1" 919 rv, 2" 919 qt, Rate of flow pressure – Watts 957Z User Manual
Page 4: Rate of flow, Pressure, Rate of flow pressure pressure
Typical Flow Rates as
sized by floor drain
manufacturers
Drain
Size
gpm
lpm
55
209
2
112
426
3
170
646
4
350
1330
5
2
1
⁄
2
" – 10" 957
Rate of Flow
Pressure
lpm gpm
1330 350
1140 300
950 250
760 200
570 150
380 100
190 50
0
0
0
20
40
60
80
psi
0
138
276
414
552
kPa
ES-RVD 0904
© Watts, 2009
USA: 815 Chestnut St., No. Andover, MA 01845-6098; www.watts.com
Canada: 5435 North Service Rd., Burlington, ONT. L7L 5H7; www.wattscanada.ca
Wa t e r S a f e t y & F l o w C o n t r o l P r o d u c t s
40
80
120
160
200
240
280
300
0
900
800
700
600
500
400
300
200
100
0
2
1
⁄
2
" – 10" 994
Rate of Flow
0
40
80
120
160
200
240
280
psi
0
276
552
827
1103
1379
1655
1931
kPa
Pressure
lpm gpm
3420 900
3040 800
2660 700
2280 600
1900 500
1520 400
1140 300
760 200
380 100
0
0
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" 919 RV
Capacity w/Second Check Removed
2" 919 QT
Backpressure w/Second Check
Poppet & Spring Removed
Rate of Flow
Rate of Flow
Pressure
Pressure
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 7.8 8.3 9.0 9.7 10.3 11.0 11.7 12.4
bar
0 10
20 30
40
50
60
70
80 90 100 110
psi
0
.7
1.4 2.1 2.8 3.5 4.1 4.8 5.5 6.2 6.9 7.6
psi
lpm gpm
228 60
190 50
152 40
114 30
76 20
38 10
0
0
lpm gpm
684
180
170
6.8
160
570
150
532
140
130
456
120
110
380
100
342
90
304
80
266
70
228
60
190
50
152
40
114
30
76
20
38
10
0
0