Válvula reguladora de presión diferencial Watts USVR - Q-Tech ®

USVR relief valve WATSS

Usual price €84,99
Tax included.
9 in stock

Relief valve for systems with automatic or manual shut-off elements on the radiators (thermostatic valves, two-way zone valves). Female inlet connections, Male union outlet. Body and cap of brass CW617N.
Adjustment: Position “0” = Fully open - Position “7” = Close to closing Δp =0.5 bar 

Plastic knob. Max operating pressure : 6 bar.
Overpressure : 10 - 15%. Max operating temperature : 110°C


By-pass valves series 466 and USVR are used in all heating systems in which the heating units are provided with thermostatic valves, zone valves or electrothermic valves series 22C.

The above mentioned regulation systems, control the room temperature adjusting the flow rate in the heating units. When thermostatic or electrothermic valves close could create noise problems and high differential pressure values on the opened valves of the circuit. This forces the pump to work continually in variable conditions reaching important differences from the initial pump head. The fitting of the by-pass valves between the delivery and the return side of every load line enables resonably costant discharge to be maintained.


The By-Pass valve will open assuring a constant water flow through the heat generator (very important for gas boiler) and increasing the return temperature to the heat generator (anti corrosion function).

The reliability of the pressure relief valve series 466 or USVR are factory controlled on 100% of the production.


By-pass valve series USVR can be set in this way:

• Thighten blocking screw (1) (see overall dimensions).
• Set the USVR valve at the differential opening pressure ΔP by turning regulation knob (2) (see overall dimensions).
The differential opening pressure DP shall exceed the user circuit load loss at rated discharge by approximately 20% in order that avoid valve opening be prevented. When the user circuits is completely closed, the USVR valve shall be fully open.
• Turn regulation knob anticlockwise untilscale (3) (see overall dimensions) indicates zero. Then proceed, turning clockwise, to calibration setting at the number required. Each number from 0-7 revers to an USVR16 - USVR20 USVR25 - USVR32.
• Once the correct setting is established, it can be fixed with the locking screw of the handwheel (1).

Available models:

- 1" - H-M

- 1 1/4" - H-M