On 07/27/06 12:40 pm firstname.lastname@example.org wrote:
I remember that when I was perhaps 8 or 9 years old I heard the plumber
who was working in our house refer to an "M and F" coupling. I asked
what this stood for, and he told me that it was short for "Male and
Female." When I asked why, he told me that I would understand when I was
On Thu, 27 Jul 2006 13:41:19 -0400, "Percival P. Cassidy"
Do you understand yet?
I still dont understand because I have NEVER seen a pipe with either a
penis or a vagina. Have you? <lol>
(I did see several pipes that had nipples though, so I instantly knew
they were female) !!!!!!!!!!!! :)
You can't. They're the same.
"MPT" means "male pipe thread". "FPT" means "female pipe thread".
"NPT" ("national pipe thread") is simply a generic term for
that same pipe thread, male or female.
In other words, "MPT" and "male NPT" means the same thing.
Similarly, MIP (male iron pipe) == MPT and FIP (female iron pipe) == FPT.
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
No, the "T" stands for "tapered", not "thread". As in NPS for straight
threads, etc. The designations "NPT", NPS, etc., are part of the national
standards (ANSI/ASME B1.20.1-1983 (R1992) etc).
"MPT" and "FPT" are bastardizations not in the standards. Likewise "FIP"
and "MIP": common galvanized or black pipe is steel, not iron, and besides
the thread standards have nothing to do with iron vs steel vs brass, etc.
Just to confuse things. MPT is a subset of NPT. Because NPT can be MPT
or FPT. So, they aren't totally interchangable. Not to be a PIA, cause
a MPT would go nicely into a same size FPT, but can't guarantee that a
MPT would go into a NPT, only if it's a FPT NPT. If it were a MPT NPT,
that wouldn't work. So, if you have a NPT FPT on your SUV, you need a
MPT NPT, or you'll be SOL. KWIM? Then, you'll need a BFG, or BFH.
Christopher A. Young
You can\'t shout down a troll.
Okay thanks for your replies - but let me ask all of you this then
(this is the crux of the question):
I am trying to replace an air pressure gauge on a piece of equipment
(tire changer.) It has a male back mount. When I messure the diameter
of the threads I get more than 1/2" Is this considered 1/2" Male - NPT
? (It's more like 5/8") Or do I have some odd thing that is going to
cost me a fortune to replace. It doesn't appear to be tappered unless
it is "very" gradually tappered.
Pipe thread are sized to be on the OD of common pipe which is sized by the
Pipes nominal ID. Thus, 1/2" pipe is actually 0.840 inches in OD. 3/8"
pipe is 0.675 OD. So it would seem that you're looking at a 3/8 pipe
connection there if your 'more like 5/8"' observation is good. You can
check the pitch: 3/8NPT threads have 18 threads per inch, 1/2NPT has 14.
Easiest thing to do is to check it against some fittings of known size:
take it you local big box and screw some stuff from the plumbing aisle
onto it and see what fits.
Almost certanly not: if it's just a pressure gauge, you can even adapt it
to any old size and go from there.
The taper on NPT thread is about 1.75 degrees, about 3/4" in each foot,
it's easy to miss.
Remove the dead poet to e-mail, tho CC\'d posts are unwelcome.
Mean People Suck - It takes two deviations to get cool.
replying to Harry K, too much information dude wrote:
NPT is defined by ANSI/ASME standard B1.20.1.
Pipe threads are different from machine-screw and bolt threads. Those are
designated NC (national coarse) and NF (national fine.) The biggest difference
is the taper on pipe threads.
The taper rate for all NPT threads is 1 in 16 (3⁄4 inch per foot or 62.5
millimeters per meter) measured by the change of diameter (of the pipe thread)
over distance. The angle between the taper and the center axis of the pipe is
tan−1(1⁄32) = 1.7899° = 1° 47′ 24″.
Nominal Pipe Size (NPS) is loosely related to the inside diameter of Schedule 40
pipe. Because of the pipe wall thickness, the actual diameter of the threads is
larger than the NPS, considerably so for small NPS. Pipe of other schedules with
a certain NPS has different wall thickness, but the same outside diameter and
thread profile as Schedule 40, so the inside diameter of the pipe is therefore
different from the NPS.
Thread formNPTE and NPS threads have a 60° included angle and have a
Sellers thread form (flattened peaks and valleys).
NPTFA semi-compatible variant called National Pipe Taper Fuel (NPTF), also
called Dryseal American National Standard Taper Pipe Thread, defined by ANSI
B1.20.3, is designed to provide a more leak-free seal without the use of teflon
tape or other sealant compound. NPTF threads are the same basic shape but with
crest and root heights adjusted for an interference fit, eliminating the spiral
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