Installation Guide

3
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ES1602 REV A.
BFMMRP4ASBF
I. DESCRIPTION AND OPERATION
The Reduced Pressure Principle (RP) device consists of two independently-acting, spring-loaded check valves, together with a hydraulically dependent,
mechanically independent pressure dierential relief valve, located in the zone between the check valves. Two resilient seated shut-o valves and four
test cocks complete the assembly.
The first check is designed to maintain a minimum of 5 psi across the check valve. The second check is designed to maintain a minimum of 1 psi across
the check valve during normal operation. The relief valve operates on a dierential pressure. Supply pressure on the upstream side of the first check
valve acts against the diaphragm to close the relief valve during normal operation. In the event of back-pressure, the relief valve will open to maintain
the pressure in the “zone” at least 2 psi less than the inlet pressure. The flowing and no flow conditions are illustrated in Figures 1 and 2. A minimum
supply pressure of 20 psig is normally required to fully shut the relief valve and open both checks.
II. INSTALLATION
A. The RP must be installed in an accessible location to facilitate periodic field testing and maintenance.
B. The location selected should have adequate drainage for relief valve discharge. The device should never be placed where it may be submerged in
standing water.
C. Flush all upstream piping thoroughly to remove foreign matter prior to installing the device.
D. The device must be installed in the horizontal position. A clearance between the lower most portion of the device and flood grade or floor should
be provided for ease of maintenance.
E. When shut-o valves are provided separately, they should be installed with a test cock on the upstream side of the inlet shut-o valve.
F. After installing the assembly and with downstream or #2 shut-o valve closed, pressurize the device and bleed ALL air through test cock #4. Then
open #2 shut-o valve.