Installation Instructions

Document No. 129-087
Installation Instructions
Rev. 2, October, 2000
Siemens Industry, Inc. Page 3 of 4
Installation, Continued
Normally closed Flowrite VF591SD,
VF591CD, and VF591ST valves
1. Loosen 3/8-inch square head set screw that
locks the 8-inch top actuator to the bonnet or
the 1-7/8 inch hex nut that locks the 12-inch top
actuator to the bonnet.
2. Loosen stem lock-nuts, 3/8-inch hex on 8-inch
top and 5/8-inch hex on 12-inch top. See
Figure 1.
3. Remove stem from stem extension in actuator
top. Then remove actuator from the bonnet.
4. For valve sizes 1/2-inch to 2-inch:
a. Loosen and remove cap at bottom of valve
body using a 1-3/8 inch hex wrench for 1/2-
inch valve, 1-9/16 inch hex for 3/4-inch
valve,
1-1/2 inch hex for 1-inch valve, 1-7/8 inch
hex for 1-1/4 inch valve, 1-3/4 inch hex for
1-1/2 inch valve, 1-5/8 inch hex for 2-inch
ST valve, and 2-1/8 inch hex for 2-inch SD
valve.
b. Pull stem and disc assembly out of the
bottom of valve body.
c. Hold disc holder firmly (in a vise if
possible). Then, using a 1/4-inch hex
wrench for 1/2-inch valve, 5/16-inch hex for
3/4-inch and 1-inch valves, and 1/2-inch
hex for 1-1/4 inch through 2-inch valves,
loosen the nut and remove it from the stem
to get access to the disc. See Figure 5.
Replace disc.
Figure 5. R.A. Assembly.
5. For valve sizes 2-1/2 inches through 6-inches:
a. Remove the four 3/4-inch hex cap screws
located on the bottom of the valve body and
remove the cap from the body. The gasket
between the bottom cap and the valve body
should be removed and replaced to assure
a tight seal when the valve is reassembled.
b. Pull stem and disc assembly out of the
bottom of the valve body.
c. A special throttling nut wrench is required to
loosen the throttling nut. This wrench can
be made as shown in Figure 7; it is not
available from the factory. Hold disc holder
firmly (in a vise if possible). Then, using the
special throttling nut wrench, loosen and
remove the throttling nut and disc. See
Figure 4. Assemble new disc and throttling
nut to stem. After tightening the throttling
nut, stake it (with a hammer, and punch in
four places) to stem assembly to prevent it
from becoming loose in service.
6. Reassemble valve in reverse order.
Water mix Flowrite VF591WM valves
1. Loosen the 3/8-inch square head set screw that
locks the 8-inch top actuator to the bonnet.
2. Loosen the 3/8-inch hex stem lock-nuts with a
wrench, see Figure 1.
3. Remove stem from stem extension in actuator
top. Then, remove actuator from the bonnet.
4. Loosen and remove bottom valve seat using a
1-7/16 inch hex wrench for 1/2-inch and 3/4-
inch valves, 1-3/4 inch hex for 1-inch valves, 2-
inch hex for 1-1/4 inch valves, 2-3/16 inch hex
for 1-1/2 inch valves, and 2-3/4 inch hex for
2-inch valves
5. Pull stem and disc assembly out of bottom of
valve body, see Figure 6.
Figure 6.