Do lead-free forged-brass quarter-turn ball valves need to be disassembled before soldering? Anything inside that can be harmed by the heat of the torch?

  • Can wrapping a wet cloth around the center of the valve prevent heat damage to the seals, or would this prevent the formation of a good solder joint? Sep 30, 2021 at 17:42

2 Answers 2


I have to believe they could be harmed by excessive heat but it's also not customary to disassemble them before soldering.

The main thing is to use good technique, which in this case means to use the flame to heat the pipe only, not the fitting. Heat will conduct through the pipe into the fitting's socket -- exactly where the heat is needed. If you prep the surfaces (clean well; apply enough flux), heat the pipe, and apply solder and remove heat as early as possible it'll turn out fine.

  • I just saw a video on Youtube where the plumber (a pro) said he had been having leaks with this type of ball valve until he changed technique and began heating the pipe not the fitting, just as you have advised. Though in the video he does heat the fitting somewhat, and advises to angle the flame towards the pipe.
    – mr blint
    Oct 2, 2021 at 12:29

They will contain some kind of elastomeric seals like rubber O rings that could be deteriorated by heat. It depends on the type of rubber and the temperature at the elastomer. Temperature will depend on solder technique and size. The simplest answer is to remove elastomers during soldering.

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