Specification

ES-F-LF825Y
The FEBCO Series LF825Y Reduced Pressure Zone Assemblies
are used to protect against high hazard (toxic) fluids in water
services to industrial plants, hospitals, morgues, mortuaries, and
chemical plants. They are also used in irrigation systems, boiler
feed, water lines and other installations requiring maximum pro-
tection. The LF825Y features Lead Free* construction to comply
with Lead Free* installation requirements.
Features
• Ultimate mechanical protection of potable water, against haz-
ards of cross-connection contamination.
• Meets all specifications of AWWA, ASSE, CSA and approved
by the Foundation for Cross-Connection Control and Hydraulic
Research at the University of Southern California.
• Approved by the Foundation of Cross-Connection Control and
Hydraulic Research at the University of Southern California.
• Modular relief valve for ease of maintenance.
• Simple Service procedures. All internal parts serviceable in line.
• Low head loss.
• Spring loaded “Y” type check valves.
• Internal relief valve pressure sensing passages.
• Replaceable seat rings on all sizes.
• End connection – NPT ANSI / ASME B1.20.1
Specifications
The reduced pressure zone assembly shall consist of two inde-
pendently operating, spring loaded, “Y” pattern check valves and
one hydraulically dependent differential relief valve. The assembly
shall automatically reduce the pressure in the “zone” between the
check valves to at least 5psi lower than inlet pressure. Should the
differential between the upstream and the zone of the unit drop
to 2psi, the differential relief valve shall open and maintain the
proper differential.
Mainline valve body and caps including relief valve body and
cover shall be Lead Free* cast copper silicon alloy. Check valve
moving member shall be center stem guided. All hydraulic sens-
ing passages shall be internally located within the mainline and
relief valve bodies and relief valve cover. Diaphragm to seat area
ratio shall be 10:1 minimum. Relief valve shall have a remov-
able seat ring. Check valve and relief valve components shall
be constructed so they may be serviced without removing the
valve body from the line. All seat discs shall be reversible. Shutoff
valves and test cocks shall be full ported ball valves.
The assembly shall be rated to 175psi (12.1 bar) working pres-
sure and water temperature range from 32°F to 140°F (0ºC -
60ºC). The Lead Free* Reduced Pressure Zone Assemblies shall
comply with state codes and standards, where applicable, requir-
ing reduced lead content.
The assembly shall meet the requirements of ASSE Standard 1013;
AWWA Standard Code C511; CSA Standard B64.4; and approved
by the Foundation for Cross-Connection Control and Hydraulic
Hydraulic Research at the University of Southern California.
Operation
In a flow condition the check valves are open with the pressure
between the checks, called the zone, being maintained at least
5.0psi lower than the inlet pressure and the relief valve is main-
tained closed.
Should abnormal conditions arise under no flow or reversal of
flow, the differential relief valve will open and discharge to main-
tain the zone at least 2psi lower than the supply.
When normal flow resumes, the zone’s differential pressure will
resume and the relief valve will close.
Typical Installation
Reduced pressure zone assemblies should be installed with mini-
mum clearance of 12" (300mm) between relief valve discharge
port and floor or grade. They must be installed where discharge
will not be objectionable and can be positively drained away.
They should be installed where easily accessible for testing and
maintenance and must be protected from freezing. Thermal water
expansion and/or water hammer downstream of the backflow
preventer can cause excessive pressure. Excessive pressure
situations should be eliminated to avoid possible damage to the
system and assembly.
Refer to local codes for specific installation requirements. Some
codes may prohibit vertical installation.
30" Max. (700mm)
12" Min. (300mm)
Flow
Series LF825Y
Reduced Pressure
Zone Assemblies
Size:
3
⁄4" - 2"
LEAD FREE
*
LF825Y
NOTICE
For Health Hazard Applications
Job Name
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Contractor
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Approval
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Engineer
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Contractor’s P.O. No.
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Approval
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Representative
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FEBCO product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements,
please contact FEBCO Technical Service. FEBCO reserves the right to change or modify product design, construction, specifications, or materials with-
out prior notice and without incurring any obligation to make such changes and modifications on FEBCO products previously or subsequently sold.
* The wetted surface of this product contacted by consumable
water contains less than 0.25% of lead by weight.