Product Overview

ES-F-825Y
S P E C I F I C A T I O N S H E E T
FEBCO product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise mea-
surements, please contact FEBCO. FEBCO reserves the right to change or modify product design, construction, specifications, or materials
without prior notice and without incurring any obligation to make such changes and modifications on FEBCO products previously or subse-
quently sold.
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Series 825Y
Reduced Pressure Zone Assemblies
Size:
3
⁄4" - 2" (20mm - 50mm)
The FEBCO Series 825Y 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 protection.
Features
• Ultimatemechanicalprotectionofpotablewater,againsthazards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.
• Flowcurvegenerated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 independently
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 main-
tain the proper differential.
Mainlinevalvebodyandcapsincludingreliefvalvebodyandcovershall
bebronze.Checkvalvemovingmembershallbecenterstemguided.All
hydraulic sensing 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removable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 revers-
ible.Shutoffvalvesandtestcocksshallbefullportedballvalves.
Theassemblyshallberatedto175psi(12.1bar)workingpressureandwater
temperaturerangefrom32°Fto140°F(0ºC-60ºC).
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 maintained closed.
Should abnormal conditions arise under no flow or reversal of flow, the
differential relief valve will open and discharge to maintain 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 minimum
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 eas-
ily 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.
825Y
Flow
30" Max. (700mm)
12" Min. (300mm)