Ames Fire & Waterworks LFM500, LFM500N, LFM500Z Lead Free Stainless Steel Reduced Pressure Detector Assemblies - Manual (Page 2)

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Guidelines
1. Most field problems occur because dirt and debris present
in the system at the time of installation becomes trapped
in the #1 check.
The system should be flushed before
the valve is installed. If the system is not flushed until after
the valve is installed, remove both check modules from the
valve and open the inlet shutoff to allow water to flow for a
sufficient time to flush debris from the water line. If debris in
the water system continues to cause fouling, a strainer can
be installed upstream of the backflow assembly.
2. The Series M400, M500, LFM500 may be installed in either
horizontal, “N” pattern, or “Z” pattern position as long as the
backflow assembly is installed in accordance with the direc-
tion of the flow arrow on the assembly and the local water
authority approves the installation.
3. The assembly should be installed with adequate clearance
around the valve to allow for inspection, testing and servic-
ing. 12" (300mm) should be the minimum clearance between
the lower portion of the assembly and the floor or grade. The
valve should be protected from freezing.
4. Installing a backflow preventer in a pit or vault is not
recommended.
5. Normal discharge and nuisance spitting are accommodated
by the use of an Ames air gap fitting and a fabricated indirect
waste line. Floor drains of the same size must be provided in
case of excessive discharge.
6. The M400, M500 and LFM500 backflow preventer should be
tested by a certified tester at the time of installation.
NOTICE
Assembly body should not be painted.
Horizontal Installation
Basic Installation Instructions
Relief Valve Discharge
2 1 /
2
" – 10" (65-250mm) Colt/Maxim 400 & 500, LF500
0 20 40 60 80 psi
0 138 276 414 552 kPa
lpm gpm
1330
350
1140 300
950 250
760 200
570 150
380 100
190 50
0 0
Rate of Flow
Pressure