Rattle noise from pipes/unknown orange stuff on MM silver coupler (hot water tank)

[dieselgg]

I am replacing the copper tubing from the out port of my hot water tank. This also includes the silver male-male coupler ( threaded on either end). The threaded end that joins with copper pipe, I find some this orange stuff around the thread. It is either maybe orange teflon tape or orange anti-seize stuff. I can't tell what it is?

The reason i am replacing is that sometimes when we turn on the taps or faucets a noise is coming from the pipes. It does not sound like vibration but more like almost really tine pebble rattling through the pipes. The rep from the hot water tank noticed leaks coming from two elbows of the copper piping on the outport. He suggests removing the silver double threaded coupler all the way up to the elbow with the leak. He believes it is all corroded inside or something to that effect due to the leaks.

Any help would be appreciated.

[dieselgg]

I did some reading, I think the orange stuff is serving the purpose what pipe wrap tape would do. I think, but the orange stuff is not a vinyl tape material more like a coating. If that is what it, can I use teflon tape alone for the threads and/or do I have to use it conjunction with plumber's putty.

[plumbdog10]

What you call a "male-male coupler" would be commonly known as a "nipple".

Where did you get your engineering degree?

[dieselgg]

My background is electrical eng. How do you expect me to identify these parts and know the plumbing language ... that is why I ask. Maybe you assumed my background was mechanical eng or something similiar. I would not expect you to know your way around an electronics circuit board?

[plumbdog10]

My background is electrical eng. How do you expect me to identify these parts and know the plumbing language ... that is why I ask. Maybe you assumed my background was mechanical eng or something similiar. I would not expect you to know your way around an electronics circuit board?

Nipples are used by electricians. As are "couplings" not "couplers".

[PLUMBER RICK]

sounds like it's a "dielectric" coupling. it's used to separate the copper to galvanized connection. this would cause electrolysis.

i prefer a flex connector over a dielectric union or coupling.

rick.

[freddy]

Soung like your pipe stub out of the water heater may have heat traps.that help to block hot water in tank. they some times rattle a bit. I would remove the nipples from the water heater and replace with brass, Teflone tape around the threads. If the plumbing pipes are traveling up, say from a basement, pipe your own heat trap. :)

[Newman]

I think by "silver male-male coupler" he is referring to galvanized pipe nipples.
I recently installed an AO Smith water heater for my parents and I used brass nipples and S/S flex supply lines.