INSTALLATION INSTRUCTIONS
No. 4" 127W Pressure Regulator For Water
(Single Seat, Diaphragm, Spring Type)
No. 127W may be installed with diaphragm above or below the line.
IMPORTANT
When a reducing valve is used, it makes a closed system; therefore, a pressure relief valve must be installed in the down-
stream side of the regulator to protect equipment against excess pressure which is built up by the expansion of water from
the domestic hot water supply tank or heater.
ADJUSTMENT
TO ADJUST: When diaphragm is above the line, turn adjust-
ing collar from left to right to increase the reduced pressure
- opposite to decrease reduced pressure.
When diaphragm is below the horizontal line, turn adjusting
collar from right to left to increase the reduced pressure -
opposite to decrease the reduced pressure.
A steel rod is provided to turn adjusting collar.
Tighten packing nut lightly if leaks occur around stem. Re-
pack stem when light nut pressure cannot stop leak. Do not
tighten packing nut enough to bind stem. This causes un-
even regulation and excessive stem wear.
TO CLEAN: Inspect or replace worn valve disc, disconnect
control pipe and unscrew bonnet from valve body using blunt
tool and hammer on bonnet lugs. Lift entire topwork clear
of body.
IS-127W
1. Before installing, be sure pipe ends are reamed and threads
are cut to size. Blow out lines to remove all loose scale and
other foreign matter that can damage valve seat.
2. Install regulator in the line with the arrow on the body point-
ing in the direction of flow.
3. Connect
1
⁄
4
" or
3
⁄
8
" equalizer pipe as shown from the dia-
phragm chamber to a point in the reduced pressure line
or to the special tapping provided in the low pressure side
of the regulator body. This tapping gives you a convenient,
economical means of attaching the equalizer line, facilitat-
ing installation and eliminating fittings.
4. Install a needle valve in the control line. If uneven pres-
sure should cause the regulator to pulsate, its action can
be stabilized by throttling the valve.
NOTE: 15" diameter chambers are standardly furnished with
a pressure relief valve, factory set at 60 psi to protect the
chamber from excessive pressure. A drain line should be
attached to the relief valve to channel any potential discharge
to a safe place of disposal.
High Pressure
Reduced
Pressure
*
3
⁄
4
" size No. 223
regulator to handle low
demands. Set 10 psi
higher than 127W.
4" 127W
Needle Valve
No. 4" 127W Recommended Installation
Installed in tandem with smaller size regulator to
improve system performance and extend valve life.
*This auxiliary installation provides greatest maintenance
serviceability and better regulation for installations where
extreme low demand periods are frequent. The smaller size
regulator effectively serves low volume demands.
