Will small leaks in brass fittings eventually stop?
#1
Member
Thread Starter
Will small leaks in brass fittings eventually stop?
I just installed my water heater and expansion tank using a brass tee, nipples, and 90. I put teflon tape on the threads and cranked down as hard as I could so the tee and 90 line up and right when I fired it up, there are just some small drops coming from the connections. Do those normally stop after a little bit or do I need to tear that apart and make it tighter or use something else to seal? I literally just finished this about a half hour ago so I will see what is going on in the morning.

#2
The one and only "small water leak" that I occasionally have that stops is the o-ring seal on my whole house water filter,
A leaking pipe needs to be repaired, Id suggest teflon pipe dope vs teflon tape!
A leaking pipe needs to be repaired, Id suggest teflon pipe dope vs teflon tape!
#3
Member
Thread Starter
Ok, I'll take it apart tomorrow and reassemble. What exactly is Teflon pipe dope? Is there a particular brand of it or will it just say Teflon pipe dope on it? Would you put tape first then dope?
#4
Member
Adding pipe thread sealant over the teflon tape will stop the leak. However this will require disassembly. Also the silver pipe at the top of the tee appears to be a compression seal and not a pipe thread. Is there a sealing washer inside the silver nut and are its threads compatible with the NPT (national pipe thread) threads of the NPT coupler? I also suggest supporting the expansion tank from above because the pipe threads below should not be used to support the added weight when it fills with water. Also, is the silver pipe flexible enough that it isn't putting a strain on the connection with the tee?
#5
It's just standard sealing dope, available everywhere.
They are interchangeable, but I find more leaks with tape than dope!
They are interchangeable, but I find more leaks with tape than dope!
#6
Group Moderator
This is why I hate NPT fittings when dealing with T's and 90's. The point where it is tight and not leaking often is not where the fitting needs to be pointing. Sometimes you can get away with more wraps of Teflon tape or by switching to pipe dope. Unfortunately the most reliable way I've found is to tighten the snot out of it. Often this requires bigger wrenches and pulling a muscle. Every plumber has a pair of really big pipe wrenches with names like "Big Bertha" and "Ox" that don't get used very often but sometimes monster sized wrenches are needed.
Once in a while I just get different fittings and try again. NPT fittings are tapered. They get tighter the more you tighten them and how well the fittings mate together depends on the manufacturer's equipment. While this is generally a negative it can sometimes work in your favor as getting different parts can make fittings get tight at different rotational positions.
Once in a while I just get different fittings and try again. NPT fittings are tapered. They get tighter the more you tighten them and how well the fittings mate together depends on the manufacturer's equipment. While this is generally a negative it can sometimes work in your favor as getting different parts can make fittings get tight at different rotational positions.
#7
Member
Thread Starter
Ok, I'll just disassemble, put tape and dope, and crank it down. I have a pretty big pipe wrench somewhere around here. So I guess you can't overtighen them then?
As far as the silver flex line, it does have a washer and it is not leaking at that connection. There is now pressure on it with that bend (is it OK to have it bent like that because that is the shortest length I could find?). I don't like the tee supporting the weight of the tank either which is why I have those blocks under it to take the weight off of the tee.
As far as the silver flex line, it does have a washer and it is not leaking at that connection. There is now pressure on it with that bend (is it OK to have it bent like that because that is the shortest length I could find?). I don't like the tee supporting the weight of the tank either which is why I have those blocks under it to take the weight off of the tee.
#8
is it OK to have it bent like that
#9
Member
One supplemental thought-
If you are on a private well, and have hard water, then YES, small leaks will be self-sealing.
I happen to be on a ridge of hard shale, the local water isn't just "hard" (high Ca++ and Mg++)
but it is actually high in "rare earth elements" (various odd minerals).
In my situation, dripping pipe generally self-seal in about 4 months.
If you are on a private well, and have hard water, then YES, small leaks will be self-sealing.
I happen to be on a ridge of hard shale, the local water isn't just "hard" (high Ca++ and Mg++)
but it is actually high in "rare earth elements" (various odd minerals).
In my situation, dripping pipe generally self-seal in about 4 months.
#10
Member
Thread Starter
Just be aware that any kind of corrugated pipe like that has a huge impact on flow, they are very restrictive compared to a smooth pipe, doesn't mean it's bad but the cost of convenience

#11
Group Moderator
Some earthquake prone areas require the use of flexible connections so the water heater can move during an earthquake without breaking a water line.
#12
Member
Thread Starter
Just thought I would report back. I took it apart, put pipe dope on everything, and cranked it down hard. No leaks!
#13
Group Moderator
#14
Forum Topic Moderator
Plumbing can sometimes be frustrating


Zorfdt
voted this post useful.