Watts 6115-74JM - Manual

8550 Hansen Road . Houston, TX 77075 . Telephone 713.943.0688 . FAX 713.944.9445 www.wattsacv.com
Technical Bulletin Technical Bulletin
Pressure Reducing Control Valve Pressure Reducing Control Valve
with Low Flow By with Low Flow By -- Pass Pass
The Automatic Answer to Fluid Control
Model 6115-74JM
Part Number List
Item Description Complete Assembly Repair Kit
Model 6115-74JM 234803 3313-01
Reducing Pilot 0661-01 221101
Low Flow By-Pass Pilot 228803 5138-07
Operation
The Model 6115-74JM is designed to automatically reduce a fluctuating higher upstream (inlet) pressure to a
constant lower downstream (outlet) pressure across a broad range of flow requirements. It is controlled by a normally
open Pressure Reducing Pilot designed to: 1) Open (allowing fluid out of the main valve cover chamber) when
downstream pressure is below its adjustable setpoint, and, 2) Close (allowing fluid to fill the main valve cover
chamber) when downstream pressure is above its adjustable setpoint. A decrease in downstream pressure causes
the valve to modulate towards an open position, raising downstream pressure. An increase in downstream pressure
causes the valve to modulate towards a closed position, lowering downstream pressure.
The Low By-Pass Pilot is piped “around” the Main Pressure Reducing Control Valve, and is set approximately 10 psi
higher. Flow requirements below the range of the Main Pressure Reducing Valve are handled by the Low Flow By-
Pass Pilot. When flow requirements exceed the capacity of the Low Flow By-Pass Pilot, the Main Pressure
Reducing Control Valve opens supplementing flow and pressure. As the flow demand decreases, the Main Pressure
Reducing Valve closes, and the Low Flow By-Pass resumes command of flow and pressure.
Standard Components
1) Main Valve
2) Reducing Pilot
3) Supply Orifice
4) Adjustable Opening Speed
5) Position Indicator
6) Flow Clean Strainer
7) Ball Valve
8) Low Flow By-Pass Pilot
1
P /
L 4
2
Flow
Flow Direction: Under the Seat
3
5
6
7
8
Closes Valve
Opens Valve