Zurn Industries, LLC | Wilkins
1747 Commerce Way, Paso Robles, CA U.S.A. 93446 Ph. 855-663-9876, Fax 805-238-5766
In Canada | Zurn Industries Limited
3544 Nashua Drive, Mississauga, Ontario L4V 1L2 Ph. 905-405-8272, Fax 905-405-1292
www.zurn.com
Rev. C
Date: 10/16
Document No. BF-RV DISCHARGE
Product No. 375, 375A, 475 & 975
Relief Valve Discharge Rates
Reduced Pressure Principle &
Reduced Pressure Detector Back ow Preventers
General Information
Reduced Pressure Principle Backflow Preventers can and
will discharge water. For indoor installations, pit or vault
installations or protective enclosures, a drain needs to be
provided that can handle the amount of water discharged.
This chart shows the maximum amount of water that can be
discharged from the device based on the line pressure where
it is installed. Rarely will a device discharge this amount of
water, but if it does happen, it can cause flooding, building
damage or a cross-connection that can contaminate the wa-
ter supply. Therefore a drain MUST be sized properly. ZURN
WILKINS shall not be responsible for damage caused by the
lack of a drain or an undersized drain.
To reduce the risk of water damage due to relief valve dis-
charge, specify the ZURN WILKINS Model 375MS.
For additional information, send for BF-375MS, BF-375AMS
BF-475MS&VMS, BF-475&VMS212&3 and BF-FCIS
(Worst case condition - If 1st check or relief valve is lodged wide open)
1/4-1/2"
2-1/2-6"
3/4-1"
1 1/4-2"1/2-1" 1 1/4-2"
8-10"
