Overtighten Threads?

[Old Man James]

Yesterday we had to replace a gate valve and we could NOT unscrew the base from the copper pipe riser; nor could we unscrew the reducer on the other side of the valve from the valve body. They were both connected many years ago and were wrapped with Teflon. We still haven't gotten them apart and are considering just cutting them off and tossing them; starting all over. And before anybody asks, yes we used pipe extenders and had a good grip on the bodies. Along with two gargantuan fellows on each side - nothing.
Can you overtighten pipe threads??? If so, what is the rule 'of thumb' for tightening? One turn (with wrench) past solid 'hand tighten' Half turn? Did the Teflon possibly seize up? I'm NOT exaggerating, we could not break those joins apart.
Any help or thoughts would be appreciated; perhaps someone has some past history of this happening to them, also?

 

[Jeff Handy]

What about hitting the parts with a torch or heat gun for awhile, just not long enough to soften any nearby sweated joints.

I never was taught any rule about proper tightening or torque pounds whatever, just experience that gave me a feel for what would leak, or what would bust a pipe or fitting.

 

[Twowaxhack]

I find a lot of over tightened joints on a regular basis.

Especially gas lines connected to water heaters......way too tight.

 

[Old Man James]

What about hitting the parts with a torch or heat gun for awhile, just not long enough to soften any nearby sweated joints.

I never was taught any rule about proper tightening or torque pounds whatever, just experience that gave me a feel for what would leak, or what would bust a pipe or fitting.

I though about that but was concerned that the copper riser pipe would expand faster than the brass valve attached and only tighten the joint more so we didn't.

 

[Jeff Handy]

Heating still might break loose the stuck threads, then you can try wrenches again after things have partially cooled down.
The copper pipe will cool faster than the big heavy brass valve body or fittings.

 

[Twowaxhack]

Usually things assembled with tef tape come apart pretty easy.

 

[Old Man James]

Heating still might break loose the stuck threads, then you can try wrenches again after things have partially cooled down.
The copper pipe will cool faster than the big heavy brass valve body or fittings.

Hmmm - sounds like something to try; I'll let you know.

 

[Old Man James]

HEATING WORKED!!!!!! I have a small acetylene torch and we went out today to try one more time to loosen those valves. After rigging opposing wrenches to twist the valve without turning the copper riser pipe, we applied heating all around the big brass valve. After about 4-5 minutes, pressure was applied to the wrenches and (LO!) the valve began to turn!!! Keeping the hear applied until the valve had turned a couple rounds; then removed heat and turned the valve all the way off. I'm amazed that it worked; all 8 other valves responded the same way (about the same amount of time - one was a little stickier but it finally let go). At first, I wasn't going to try then thought "if it works, it will save a TON of time; if it doesn't all you've lost a little time today". Thankfully, the very first one let go; I wasn't going to try more than one.

Many thanks to Jeff Handy for the thought (file this one away for someone else).

This has proved to be the 'excellent site' for DIY plumbers (and all).

P.S. Examined the threads, could not see a reason for the 'seizing'; Teflon was still wrapped but where the solid join was, there was no teflon - like it had, literally, been squeezed out. (?)

 

[Jeff Handy]

Hurray!

 

[Jeff Handy]

Once in a while, my long-winded blathering actually pays off, haha!

 

[Twowaxhack]

HEATING WORKED!!!!!! I have a small acetylene torch and we went out today to try one more time to loosen those valves. After rigging opposing wrenches to twist the valve without turning the copper riser pipe, we applied heating all around the big brass valve. After about 4-5 minutes, pressure was applied to the wrenches and (LO!) the valve began to turn!!! Keeping the hear applied until the valve had turned a couple rounds; then removed heat and turned the valve all the way off. I'm amazed that it worked; all 8 other valves responded the same way (about the same amount of time - one was a little stickier but it finally let go). At first, I wasn't going to try then thought "if it works, it will save a TON of time; if it doesn't all you've lost a little time today". Thankfully, the very first one let go; I wasn't going to try more than one.

Many thanks to Jeff Handy for the thought (file this one away for someone else).

This has proved to be the 'excellent site' for DIY plumbers (and all).

P.S. Examined the threads, could not see a reason for the 'seizing'; Teflon was still wrapped but where the solid join was, there was no teflon - like it had, literally, been squeezed out. (?)

They probably put the Teflon on backwards. Then they had leaks to they cranked it all down gorilla tight.

 

[Old Man James]

They probably put the Teflon on backwards. Then they had leaks to they cranked it all down gorilla tight.

No, we checked for backward wrapping and what was left unwound correctly.

 

[Twowaxhack]

No, we checked for backward wrapping and what was left unwound correctly.

Simply over tightened then. Thanks for the feedback

 

[skeezix]

Once in a while, my long-winded blathering actually pays off, haha!

Blather away! Every one of your posts is written in a down-to-earth, matter-of-fact way and that always contain useful tips and info that has helped me out of some jams!!