What's a "Mormon" coupling (used for)?

[dtn6770]

I Googled it and got completely different subject matter.

In any case, the term is (probably) slang for a piping/hose fittings used in the automotive and/or industrial engine industry.

Anyone have a clue the purpose they serve or any history on the naming?

Thanks in advance.

 

[JohnBreen]

Hi dtn6770,

If I were old enough to remember I might mention to you that the old Marmon automobile had a fluid coupling that connected the engine to the transmission. Try Googling that or try one of the antique automobile discussion boards.

Regards, John

 

[FACS]

Marmon Clampband: A metal band wrapped around two cylinders to hold them together.

Mormon coupling: No such thing in "McGraw-Hill Dictionary of Scientific and Technical Terms."

Charlie

http://www.facsco.com

 

[JohnBreen]

Wiki comes through:

en.wikipedia.org/wiki/Marman_clamp

A Marman clamp is a type of heavy-duty band clamp: this allows two flat cylindrical interfaces to be simply clamped together with a ring clamp. Also sometimes known as a "Marman ring".

A common use for Marman clamps is their use as a quick-disconnect connector in wide-diameter fuel lines. Another example is their use in space vehicles, for example on the Cassini Plasma Spectrometer on the Cassini orbiter.

The Marman clamp was invented by Herbert Marx, better known by his stage name of Zeppo Marx as one of the Marx Brothers. It was manufactured by his company Marman Products. At the time it was designed to secure cargo during transport. The U.S. Military used it to transport the atomic bombs used at the end of the Second World War.

Marman clamps are found in many modern moving vehicles, though the screw band type clamp is becoming more popular.

The name is often incorrectly spelled "Marmon".

 

[crjones]

The marmon coupling is now part of the Aeroquip product line. It is used to soft couple two pieces of pipe without special preparations. Generally they worked well to 165 pisg of line pressure.

 

[monkeydog]

Marman Clamps are a stress engineer's nightmare.
A very simple and effective design, just tough to analyze.

 

[MikeHalloran]

Aeroquip, Voss, and other manufacturers supply them, not just as the hose clamp shown in the Wiki, but also in the v-band variant:

http://www.hosenow.com/qukcpl.htm

... not all with the quick- disconnect on the t-bolt as shown.

There are a couple of MSxxxxx numbers for them, and commercial variants. Custom versions are not terribly more expensive than standard parts.

They are often used to attach expansion bellows to marine turbocharger exhausts, and in marine exhaust, at both ends of metallic bellows. I understand they are also popular in aircraft because of their light weight and low bulk.

The applicable Aeroquip catalog shows several ways to couple tubes with them, most of which involve flanging the tube or welding on a beveled adapter.

They only _look_ simple. You have to use sealant, align the flanges perfectly, tap the clamp into position with a mallet after snugging the t-bolt, and torque the t-bolt, typically to 55 _inch_-lbs. More torque doesn't make the flanges stop leaking, it only turns the clamp into junk.



Mike Halloran
Pembroke Pines, FL, USA

 

[dtn6770]

I neglected to mention that we use them in cooling water services associated with industrial engines.

Anyway, I did some more digging and found that we apparently use Flexmasters Joints (for rigid pipe) [NH1600s] and our term “Mormon” is just local slang and probably a variation originating from the earlier mentioned “Marmon” or “Marman” couplings/joints.

Thanks for the dialog.

 

[MikeHalloran]

Ah. That's a horse of another color. The Aeroquip Flexmaster is roughly equivalent to the Straub Flex coupling.

They use a flared sleeve that looks like it might mate with marman v-band couplings, though I don't think they'd fit right, and a couple of rubber gaskets having an inverted V cross section. The gaskets may or may not have internal metal teeth to grip a plain pipe.

It's grossly incorrect to call them Marman couplings.




Mike Halloran
Pembroke Pines, FL, USA

 

[dtn6770]

Many slang terms aren't correct (bad=good, sic[k]=...not-ill, etc.).

Might be why it's a Mormon coupling here. It's an established term (30 years +/-) that is used verbally and on the stock shelf so I'm not about to redirect it's momentum. All bills of materials and inventory systems refer to them as "couplings" with the respective part numbers so I'm not concerned about anyone getting the wrong impression.