.

Brass compression fittings certainly are common compressed air fittings?

Non-compression fittings need tape or dope regardless of what they are
made of?

Tape or dope should be used for all fittings for ease of proper assembly.

Nope. Tape or dope is not needed at all for brass compression fittings
commonly used in air lines, water lines etc.

The joint won't seal unless it's tight, and the tape or dope reduces
friction,
making it easier to get the joint tight. And it's pretty much mandatory for
anything that might be disassembled later.

I don't agree, brass compression fittings can easily be overtightened,
and dope/tape could facilitate that. Also, tape/dope could contaminate
the compression fitting resulting in leakage. Other than that, using
dope/tape on a brass compression fitting is pretty much meaningless. If
the oval ring in a compression fitting leaks, all the pipe dope or tape
in the world will not help it, and a new ring/fitting is needed.

Tape/Dope should always be used on non-compression fitting, for the
reasons you site. The original poster said only brass to brass, and
didn't specify compression or non compression fittings.

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

In article , Jack Stein wrote:


Upscale wrote:
I've just picked up a new portable compressor, hose and an array of
fittings
~ all connections will be brass to brass. Do I need plumber's tape for
these
fittings or should I be fine with just the brass to brass? I was wondering
what others have done?

Jack Stein wrote:
I don't see any need for tape or dope on compression fittings.

Doug Miller wrote:
Compressed air fittings are not the same as compression fittings.

Brass compression fittings certainly are common compressed air fittings?

??

Non-compression fittings need tape or dope regardless of what they are
made of?

Tape or dope should be used for all fittings for ease of proper assembly.

Nope. Tape or dope is not needed at all for brass compression fittings
commonly used in air lines, water lines etc.

Compression fittings are not at all common on air lines in my (admittedly
limited) experience.

The joint won't seal unless it's tight, and the tape or dope reduces friction,
making it easier to get the joint tight. And it's pretty much mandatory for
anything that might be disassembled later.

I don't agree, brass compression fittings can easily be overtightened,
and dope/tape could facilitate that. Also, tape/dope could contaminate
the compression fitting resulting in leakage. Other than that, using
dope/tape on a brass compression fitting is pretty much meaningless. If
the oval ring in a compression fitting leaks, all the pipe dope or tape
in the world will not help it, and a new ring/fitting is needed.

Where have you seen air lines with compression rings in the fittings?

Tape/Dope should always be used on non-compression fitting, for the
reasons you site. The original poster said only brass to brass, and
didn't specify compression or non compression fittings.

Somebody wrote:

I don't see any need for tape or dope on compression fittings.

Compression fittings require a metal to metal fit to work properly,
thus tape or dope defeats the purpose except on the threaded portion
of the fitting.

That said, compression fittings are a poor choice where high flow
rates may be required.

Lew
..

On Jul 7, 9:42*pm, "Lew Hodgett" wrote:
"Upscale" wrote:
I've just picked up a new portable compressor, hose and an array of
fittings
~ all connections will be brass to brass. Do I need plumber's tape
for these
fittings or should I be fine with just the brass to brass?

If you are referring to teflon tape, avoid it like the plague.

You want teflon paste.

Yes, you want to seal the thread connections.

Any difference between plumber's dope and gasline dope?

"Father Haskell" wrote:

Any difference between plumber's dope and gasline dope?

These days Teflon paste serves both applications.


Lew

On 2009-07-11, Lew Hodgett wrote:

"Father Haskell" wrote:

Any difference between plumber's dope and gasline dope?

These days Teflon paste serves both applications.

I don't think you can get high huffing PTFE.

nb

"Leon" wrote in message
YELLOW- Double Density- yellow double density is often labeled as "Gas
type"

Ok, I picked up a roll of the yellow tape today, but reading the
instructions on the back a little more closely, I'm not sure if I should use
it or if it's usable for my 150 psi compressor.

Here's what I got:

It's certainly yellow. The front description states "Gasline thread seal
tape".
On the back in finer print it states "Do not use on flared threads".
And then the following blurb:
"Got use in assemblies handling gasoline, petroleum oils, propane, butane
and natural gas not exceeding 100 psig".

I'm guessing that 100 psig is gallons volume, so I'm not so concerned there,
but the threads on the brass fittings *are* flared which to me means that
the circumference gets gradually larger on the male part of the fittings. I
guess I'll use it anyway since the only realistic problem I might get if
there is one is the hiss of a little air.

Thanks

"Upscale" wrote:

Ok, I picked up a roll of the yellow tape today, but reading the
instructions on the back a little more closely, I'm not sure if I
should use
it or if it's usable for my 150 psi compressor.

Here's what I got:

It's certainly yellow. The front description states "Gasline thread
seal
tape".
On the back in finer print it states "Do not use on flared threads".
And then the following blurb:
"Got use in assemblies handling gasoline, petroleum oils, propane,
butane
and natural gas not exceeding 100 psig".

I'm guessing that 100 psig is gallons volume, so I'm not so
concerned there,
but the threads on the brass fittings *are* flared which to me means
that
the circumference gets gradually larger on the male part of the
fittings. I
guess I'll use it anyway since the only realistic problem I might
get if
there is one is the hiss of a little air.

======================================
You are confusing oranges and apples.

In the USA, pipe threads are NPT (National pipe thread) which are
tapered 1-1/2"/12".

For comparison, the Brits use BSP or straight (non tapered) pipe
threads.

PSIG = Pounds per square inch gauge

Has nothing to do with volume, describes pressure..

"Flare" fittings involve flaring the copper tubing (usually 37-1/2
degrees) to provide a metal to metal seal which won't work if there is
Teflon tape in the middle.

The 100 PSIG limit is to advise you not use Teflon tape on high
pressure storage vessels.

IOW, for your applications, you can tuck your roll of tape under your
pillow and sleep tight tonight.

Lew

In article , "Upscale" wrote:

Ok, I picked up a roll of the yellow tape today, but reading the
instructions on the back a little more closely, I'm not sure if I should use
it or if it's usable for my 150 psi compressor.

Here's what I got:

It's certainly yellow. The front description states "Gasline thread seal
tape".
On the back in finer print it states "Do not use on flared threads".
And then the following blurb:
"Got use in assemblies handling gasoline, petroleum oils, propane, butane
and natural gas not exceeding 100 psig".

I'm guessing that 100 psig is gallons volume,

It's a pressure measurement. "psig" = "pounds per square inch guage" as
opposed to pounds per square inch absolute. To illustrate the difference,
which is of interest only to scientists, normal atmospheric pressure is 14.7
psi absolute, at which pressure a guage will read zero. For practical
purposes, "psi" and "psig" are freely interchangeable.

so I'm not so concerned there,
but the threads on the brass fittings *are* flared which to me means that
the circumference gets gradually larger on the male part of the fittings.

That would be a tapered thread. Gas-line pipe (black steel) uses tapered
threads, which actually slightly expand the fitting when the pipe is seated
properly, making a very tight seal. (If you've ever heard that gas-line
fittings should not be reused after a joint is disassembled, that's why.)

Are you sure it says "flared" and not "flare"? I could understand the latter,
in reference to flare fittings (which are used on gas-line *tubing*), but not
the former.

I
guess I'll use it anyway since the only realistic problem I might get if
there is one is the hiss of a little air.

Go ahead and use it. The warnings are all about avoiding any leaks of
dangerous substances such as "gasoline, petroleum oils, ... natural gas".
As you've already realized, since you're only using it for air, even if it
does leak that presents no danger.

In article , Jack Stein wrote:
Doug Miller wrote:

The joint won't seal unless it's tight, and the tape or dope reduces
friction,
making it easier to get the joint tight. And it's pretty much mandatory for

anything that might be disassembled later.

I don't agree, brass compression fittings can easily be overtightened,
and dope/tape could facilitate that. Also, tape/dope could contaminate
the compression fitting resulting in leakage. Other than that, using
dope/tape on a brass compression fitting is pretty much meaningless. If
the oval ring in a compression fitting leaks, all the pipe dope or tape
in the world will not help it, and a new ring/fitting is needed.

Where have you seen air lines with compression rings in the fittings?

About 30 feet from where I'm sitting? Are you suggesting compression
fittings are not used in air lines? I'm pretty certain I'm not the only
one to use a compression fitting on an air, or a gas line.

Not suggesting they're not used, just suggesting they're not common.

Anyway, if one is using a compression fitting, pipe dope or tape is not
needed, and may in fact be detrimental to the connection. I have seen
compression fittings where pipe dope was used on the joint by someone
who didn't know any better.

As long as you keep it on the threads, and off the ring, where's the harm?

In article , Jack Stein wrote:
Lew Hodgett wrote:
Somebody wrote:

I don't see any need for tape or dope on compression fittings.

Compression fittings require a metal to metal fit to work properly,
thus tape or dope defeats the purpose except on the threaded portion
of the fitting.

But, on the brass threaded portion the tape/dope is not needed, and
probably should be avoided.

That said, compression fittings are a poor choice where high flow
rates may be required.

I never heard this before, and not sure I understand why? Not saying
it's incorrect, just that I don't get it? They don't appear to restrict
flow at all?

Actually, they do. Take apart a compression joint in copper tube and take a
look.

Compression fittings are used in high pressure conditions, which I guess
would infer high flow rates?

Pressure and flow rate are completely different. Pressure is the force moving
a fluid (air, in this case) from one place to another; flow rate is the amount
of fluid moving per unit time. Most easily illustrated by example:
Low pressure, low flow rate -- the water in your rain gutters.
High pressure, low flow rate -- a mountain stream.
Low pressure, high flow rate -- the Mississippi.
High pressure, high flow rate -- Niagara Falls.

Now that I think about it, for Doug, the disconnects at the end of your
air hose are compression fittings. Not particularly the type we are
discussing but thought I'd throw that in.

Obviously a very different type from what we're discussing.

Doug Miller wrote:

The joint won't seal unless it's tight, and the tape or dope reduces friction,
making it easier to get the joint tight. And it's pretty much mandatory for
anything that might be disassembled later.

I don't agree, brass compression fittings can easily be overtightened,
and dope/tape could facilitate that. Also, tape/dope could contaminate
the compression fitting resulting in leakage. Other than that, using
dope/tape on a brass compression fitting is pretty much meaningless. If
the oval ring in a compression fitting leaks, all the pipe dope or tape
in the world will not help it, and a new ring/fitting is needed.

Where have you seen air lines with compression rings in the fittings?

About 30 feet from where I'm sitting? Are you suggesting compression
fittings are not used in air lines? I'm pretty certain I'm not the only
one to use a compression fitting on an air, or a gas line.

Anyway, if one is using a compression fitting, pipe dope or tape is not
needed, and may in fact be detrimental to the connection. I have seen
compression fittings where pipe dope was used on the joint by someone
who didn't know any better.

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

Lew Hodgett wrote:
Somebody wrote:

I don't see any need for tape or dope on compression fittings.

Compression fittings require a metal to metal fit to work properly,
thus tape or dope defeats the purpose except on the threaded portion
of the fitting.

But, on the brass threaded portion the tape/dope is not needed, and
probably should be avoided.

That said, compression fittings are a poor choice where high flow
rates may be required.

I never heard this before, and not sure I understand why? Not saying
it's incorrect, just that I don't get it? They don't appear to restrict
flow at all?

Compression fittings are used in high pressure conditions, which I guess
would infer high flow rates?

Now that I think about it, for Doug, the disconnects at the end of your
air hose are compression fittings. Not particularly the type we are
discussing but thought I'd throw that in.

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

"Doug Miller" wrote in message
...
In article , Jack Stein
wrote:
Doug Miller wrote:
Anyway, if one is using a compression fitting, pipe dope or tape is not
needed, and may in fact be detrimental to the connection. I have seen
compression fittings where pipe dope was used on the joint by someone
who didn't know any better.

As long as you keep it on the threads, and off the ring, where's the harm?

Typically compression fittings are brass which are self lubricating and the
threads do not provide any seal.

On Jul 11, 12:04*pm, "Upscale" wrote:
"Lew Hodgett" wrote in message
IOW, for your applications, you can tuck your roll of tape under your
pillow and sleep tight tonight.

Thanks Lew. I'll dream tonight of fairy princesses all draped out in yellow
Teflon tape. *

Uma is going to be ****ed!

Doug Miller wrote:

Where have you seen air lines with compression rings in the fittings?

About 30 feet from where I'm sitting? Are you suggesting compression
fittings are not used in air lines? I'm pretty certain I'm not the only
one to use a compression fitting on an air, or a gas line.

Not suggesting they're not used, just suggesting they're not common.

I guess we could argue common, not common all day and get no where. I
would guess it depends on what you are connecting together. Sometimes a
compression fitting is common, sometimes not. Air lines commonly have
flexible copper tubing for example and it is very common to use brass
compression fittings where they connect to standard pipe. You would use
pipe dope on the pipe thread, but not on the compression fitting.

Anyway, if one is using a compression fitting, pipe dope or tape is not
needed, and may in fact be detrimental to the connection. I have seen
compression fittings where pipe dope was used on the joint by someone
who didn't know any better.

As long as you keep it on the threads, and off the ring, where's the harm?

No harm other than a waste of time. Brass compression fittings simply
don't need dope on the threads. You could put pipe dope along the
entire length of pipe and do no harm, but it begs the question, why?

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

In article , Jack Stein wrote:
Doug Miller wrote:

Where have you seen air lines with compression rings in the fittings?

About 30 feet from where I'm sitting? Are you suggesting compression
fittings are not used in air lines? I'm pretty certain I'm not the only
one to use a compression fitting on an air, or a gas line.

Not suggesting they're not used, just suggesting they're not common.

I guess we could argue common, not common all day and get no where. I
would guess it depends on what you are connecting together. Sometimes a
compression fitting is common, sometimes not. Air lines commonly have
flexible copper tubing for example and it is very common to use brass
compression fittings where they connect to standard pipe. You would use
pipe dope on the pipe thread, but not on the compression fitting.

Most of the air lines I've seen are black steel. YMMV.

Anyway, if one is using a compression fitting, pipe dope or tape is not
needed, and may in fact be detrimental to the connection. I have seen
compression fittings where pipe dope was used on the joint by someone
who didn't know any better.

As long as you keep it on the threads, and off the ring, where's the harm?

No harm other than a waste of time. Brass compression fittings simply
don't need dope on the threads. You could put pipe dope along the
entire length of pipe and do no harm, but it begs the question, why?

As I've said several times before, taping or doping threads makes the joints
easier to disassemble. There's no point at all, obviously, in putting it along
the entire length of the pipe. But then, you're the only one who's suggested
doing that. g

On Sat, 11 Jul 2009 12:47:32 GMT, (Doug Miller)
wrote:

In article , Jack Stein wrote:
Doug Miller wrote:
....
Anyway, if one is using a compression fitting, pipe dope or tape is not
needed, and may in fact be detrimental to the connection. I have seen
compression fittings where pipe dope was used on the joint by someone
who didn't know any better.

As long as you keep it on the threads, and off the ring, where's the harm?

Or gain? If a compression fitting leaks, sealant on the threads won't
do a thing to help contain the leak.

Tom Veatch
Wichita, KS
USA

"Lew Hodgett" wrote in message
IOW, for your applications, you can tuck your roll of tape under your
pillow and sleep tight tonight.

Thanks Lew. I'll dream tonight of fairy princesses all draped out in yellow
Teflon tape.

Doug Miller wrote:


That said, compression fittings are a poor choice where high flow
rates may be required.

I never heard this before, and not sure I understand why? Not saying
it's incorrect, just that I don't get it? They don't appear to restrict
flow at all?

Actually, they do. Take apart a compression joint in copper tube and take a
look.

I happen to have a hunk of 3/8 copper tubing with a compression fitting
in my junk pile, which you made be go down and look at... couldn't see
any notable issues that would preclude it's usage in a high flow
situation, other than it was 3/8" in pipe. I guess there might be some
negligible constriction which is difficult to see and might be important
in super small pipe, but in normal home air systems in this discussion,
a very non-issue.

Compression fittings are used in high pressure conditions, which I guess
would infer high flow rates?

Pressure and flow rate are completely different. Pressure is the force moving
a fluid (air, in this case) from one place to another; flow rate is the amount
of fluid moving per unit time.

I tend to think that the amount of air that would flow through a 3/8"
pipe under 1000 lbs of pressure is more than would flow through the same
pipe with 2 lbs of pressure? Is that wrong? I know volume and pressure
are two different things, but I'd think one effects the other?

Most easily illustrated by example:
Low pressure, low flow rate -- the water in your rain gutters.
High pressure, low flow rate -- a mountain stream.

See, right there I don't get it? In my mind, to get high pressure you
need to restrict the flow. I don't see a mountain stream or a river as
high pressure? I admit I know next to nothing about fluid dynamics, but
thats my point... For example, if I have a high pressure hose, and put
a hole in the hose, the water will shoot out the hole into the air, and
the more pressure, the higher it will go. The mountain stream is not
shooting up in the air, just flowing... low pressure, high volume. My
mind says the only way to get high pressure in a mountain stream is to
force in through a pipe of some sort. I do realize that the deeper the
stream, the higher the pressure at the bottom of the stream from the
weight of the water.

Now that I think about it, for Doug, the disconnects at the end of your
air hose are compression fittings. Not particularly the type we are
discussing but thought I'd throw that in.

Obviously a very different type from what we're discussing.

Well, if you think about it, the main difference is a spring holds the
compression fitting together instead of threads. Pipe dope is not
needed anymore there than on a standard brass compression fitting.

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

Doug Miller wrote:

As long as you keep it on the threads, and off the ring, where's the harm?
No harm other than a waste of time. Brass compression fittings simply
don't need dope on the threads. You could put pipe dope along the
entire length of pipe and do no harm, but it begs the question, why?

As I've said several times before, taping or doping threads makes the joints
easier to disassemble. There's no point at all, obviously, in putting it along
the entire length of the pipe. But then, you're the only one who's suggested
doing that. g

I said you "could" do it, and "suggested" it would have the same value
as doping the threads in a brass compression fitting. I never suggested
one should do it. I understand pipe dope might make a threaded
steel/iron joint easier to loosen, but not in brass, brass doesn't rust,
doesn't need pipe dope to make it easier to disassemble.

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

In article , Tom Veatch wrote:
On Sat, 11 Jul 2009 12:47:32 GMT, (Doug Miller)
wrote:

In article , Jack Stein
wrote:
Doug Miller wrote:
....
Anyway, if one is using a compression fitting, pipe dope or tape is not
needed, and may in fact be detrimental to the connection. I have seen
compression fittings where pipe dope was used on the joint by someone
who didn't know any better.

As long as you keep it on the threads, and off the ring, where's the harm?

Or gain? If a compression fitting leaks, sealant on the threads won't
do a thing to help contain the leak.

Teflon tape isn't worth a toot as a sealant anyway, but it's a dandy
lubricant.

In article , Jack Stein wrote:
Doug Miller wrote:


That said, compression fittings are a poor choice where high flow
rates may be required.

I never heard this before, and not sure I understand why? Not saying
it's incorrect, just that I don't get it? They don't appear to restrict
flow at all?

Actually, they do. Take apart a compression joint in copper tube and take a
look.

I happen to have a hunk of 3/8 copper tubing with a compression fitting
in my junk pile, which you made be go down and look at... couldn't see
any notable issues that would preclude it's usage in a high flow
situation, other than it was 3/8" in pipe. I guess there might be some
negligible constriction which is difficult to see and might be important
in super small pipe,

One man's negligible is another man's noticeable, I suppose...

but in normal home air systems in this discussion,
a very non-issue.

Compression fittings are used in high pressure conditions, which I guess
would infer high flow rates?

Pressure and flow rate are completely different. Pressure is the force moving
a fluid (air, in this case) from one place to another; flow rate is the amount
of fluid moving per unit time.

I tend to think that the amount of air that would flow through a 3/8"
pipe under 1000 lbs of pressure is more than would flow through the same
pipe with 2 lbs of pressure? Is that wrong? I know volume and pressure
are two different things, but I'd think one effects the other?

No, you're not wrong, and indeed the pressure does affect the flow rate -- but
flow rate is also determined by the size of the pipe. You're going to get a
higher flow rate through a one-foot diameter pipe at 2psi than you will
through a 3/8"-diameter pipe at 1000psi.

Most easily illustrated by example:
Low pressure, low flow rate -- the water in your rain gutters.
High pressure, low flow rate -- a mountain stream.

See, right there I don't get it? In my mind, to get high pressure you
need to restrict the flow.

That's not correct.

I don't see a mountain stream or a river as
high pressure?

Steeper gradient = higher force (due to gravity).


I admit I know next to nothing about fluid dynamics, but
thats my point... For example, if I have a high pressure hose, and put
a hole in the hose, the water will shoot out the hole into the air, and
the more pressure, the higher it will go. The mountain stream is not
shooting up in the air, just flowing... low pressure, high volume. My
mind says the only way to get high pressure in a mountain stream is to
force in through a pipe of some sort.

I should have made it more clear that I meant that as an analogy to try to
make the point. I did not mean that the mountain stream is literally under
higher pressure.

I do realize that the deeper the
stream, the higher the pressure at the bottom of the stream from the
weight of the water.

Now that I think about it, for Doug, the disconnects at the end of your
air hose are compression fittings. Not particularly the type we are
discussing but thought I'd throw that in.

Obviously a very different type from what we're discussing.

Well, if you think about it, the main difference is a spring holds the
compression fitting together instead of threads. Pipe dope is not
needed anymore there than on a standard brass compression fitting.

Except that you won't be unscrewing one of those. Threaded fittings *are* from
time to time unscrewed, and doping them on assembly makes disassembly easier.

In article , Jack Stein wrote:
Doug Miller wrote:

As long as you keep it on the threads, and off the ring, where's the harm?
No harm other than a waste of time. Brass compression fittings simply
don't need dope on the threads. You could put pipe dope along the
entire length of pipe and do no harm, but it begs the question, why?

As I've said several times before, taping or doping threads makes the joints
easier to disassemble. There's no point at all, obviously, in putting it
along
the entire length of the pipe. But then, you're the only one who's suggested
doing that. g

I said you "could" do it, and "suggested" it would have the same value
as doping the threads in a brass compression fitting. I never suggested
one should do it. I understand pipe dope might make a threaded
steel/iron joint easier to loosen, but not in brass, brass doesn't rust,

Of course it doesn't rust -- but it *does* corrode in the presence of weak
acids, or salts.

doesn't need pipe dope to make it easier to disassemble.

Evidently you've never had the experience of trying to disassemble a corroded
joint in brass...

On Sat, 11 Jul 2009 19:24:12 GMT, (Doug Miller)
wrote:

In article , Tom Veatch wrote:

Or gain? If a compression fitting leaks, sealant on the threads won't
do a thing to help contain the leak.

Teflon tape isn't worth a toot as a sealant anyway, but it's a dandy
lubricant.

Or gain? If a compression fitting leaks, "lubricant" on the threads
won't do a thing to help contain the leak.

In fact, since a compression fitting can be overtightened, with
adverse effects, lubricant on the threads may be contra-indicated.
I've never encountered a compression fitting (or a flare fitting, for
that matter) where sealed or lubricated threads would be any benefit
either in assembly or disassembly.

Here, I assume we are talking about compression fittings
(http://www.plumbingsupply.com/compress.html) not tapered pipe threads
which seal by interference fit (compression) between the male and
female threads. Another post in this thread seems to blur the
distinction between those two categories.

Tom Veatch
Wichita, KS
USA

On Wed, 08 Jul 2009 02:00:54 GMT, (Doug Miller)
wrote:

In article , "Upscale" wrote:
I've just picked up a new portable compressor, hose and an array of fittings
~ all connections will be brass to brass. Do I need plumber's tape for these
fittings or should I be fine with just the brass to brass? I was wondering
what others have done?

Well, you need *some* kind of pipe dope in there, if you think you'll ever
want to take the joint apart a few years down the road. Some folks will tell
you never to use teflon tape with compressed air, but I've never had a
problem. Just make sure you apply the tape to the male threads only, and keep
it on the threads -- don't get any into the air passages.


I use teflon tape, double wrapped in a clockwise direction and do not
cover the entry thread. Carefully used, the tape will take up the
slop in the threads and provide a better seal, while not allowing the
metal to metal joint to seize.

I don't have my Machinery's Handbook in front of me but, if you refer
to it, you will find that there are a number of interference fit
thread engagement tolerances and what we too often get in offshore
fittings is a slop tolerance that is really more than it should be.

Pipe dope comes in flavors (caustic, pneumatic, hydraulic, etc) and I
think there is more chance for contamination because the wet surface
can attract gunk in what is often a dusty environment - and because
I'm more capable of keeping the entry thread clean with the tape.


Regards,

Tom Watson
http://home.comcast.net/~tjwatson1/

In article , Tom Veatch wrote:
On Sat, 11 Jul 2009 19:24:12 GMT, (Doug Miller)
wrote:

In article , Tom Veatch
wrote:

Or gain? If a compression fitting leaks, sealant on the threads won't
do a thing to help contain the leak.

Teflon tape isn't worth a toot as a sealant anyway, but it's a dandy
lubricant.

Or gain? If a compression fitting leaks, "lubricant" on the threads
won't do a thing to help contain the leak.

I didn't say that it would.

In fact, since a compression fitting can be overtightened, with
adverse effects, lubricant on the threads may be contra-indicated.
I've never encountered a compression fitting (or a flare fitting, for
that matter) where sealed or lubricated threads would be any benefit
either in assembly or disassembly.

You've evidently not had the pleasant experience of ever having to open
ten-year-old flare fittings on a propane line in a basement with a
dirt-and-cinder floor. Humidity + cinders = slightly acid environment =
corrosion; I believe that the job would have been a bit easier, had the
threads been doped when they were put together. Yes, I realize those aren't
the same as compression fittings, but the point is that brass *can* corrode,
and if it does, it *can* be much harder to disassemble than one would wish.
Doping the threads before assembly avoids that problem.

Here, I assume we are talking about compression fittings
(http://www.plumbingsupply.com/compress.html) not tapered pipe threads
which seal by interference fit (compression) between the male and
female threads. Another post in this thread seems to blur the
distinction between those two categories.

My assumption also.

Hey, guys, lets stick to topics we know something about, like electricity.



(paraphrasing a formerly prolific rw poster)

--
Better to be stuck up in a tree than tied to one.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar.org

On Jul 13, 1:36*pm, (Larry W) wrote:
Hey, guys, lets stick to topics we know something about, like electricity..

(paraphrasing a formerly prolific rw poster)

C'mon Larry, the plumbing, 'lectric & politico-religious threads allow
those who know nothing about woodworking to pontificate.

L.

Holy Crap!

72 Posts on Plumber's Tape!!!!!!!!!!!!!!!

You guys are life-deficient.

RonB

On Jul 13, 11:37*pm, "Upscale" wrote:
"RonB" wrote in message
Holy Crap!
72 Posts on Plumber's Tape!!!!!!!!!!!!!!!
You guys are life-deficient.

But, but, but.... I got to dream of women draped out in Teflon tape.

That's a life isn't it?

Good troll for a non-political question. :-)

Luigi

"RonB" wrote in message
Holy Crap!
72 Posts on Plumber's Tape!!!!!!!!!!!!!!!
You guys are life-deficient.

But, but, but.... I got to dream of women draped out in Teflon tape.

That's a life isn't it?

On Jul 14, 2:17*am, Luigi Zanasi wrote:
On Jul 13, 11:37*pm, "Upscale" wrote:

"RonB" wrote in message
Holy Crap!
72 Posts on Plumber's Tape!!!!!!!!!!!!!!!
You guys are life-deficient.

But, but, but.... I got to dream of women draped out in Teflon tape.

That's a life isn't it?

Good troll for a non-political question. :-)

Luigi

We did pretty well with a 'summer dresses' thread-jack
once.........those were the days.
Summer dresses are wonderful... unless it's on that bitch Ann Coulter,
then anything looks like a pillowcase full of doorknobs.

On Tue, 14 Jul 2009 08:24:37 -0700 (PDT), Robatoy
wrote:

On Jul 14, 2:17*am, Luigi Zanasi wrote:
On Jul 13, 11:37*pm, "Upscale" wrote:

"RonB" wrote in message
Holy Crap!
72 Posts on Plumber's Tape!!!!!!!!!!!!!!!
You guys are life-deficient.

But, but, but.... I got to dream of women draped out in Teflon tape.

That's a life isn't it?

Good troll for a non-political question. :-)

Luigi

We did pretty well with a 'summer dresses' thread-jack
once.........those were the days.
Summer dresses are wonderful... unless it's on that bitch Ann Coulter,
then anything looks like a pillowcase full of doorknobs.


u be dissin' blANNd cOOter?

dincha never think 'bout bumpin' uglies wif a 10 speed bike?



Regards,

Tom Watson
http://home.comcast.net/~tjwatson1/

Robatoy wrote:
On Jul 14, 2:17 am, Luigi Zanasi wrote:
On Jul 13, 11:37 pm, "Upscale" wrote:

"RonB" wrote in message
Holy Crap!
72 Posts on Plumber's Tape!!!!!!!!!!!!!!!
You guys are life-deficient.
But, but, but.... I got to dream of women draped out in Teflon tape.
That's a life isn't it?
Good troll for a non-political question. :-)

Luigi

We did pretty well with a 'summer dresses' thread-jack
once.........those were the days.
Summer dresses are wonderful... unless it's on that bitch Ann Coulter,
then anything looks like a pillowcase full of doorknobs.
And then there was Robin's butt (Hartl not Lee). The stuff of wet
dreams, that.
8-O

"Robatoy" wrote:

-----------------------------------------------------
We did pretty well with a 'summer dresses' thread-jack
once.........those were the days.
Summer dresses are wonderful... unless it's on that bitch Ann Coulter,
then anything looks like a pillowcase full of doorknobs.
---------------------------------------------------------

Look out, Palin's back.

So youl have another pillowcase full of doorknobs to join Coulter

Lew
..

On Jul 14, 11:59*am, jo4hn wrote:
Robatoy wrote:
On Jul 14, 2:17 am, Luigi Zanasi wrote:
On Jul 13, 11:37 pm, "Upscale" wrote:

"RonB" wrote in message
Holy Crap!
72 Posts on Plumber's Tape!!!!!!!!!!!!!!!
You guys are life-deficient.
But, but, but.... I got to dream of women draped out in Teflon tape.
That's a life isn't it?
Good troll for a non-political question. :-)

Luigi

We did pretty well with a 'summer dresses' thread-jack
once.........those were the days.
Summer dresses are wonderful... unless it's on that bitch Ann Coulter,
then anything looks like a pillowcase full of doorknobs.

And then there was Robin's butt (Hartl not Lee). *The stuff of wet
dreams, that.
* * * * 8-O

Last wet dream I had, I dreamt that there was a hole in the eaves-
trough , and that my window was open, and that the wind was blowing
rainwater into the bedroom...
..
..
..
..
I used to like wet dreams.

On Jul 14, 12:01*pm, "Lew Hodgett" wrote:
"Robatoy" wrote:

-----------------------------------------------------
We did pretty well with a 'summer dresses' thread-jack
once.........those were the days.
Summer dresses are wonderful... unless it's on that bitch Ann Coulter,
then anything looks like a pillowcase full of doorknobs.
---------------------------------------------------------

Look out, Palin's back.

So youl have another pillowcase full of doorknobs to join Coulter

Lew
.

On the humpability scale, Palin ranks quite a bit higher than that
scarecrow Coulter. Still not as high as Bebe Neuwirth though.