Watts 957Z - Manual

For Health Hazard Applications
Note: These curves
represent catastrophic
or worst case discharge
rates. These curves
were developed by pres-
surizing the outlet of
the backflow preventer
with the second check
valve’s internals removed
from the body.
1 ⁄
4
", 3 ⁄
8
", 1 ⁄
2
" 009QT
3 ⁄
4
" 009M3QT
1" 009M2QT
lpm gpm
266 70
228 60
190 50
152 40
114 30
76 20
38 10
0 0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 psi
0 .7 1.4 2.0 2.8 3.5 4.1 4.8 5.5 6.2 6.9 7.6 8.3 9.0 9.7 10.3 11.0 11.7 12.4 bar
Rate of Flow
Rate of Flow
Rate of Flow
Pressure
Pressure
0 10 20 30 40 50 60 70 80 90 100 psi
0 69 138 207 276 345 414 483 552 621 690 kPa
Pressure
lpm gpm
152 40
133 35
114 30
95 25
76 20
57 15
38 10
19
5
0 0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 psi
0 .7 1.4 2.0 2.8 3.5 4.1 4.8 5.5 6.2 6.9 7.6 8.3 9.0 9.7 10.3 11.0 11.7 12.4 bar
lpm gpm
228 60
190 50
152 40
114 30
76 20
38 10
0 0
Watts product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements,
please contact Watts Technical Service. Watts 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 Watts products previously or subsequently sold.
Series 009, 909, 919, 957 and 994
Reduced Pressure Zone Assemblies
Relief Valve Discharge Rates
ES-RVD
Job Name ––––––––––––––––––––––––––––––––––––––––––– Contractor ––––––––––––––––––––––––––––––––––––––––––––
Job Location ––––––––––––––––––––––––––––––––––––––––– Approval –––––––––––––––––––––––––––––––––––––––––––––
Engineer ––––––––––––––––––––––––––––––––––––––––––––– Contractor’s P.O. No. –––––––––––––––––––––––––––––––––––
Approval ––––––––––––––––––––––––––––––––––––––––––––– Representative ––––––––––––––––––––––––––––––––––––––––