Advice to prevent fitting leaks (can you measure twice and cut once so to speak)

[zwell]

I am new to this work and wanted to get some advice on preventing fitting leaks. I just worked on installing a heat pump water heater at my friends house and have attached a picture so you can see the setup.

We were using a ProPress system and had dry fit everything before we pressed all the fittings. Wouldn't you know it, we turned the water on and a small leak developed at the brass fitting where the arrow is pointing in the picture. For the threaded brass fittings we used blue monster teflon tape and believe we had a really tight seal. Obviously, once we discovered the leak we had to take it apart which I am sure you can imagine was a pain.

I guess my question to you all is if there are any ways that you double check your work before turning everything on only to find a leak then? I know this is a really broad question that I am sure varies greatly based on the types of material and fittings being used, so I guess I am interested more specifically in any advice you all have based on the setup we were using here. Thanks.

 

[Jeff Handy]

From your pic, it looks like you used blue tape on some connections, white on another one, and nothing on the one by the arrow.

Some folks swear by using both dope and tape, belt and suspenders.

I usually just use white tape.

I probably over-tighten most connections, but have never cracked anything.

I use teflon dope on galvanized fittings that are older and rusty, it seems to help them screw in tighter than tape.

 

[zwell]

From your pic, it looks like you used blue tape on some connections, white on another one, and nothing on the one by the arrow.

Some folks swear by using both dope and tape, belt and suspenders.

I usually just use white tape.

I probably over-tighten most connections, but have never cracked anything.

I use teflon dope on galvanized fittings that are older and rusty, it seems to help them screw in tighter than tape.

Thanks Jeff. I was wondering if using teflon tape and pipe dope helped reduce the risk of a leak or was just overkill, especially for brand new brass fittings. We did use blue tape by the fitting with the arrow, but must have threaded past the tape.

 

[Jeff Handy]

Meanwhile, that is the only connection that leaked.

So maybe the amount of tape applied was skimpy.

Or it might have been wound backwards, which results in a poor seal because the tape gets pushed out of the threads.

 

[zwell]

Meanwhile, that is the only connection that leaked.

So maybe the amount of tape applied was skimpy.

Or it might have been wound backwards, which results in a poor seal because the tape gets pushed out of the threads.

Yeah, when we checked the connection it appeared we had a lot of tape and we did thread it counterclockwise. Clearly we didn't do something right and I am thinking we just weren't careful enough when we threaded it.

I am also wondering about the quality of the fittings we used. We just bought the basic brass fittings from Home Depot so not sure if there are quality issues with the fittings themselves?

 

[Jeff Handy]

Tape should be wound on clockwise, and firmly, so it is pulled down into the threads.

 

[zwell]

Tape should be wound on clockwise, and firmly, so it is pulled down into the threads.

Oh, my bad, that's what I meant Jeff and wrapped about 3 times up to the last thread. Appreciate the clarification.

 

[breplum]

I really recommend flex connectors on water heaters.
When installing expansion tank, we create a branch that includes a shutoff valve and a tee with a hose bibb so that when (they always fail) you have to change the tank, you can isolate and depressurize.
As far as your leak, certainly there ought not be any reason that joint leaked except for Murphy's sixteenth corollary. Three wraps of good teflon like you used should definitely have worked.
We sometimes add a dash of joint compound on top, just for good luck. I've not had a threaded joint leak in decades unless a fitting cracked.
Clockwise is the direction for wrapping Teflon. The torn end of the tape should flow with the direction of the fitting to be attached.

 

[zwell]

I really recommend flex connectors on water heaters.
When installing expansion tank, we create a branch that includes a shutoff valve and a tee with a hose bibb so that when (they always fail) you have to change the tank, you can isolate and depressurize.
As far as your leak, certainly there ought not be any reason that joint leaked except for Murphy's sixteenth corollary. Three wraps of good teflon like you used should definitely have worked.
We sometimes add a dash of joint compound on top, just for good luck. I've not had a threaded joint leak in decades unless a fitting cracked.
Clockwise is the direction for wrapping Teflon. The torn end of the tape should flow with the direction of the fitting to be attached.

As always, thanks breplum. Do you have specific flex connectors, shutoff valve or hose bibbs that you recommend?

 

[breplum]

I haven't had any reason to be picky about corrugated stainless steel water heater flex, though I have seen some with pretty poor i.d. on the corrugations. Supply houses around here carry Arrowhead mostly but again, not had any issues arise that would steer me towards one special brand.

 

[Mitchell-DIY-Guy]

Tape should be wound on clockwise, and firmly, so it is pulled down into the threads.

Yeah what he said.

I once owned a car wash, with more plumbing in one location than most plumbers see in a month. Everything from 2" copper mains, RPZ, boilers, threaded black gas lines, copper, pex, stainless down to the itty-bitty .25" poly lines, and every fitting imaginable. A day without some kind of leak or failure (literally, MILES of tubing) was a blessing. I learned from the best who helped me and taught me the servicing tricks. One by one over the years, changed most fittings from brass to stainless (car wash soap eats brass) and most of the poly fittings from compression to push.

GOOD PTFE tape. We used LACO when we could find it. Not too thick but not too thin. We used .25" on small fittings, and the standard .5" on larger. Always a little bit of some kind of thread sealant, we used not a "dope" per se but Loctite 567. Always make the fitting very tight.

 

[Helper Dave]

It can be a much easier job with press, like you used. Not sure what order you did it in, but if you tighten the threaded connections first, you can get the whole thing on the pipe and level it up without worrying about the classic dilemma, "It's level, but can I go around once more, or not?"

Real easy to get it all tight when there's nothing else to consider.