Flowserve V-370 R3 Edward Valves - Manual (Page 8)

EDWARD UNIVALVE USER INSTRUCTIONS ENGLISH 12-13
8
GRINDING A WELD
(For canopy seal Univalves) stainless steel valves
Open valve to backseat. Using a standard grinding wheel,
remove the weld by grinding from the top of the body face
and bonnet outside diameter (see photo). Continue this
process around the valve until all weld is removed where
the body and bonnet are joined together. Clean the valve
with a wire brush. A penetrating oil may be used where
permissible to loosen the threads joining the body and
bonnet.
SCARFING A WELD
(For fillet-welded Univalves) carbon steel and low alloy
valves
1. Air-arc method Open valve to backseat.
Using air-arc equipment, make a series of cuts in the
valve weld (see photo and sketch). Continue making
cuts until the valve weld takes on a grooved scarfed-
out appearance. Clean the valve with a wire brush.
A penetrating oil may be used where permissible to
loosen the threads joining the body and bonnet.
2. Oxyacetylene method Open valve to backseat. Using
an oxyacetylene torch equipped with a scarfing tip,
make a series of cuts in the weld until it takes on a
scarfed-out, grooved appearance. Clean the valve with
a wire brush. A penetrating oil may be used where
permissible to loosen threads joining the body and
bonnet.
ALTERNATE WELD-CUTTING METHODS FOR UNIVALVES
Line pressure must be relieved before making any
repairs.
This sketch shows the sequence of cuts necessary to remove the fillet weld by both
oxyacetylene and air-arc methods. Place scarfing torch or welding electrode tangent
to the bonnet, as indicated in position A. When metal reaches cutting temperature,
start blowing oxygen or air while moving torch backward. Weld metal should be
blown away. Move torch counterclockwise to position B. Repeat until entire fillet
weld is removed and gap is continuous. DO NOT REMOVE EXCESS MATERIAL
FROM BONNET OR UPPER BODY FACE. A
B