No
P2903.4.2 requires backflow prevention or a check valve if you have water heating equipment installed
A pressure reducing valve may not be designed to prevent backflow
P2903.3.1 Maximum pressure.
The static water pressure shall be not greater than 80 psi (551 kPa). Where the main pressure exceeds 80 psi (551 kPa),
an approved pressure-reducing valve conforming to ASSE 1003 or CSA B356 shall be installed on the domestic water branch main or riser at the connection to the water service pipe.
Performance Requirements for Water Pressure Reducing Valves for Potable Water Distribution Systems
Organization: | ASSE |
Publication Date: | 1 December 2020 |
Status: | Active |
Page Count: | 20 |
Scope:
Description
Devices covered by this standard are self-contained, direct acting, single diaphragm types. Devices shall be permitted to have an integral strainer, separate strainer connected to the valve inlet, or be without strainer.
Devices shall be permitted to be with or without an integral by-pass relief valve.
P2903.4.1 Pressure-reducing valve.
For water service system sizes up to and including 2 inches (51 mm), a device for controlling pressure shall be installed where, because of thermal expansion, the pressure on the downstream side of a pressure-reducing valve exceeds the pressure-reducing valve setting.
P2903.4.2 Backflow prevention device or check valve.
Where a backflow prevention device, check valve or other device is installed on a
water supply system using storage water heating equipment such that thermal expansion causes an increase in pressure, a device for controlling pressure shall be installed.