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ES-A-ACV-LF920GD 2115
© 2021 Watts
Pressure Relief, Sustaining or Backpressure Control Valve
Full Port Ductile Iron Single Chamber Valve
Features
• Opens when upstream pressure is above setpoint
• Closes when upstream pressure is below setpoint
• Adjustable Closing Speed
• When installed on branch of tee, acts as Pressure Relief Valve
• When installed between two pressure zones, acts as Pressure
Sustaining Valve
• When installed on discharge of a pump, acts as Backpressure
Control Valve
• Setpoint is adjustable
Options and Accessories
{
FC – Flo-Clean Strainer (Standard 1¼" – 4")
{
Y – Y-Strainer (Replaces Flo-Clean)
{
AOS – Adjustable Opening Speed (Standard 1¼" – 4")
{
P – Position Indicator
{
L – Limit Switch
Standard Components
1
X
X
X
Y/FC
3
2
(AOS)
CLOSES VALVE
OPENS VALVE
FLOW
P/L
1 – Main Valve (905GD - Single Chamber)
2 – Relief / Sustaining Control
3 – Adjustable Closing Speed
X – Isolation Cocks
LEAD FREE
*
The information contained herein is not intended to replace the full
product installation and safety information available or the experi-
ence of a trained product installer. You are required to thoroughly
read all installation instructions and product safety information
before beginning the installation of this product.
NOTICE
* The wetted surface of this product contacted by consumable water
contains less than 0.25% of lead by weight.
Operation
The Pressure Relief, Sustaining or Backpressure Automatic Control
Valve (ACV) is designed to permit flow when upstream pressure
is above the adjustable setpoint of the control pilot, and throttle
toward closed when upstream pressure falls below the adjustable
setpoint. It is controlled by a normally closed control pilot designed
to: 1) Open (allowing fluid out of the main valve cover chamber)
when upstream pressure is above the adjustable setpoint, and,
2) Close (allowing fluid to fill the main valve cover chamber) when
upstream pressure is below the adjustable setpoint. An increase in
upstream pressure causes the valve to modulate toward an open
position. A decrease in upstream pressure causes the valve to
modulate toward a closed position.
When the valve is installed "off the main line" on the branch of a
tee, it serves as a Pressure Relief Control Valve. The valve is nor-
mally closed, and quickly opens when upstream pressure exceeds
the pilot setting, relieving pressure, commonly discharging to a
storage reservoir, pump suction, or atmosphere. When upstream
pressure is lowered below the pilot setting, the valve closes at a
controlled, adjustable rate.
When the valve is located "in line" connecting two distribution
zones, the valve acts as a Pressure Sustaining Control Valve.
When pressure in the upstream zone falls below the pilot setting,
the valve modulates toward a closed position, sustaining pres-
sure in the upstream zone. The valve will close, if necessary, until
upstream pressure is above the pilot setting. The valve should be
specified to include the optional opening speed control and posi-
tion indicator when used for Pressure Sustaining applications.
When the valve is installed "in line" on the discharge of a pump, it
acts as Backpressure Control Valve. When pump discharge pres-
sure falls below the pilot setting, the valve modulates toward a
closed position, increasing backpressure against the pump. The
valve should be specified to include the optional opening speed
control when used for Backpressure applications.
Series LF920GD
