Buying Guide

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Revised 7/20/2018
Valve Installation Tips
SOLDERING AND SILVER BRAZING
Analyze the application to determine which valve is best suited for
installations, keeping in mind the service for which the valve is recom-
mended. Before installing the correct valve, review the installation
instructions to prevent damage to the valve and to assure its maximum
efficiency.
1. Cut tube end square. Ream, burr and size.
2. Use sand cloth or steel wire brush to clean both ends to a bright
metal finish. Steel wool is not recommended.
3. Apply flux to outside of tube and inside of solder cup. Surfaces to be
joined must be completely covered. Use flux sparingly.
4. Be sure that valve is fully open. Apply heat to tube first. Transfer
as much heat as possible through tube into valve. Avoid prolonged
heating of valve itself.
4a. Silver Brazing Method: Assemble parts to be brazed. 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.
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 brazing operation.
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 desir-
able 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 parts to be joined. The preferred
method is by oxy-acetylene flame. Heat tube first, beginning one
inch from edge of valve. Sweep flame around tube in short strokes
up and down at right angles to run of tube. To avoid burning through
tube, the flame should be in continuous motion and not allowed to
remain on any one point.
Apply flame to valve at base of socket. Heat uniformly, sweeping
flame from valve to tube until flux on valve becomes quiet. Avoid
excessive heating of valve.
When flux appears liquid and transparent on both tube and valve,
start sweeping flame back and forth along axis of joint to maintain
heat on parts to be joined, especially toward base of valve socket.
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 joint is filled, a continuous run of solder or braz-
ing alloy will be visible.
5a. Silver Brazing Method: Apply brazing wire or rod at point where
tube enters valve socket. Keep flame away from rod or wire as it is
fed into the joint. Move flame back and forth as alloy is drawn into
joint. When the proper temperature is reached alloy will flow readily
into space between tube outer wall and valve socket. When joint is
filled, a continuous rim of brazing alloy will be visible.
6. Remove excess solder with small brush while plastic, leaving a fillet
around end of valve as it cools.
SILVER BRAZING
The strength of a brazed joint does not vary appreciably with the dif-
ferent brazing materials, but depends to a large extent upon the main-
tenance of proper clearance between the outside of the tube and the
valve socket. The interior dimensions of silver brazing valve sockets are
machined to the closest tolerances and finished smooth to promote full
capillary attraction.
NOTE: Care should be observed in cleaning and in removing residues of
the cleaning medium. Attempting to braze a contaminated or improperly
cleaned surface will result in an unsatisfactory joint. Silver brazing alloys
will not flow over or bond to oxides. Oily or greasy surfaces repel fluxes,
leaving bare spots which oxidize and result in voids and inclusions.
THREADING
Grit, dirt or any foreign matter accumulated in the pipe can hinder effi-
cient valve operation and seriously damage vital valve parts. Thoroughly
clean pipe internally with air or steam.
When threading pipe, gauge pipe threads for size and length to avoid
jamming pipe against seat and disc. Thoroughly clean threaded end to
remove any harmful steel or iron deposits. For a good joint, use PTFE
tape or pipe dope. If pipe dope is used, apply sparingly on pipe threads,
never on valve threads. Do not allow any pipe dope into valve body in
order to avoid damage to disc and seat.
Before installation, check line of flow through valve so that valve will
function properly. Close valve completely before installation. Apply
wrench to hex next to pipe and guard against possible distortion. After
installation of valve, support line; a sagging pipe line can distort valve
and cause failure.
FLANGED
There are several steps to follow to make sure that a flanged joint will
be properly assembled. First, clean the joint carefully. Then loosely
assemble the joint by putting in the bottom two or three bolts. Then
carefully insert the gasket into place. The bottom bolts will help locate
the gasket and hold it in position. Then insert the rest of the bolts into
place and tighten all of the bolts evenly—not in rotation, but by the
cross-over method to load the bolts evenly and eliminate concentrated
stresses. The bolts should be checked for tightness after an appropriate
interval of use and retightened if necessary.