NIBCO Technical Services • Phone: 1.888.446.4226 • Fax: 1.888.336.4226
9
Appendix - General Installation Recommendations
SOLDERING
1. Cut tube end square. Ream, deburr, and check for dry fit. Do not use tubing that is out of round
or fits so tightly into the solder cup that it must be forced or hammered into place.
2. Prior to preparing a solder cup on a valve:
Open a ball valve fully, to avoid damaging the ball
Close a gate or globe valve fully, to avoid getting sanding fines in the seat well or damaging
the sealing surfaces
Remove the hanger assembly on a swing check valve, especially on soft seal discs such
as Buna-N or PTFE discs.
Use sand cloth or a steel wire brush to clean both ends to a bright metal finish. Steel wool is not
recommended. Apply flux immediately upon cleaning surfaces of joints to be soldered. If fluxed
parts are allowed to stand, the water in the flux will evaporate, and dried flux is liable to flake off,
exposing metal surfaces to oxidation.
3. Apply flux to outside of tube and inside of solder cup. Surfaces to be joined must be completely
covered. Use flux sparingly.
4. Assemble joint by inserting tube into socket hard against the stop. The assembly should be
firmly supported so that it will remain in alignment during the soldering operation.
Prior to soldering:
Close a ball valve to trap the seats against the surface of the ball.
Open fully a gate or globe valve, to prevent soldering the closure member to the seats.
Remove the hanger assembly on a swing check valve.
Take care to not overheat a spring-loaded check valve.
o On leaded-alloy bronze spring-check valves, wrap the body in a wet rag
NOTE: On one-inch and larger valves, it is difficult to bring the whole joint up to temperature at
one time. It will frequently be found desirable to use a double-tip torch to maintain the proper
temperature over the larger area. A mild pre-heating of the whole socket area is recommended.
Apply heat to tube first. Transfer as much heat as possible through tube into valve. Avoid
prolonged heating of valve itself. Never direct the flame into the capillary gap between the tube
and solder cup – always work the flame away from the gap. Evenly apply the flame across the
joint, from base of the cup to a inch past the tubing, sweeping the entire circumference of the cup
and tube in continuous motion and not dwelling on any one point.
When flux appears liquid and transparent, start sweeping flame back and forth along axis of joint
to maintain heat on parts to be joined, especially toward base of valve socket, while feeding solder
into the capillary gap.
5. Use just enough solder: with wire solder, use 3/4" for a 3/4" valve, etc. If too much solder is
used, it may flow past tube stop and clog sealing area. When the joint is filled, a continuous run
of solder alloy will be visible and drip from the bottom of the joint.
To Next Page
Loading...
Need help?
General
