2
ES-A-ACV-LF984GD 2115
© 2021 Watts
Pump Control Valve with Rate-of-Flow Feature
Full Port Ductile Iron Single Chamber Valve
Features
• Opens at adjustable rate on pump start-up
• Closes at adjustable rate on pump shut-off
• Limit Switch turns pump off when valve closes
• Throttles to maintain constant Rate-of-Flow
• Orifice Plate Assembly is remote mounted (field installed)
• Hydraulic Check Feature prevents flow reversal
• Solenoid equipped with Manual Operator
• Rate-of-Flow setpoint is adjustable
1
X
X
Y/FC
2
9
4
7
6
X
X
5
5
CLOSES VALVE
OPENS VALVE
FLOW
3(L)
8
Operation
Standard Components
Options and Accessories
{
FC – Flo-Clean Strainer
{
L – Dual Limit Switch
1 – Main Valve (905GD - Single Chamber)
2 – Model 22 Accelerator Control
3 – Limit Switch
4 – 3-Way Solenoid
5 – Check Valve
6 – Adjustable Opening Speed
7 – Adjustable Closing Speed
8 – Rate-of-Flow Control
9 – Orifice Plate Assembly
Y – Y-Strainer
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.
The Pump Control Valve with Rate-of-Flow Feature is designed to min-
imize the surges associated with the starting and stopping of pumps.
The valve slowly opens and closes as required to control pumping
related surges, and throttles to maintain a maximum flow rate during
the pumping cycle. The pump starts and stops against a closed valve.
Pump Start Up:
When the pump is signaled to start, the 3-Way
Solenoid is energized, directing pressure into the cover chamber of the
3-way Accelerator Pilot. The Accelerator Pilot allows the main valve
cover chamber to be vented downstream, causing the valve to open
at a controlled rate, gradually admitting pumping pressure into the
distribution system. The rate of opening is controlled by the adjustable
opening speed control, which restricts the speed of fluid and pressure
evacuating the main valve cover chamber. The valve remains open
during the pumping cycle.
Rate-of-Flow Feature:
During the pumping cycle, the valve acts
as a Rate-of-Flow Control Valve. Throttling (Flow Control) action is
controlled by a normally open, differential control pilot designed to: 1)
Open (allowing fluid out of the main valve cover chamber) when the
differential pressure across the orifice plate is below the adjustable set
point, and, 2) Close (allowing fluid to fill the main valve cover chamber
through the integral orifice of the Accelerator Pilot) when the differential
pressure across the orifice plate is above the adjustable set point. A
decrease in differential pressure causes the valve to modulate towards
an open position, increasing flow rate. An increase in differential pres-
sure causes the valve to modulate towards a closed position, decreas-
ing flow rate.
The Orifice Plate Assembly should be installed three to five pipe diam-
eters downstream of the Pump Control Valve, and field connected with
3/8
" minimum copper tubing in accordance with factory piping sche-
matic.
Please specify desired flow rate prior to ordering.
Pump Shutdown:
When the pump is signaled to turn off, the 3-Way
Solenoid is de-energized, venting the cover chamber of the 3-way
Accelerator Pilot. The Accelerator Pilot allows the main valve cover
chamber to be connected to upstream pressure, causing the valve to
close at a controlled rate. The valve slowly begins to close while the
pump continues to operate. The closing rate of the valve is controlled
by the adjustable closing speed control, which restricts the speed of
fluid and pressure entering the main valve cover chamber. When the
valve reaches the closed position, the limit switch is actuated, turning
the pump off.
Hydraulic Check Feature:
When the pump is turned off and down-
stream pressure is greater than upstream pressure, downstream pres-
sure is admitted to the main valve cover chamber through a check
valve in the pilot control system, closing the valve, preventing reversal
of flow.
Manual Operation:
Engaging the Solenoid Manual operator simulates
power to the solenoid, manually opening the main valve. Disengaging
the Solenoid Manual operator returns the valve to the closed position.
Series LF984GD
