PDA

View Full Version : Compression Vs Sweating


ultrajoker
Apr 20, 2005, 04:05 AM
Hello all!

I need to replace a 1/2 dozen frozen valves in my basement that control water feeds up to 1st and 2nd floor bathrooms and kitchens. The current valves are sweat on. I am not that confident in sweating. Most of the lines are 1/2" one is 3/4". Can I remove these and replace with compression fit valves? What are the pros of sweating over compression fit? Thanks in advance.

labman
Apr 20, 2005, 07:38 AM
For the proficient, sweat is more quick and cheaper than compression. I am not sure you can find metal valves with compression fittings. You may have to use threaded adapters. If you go that route, I would strongly suggest ball valves. They leak less, faster to turn on and off, and you can tell at a glance if they are open or closed instead of guessing how much stem should be showing.

Metal to metal compression fittings may not seal well with old beat up pipe and left over solder.

With sweat fittings, you must dissemble the valve to avoid burning up any rubber or plastic parts. Ball valves are also available with sweat fittings.

Watch sizes. Pipe sizes are ID. Compression fittings marked 1/2'' may fit 3/8'' ID tubing.

There are plastic valves with compression fittings with rubber seals in them. Count on no leaks, but they can pull apart unless the pipes are rigidly held in place.

tommytman
Apr 20, 2005, 06:20 PM
Sweating isn't hard at all. Read about it in a plumbing book like the ones they sell at Lowe's. Then get a MAAP torch, flux, and lead free solder (MAAP is hotter than propane). Buy some copper pipe and fittings to prictice a bit. It's pretty easy once you try it a few times. I usually have the most trouble trying to get the water out of the lines before soldering.. . once you have done it you are set for life. Good luck. (make sure you don't heat the valves up too much when you solder or the valve material will melt... to get around this sometimes I use valves with pipe thread connections and use a pipe thread to sweat copper adapter. That way you can make up a 3-6 inch adapter that has a pipe thread on it to screw into the valve. Then when you solder it into the system it is pretty far away from the valve so the valve does not get hot)

Tom