
For Non-Health Hazard Applications
ES-N9
Job Name 
Job Location 
Engineer 
Approval 
 ––––––––––––––––––––––––––––––––––––––––––––
 ––––––––––––––––––––––––––––––––––––––––––
 –––––––––––––––––––––––––––––––––––––––––––––
 –––––––––––––––––––––––––––––––––––––––––––––
Series N9 
Dual Check Vacuum Breakers  
for In-Line Applications
Size 1⁄4" and 3⁄8" (8 and 10mm)
Series N9 Dual Check Vacuum Breakers for In-Line Applications 
are used for continuous pressure, non-health hazard, applications.  
These valves have NPT female inlet and outlet connection and 
brass body construction. 
Models
N9C – same as N9 except comes with chrome body
Pressure-Temperature
Temperature Range: 33°F – 180°F (5°C – 82°C)
Maximum Working Pressure: 150psi (10.3 bar)
Applications
Series N9 should be installed on each parlor sink where a hose is 
attached. This series is for use on continuous pressure applications.
Parlor Sinks
Open End,  
only outlet on fixture
Drain
3
⁄8" Mixed 
Water 
Line
N9
 Contractor 
 Approval 
 ––––––––––––––––––––––––––––––––––––––––––––
 ––––––––––––––––––––––––––––––––––––––––––––––
  Contractor’s P.O. No. 
 Representative 
 –––––––––––––––––––––––––––––––––––––––––
Capacity
 kPa psi 
 345 50
 310 45
 276 40
 241 35 
 207 30
 172 25
 138 20
Pressure Drop
 103 15
 69 10
 35 5
 0 0
0 1 2 3 4 5 6 7 gpm 
0  3.8  7.6  11  15  19  23  27 lpm
 –––––––––––––––––––––––––––––––––––
N9
1
⁄4"
3
⁄8"
Flow
B
Dimensions — Weights
MODEL SIZE (DN) DIMENSIONS WEIGHT
in. mm in. mm in. mm in. mm lbs. kgs.
N9C1⁄4 6 23⁄8 60 11⁄4 32 1 25 .38 .17
3
N9C
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 without prior notice and without incurring any obligation to make such changes and modifications 
on Watts products previously or subsequently sold.
USA: Tel: (978) 688-1811 • Fax: (978) 794-1848 • www.watts.com 
Canada: Tel: (905) 332-4090 • Fax: (905) 332-7068 • www.watts.ca
ES-N9  1322    © 2013 Watts
⁄8 10 23⁄8 60 11⁄4 32 1 25 .38 .17
1
⁄4 6 23⁄8 60 11⁄4 32 1 25 .38 .17
N9
3
⁄8 10 23⁄8 60 11⁄4 32 1 25 .38 .17
N9
A B B1
B1
A
A Watts Water Technologies Company
Standards
CSA B64.8