At work we had to fix a buried 3" copper water line, what is the best way to do it brazing or solder?

Quote:

---

Originally Posted by jeff807

At work we had to fix a buried 3" copper water line, what is the best way to do it brazing or solder ??

---

Hello Jeff !
The main difference between brazing and soldering is the temperature to which the joint is heated when connecting. I doubt however if that difference has much effect on the quality of the joint if the pipe is buried or not. A higher temperature may at least ease the actual joining (in view of the temperature loss to the surrounding area.
You ask for "the best way", but that depends a lot on the actual situation and the materials used. However your question is rather short on the required details...
;)

You need to address the following variables: temperature, pressure and corrosion.

Jeff:

I don't think either way is allowed for underground copper pipe. I am 100% sure SOLDERING anything underground is illegal... can't really see why brazing would be any different. Call the local plumbing inspector in your area and ask him what is permissible.

Most likely, You need to purchase a 3" copper COMPRESSION TYPE repair coupling. Not cheap, not possible to find at any local home supply, for sure.

If needed, contact a local plumbing supply house and see what they can do for you. Most likely you will need to find a company that specializes in supply parts for water mains.

Let us know what you find... thanks... Mark

.

Quote:

---

I am 100% sure SOLDERING anything underground is illegal

---

Bang on Mark! We rough our slabs with type "L" soft copper and bring then up out of the ground in the walls to manifolds to connect them. The one time we roughed a town house with underground joints the inspecter made up pump up to 125 PSI and hold it overnight. However in our area for a underground leak, it's admissible to cut the bad piece out and solder in a replacement. HVAC guys braze their copper joints, plumbers solder. Good luck, Tom

Quote:

---

Originally Posted by jeff807

At work we had to fix a buried 3" copper water line, what is the best way to do it brazing or solder ??

---

It depends on where you are located, which code prevails in your area and what type of ground cover will be used.

A number of municipalities, including most of the West Coast will allow the use of 95/5 solder for burial if it is easily accessible in the future -- If it's to be buried under concrete, then silver bearing brazing rods are required.

Your best bet is to find out what the local authority allows for your particular scenario.

If soldering is allowed, then I would choose this option over brazing -- The high heat required to braze copper, particularly hard drawn copper, can leave the pipe brittle and susceptible to damage from material used as backfill.

If your local authority requires brazing, then buy several bags of sand to use as backfill over the top and bottom of the brazed fittings.