Idiomas disponibles
Idiomas disponibles
Installation Guidelines
Pressure — Temperature
Working Temperature
Maximum Pressure
Minimum Pressure
Requirements
• Install 12" above the highest point of downstream piping.
(See Figure 1.)
NOTICE
Installation as stated above is essential for proper operation
• Install bonnet side up and allow access for testing/service.
• Install where discharge or spillage is not objectionable.
• Do not undersize supply or oversize the valve relative to
demand.
• Do not install where backpressure can occur.
•
Protect from freezing. For freeze protection, specify Model
800M4FR or LF800M4FR. Or, consider the WattsBox insu
lated enclosure. For more information, download ES-WB at
www.watts.com.
Follow ASSE Standard 1020 that the atmospheric vent valve
•
remains open until the valve body pressure exceeds 1 lb.
Until this pressure is reached, some amount of spillage
occurs at the atmospheric vent. To minimize this leakage on
start-up, close the downstream shutoff valve and open the
inlet shutoff valve quickly.
Start-up Procedure
1. Close shutoff No. 2 (outlet).
2. Open shutoff No. 1 (inlet) until water discharges from the
bonnet then quickly open to pressurize the valve.
3. Open shutoff No. 2.
Freeze Protection
Use the following procedure to purge the PVB assembly with
pessurized air. (See Figure 2.)
1. Close the main shutoff valve.
2. Open upstream drain, test cocks and isolation ball valves to
depressurize line.
3. Purge with pressurized line.
4. Leave test cocks and isolation ball valve handles in 45°
angle to drain ball valves and prevent casting damage.
Typical Installation
The TWS hydrant is usually included in the PVB installation to
provide outside access to a building water supply for start-up,
winterizing, and servicing of irrigation sprinkler systems. (See
Figure 3.) The hydrant is connected to the PVB assembly and
installed through the structure wall to connect to the water
supply.
2
33°F to 140°F (0.5°C to 60°C)
150 psi (10.3 bar)
15 psi (103 kPa)
Figure 1
12" Minimum Clearance
WattsBox
Above the Highest Point of
Downstream Piping
Figure 2
Union
Main Shutoff Valve
Upstream (Inlet) Drain
Figure 3
Water
Supply
Outlet Drain
Valve
12" Minimum Clearance
Above the Highest Point of
Downstream Piping
Valve Pit
Sprinkler
System
Flow
Piping
To Sprinklers
Key
Watts TWS
Drain Port or
Blow Down
