Watts 994HMB User Manual
Series 994HMB
Hydrant Meter Backflow Preventer
Sizes: 21⁄2" – 7NST x 3"
Model 994 HMB Hydrant Meter Backflow Preventer is for use
in measurement of potable water from a fire hydrant or other
non-permanent installation where flow is in one direction only
and the possibility of cross-connection exists. The Watts
994HMB fire hydrant preventer meter is designed to protect
the potable water system by preventing backflow through the
fire hydrant. This model can be used where approved by the
local authority having jurisdiction on health hazard cross-connections.
Features
• Heavy duty relief valve cover prevents vandalism and protects relief valve from damage when 994HMB is transported
to another fire hydrant location
• In-line flow restrictor protects the meter measuring element
and the backflow preventer components from damage due
to excessive flow
• Backflow preventer made from 300 Series stainless steel for
corrosion resistance
• Portable, lightweight design makes device easily transportable between job sites
• Accurately measures flow and protects the water supply from
possible contamination
• Built-in support leg is adjustable in the field
• Factory assembled and tested; no field assembly required;
eliminates leaks and improper assembly
Specifications
• Typical Operating Range (100%±1.5%): 5 to 660 gpm
(1.1 to 150 m
3
/h)
• Maximum Continuous Flow: 450 gpm (102 m
3
/h)
• Maximum Intermittent Flow: 660 gpm (150 m
3
/h)
• Typical Low Flow (Min. 95%): 4 gpm (0.9 m3/h)
• Pressure Loss at Maximum: 37psi @ 450 gpm (2.6 bar
@102 m
3
/h); standard couplings with orifice and screen
• Continuous Operation: 23psi @ 350 gpm
• Maximum Operating Pressure: 150psi (10.3 bar)
• Standard Hose Coupling: 2
1
⁄2" - 71⁄2 NST threads
National Standard thread fire hose coupling
Materials
All Internal Metal Parts: 300 Series Stainless Steel
Main Valve Body: 300 Series Stainless Steel
Check Assemblies: Noryl
®
Shutoff Valve: Brass
Relief Valve Guard: 300 Series Stainless Steel
Meter Materials
• Housing: Heat treated aluminum alloy
• Nose Cone and Straightening Vanes: Thermoplastic
• Rotor: Thermoplastic
• Rotor Radial Bearings: Lubricated thermoplastic
• Rotor Thrust Bearings: Sapphire jewels
• Rotor Bearing Pivots: Passivated 316 stainless steel
• Calibration Mechanism: Stainless steel and thermoplastic
• Flow Restriction Orifice: Heat treated aluminum alloy
• Magnet: Ceramic
• Register Cover: Bronze
• Trim: Stainless steel
• Inlet Screen: Stainless steel with elastomer
Maintenance
The Watts 994HMB fire hydrant backflow preventer meters are
designed and manufactured to provide long-term service with
minimal maintenance. When maintenance is required, it can be
performed easily either at the meter installation or at any other
convenient location. As an alternative to repair by the utility,
Watts can arrange various maintenance and meter component
exchange programs to fit the needs of the utility.
For Health Hazard Applications
ES-994HMB
Job Name
–––––––––––––––––––––––––––––––––––––––––––
Contractor
––––––––––––––––––––––––––––––––––––––––––––
Job Location
–––––––––––––––––––––––––––––––––––––––––
Approval
–––––––––––––––––––––––––––––––––––––––––––––
Engineer
–––––––––––––––––––––––––––––––––––––––––––––
Contractor’s P.O. No.
–––––––––––––––––––––––––––––––––––
Approval
–––––––––––––––––––––––––––––––––––––––––––––
Representative
––––––––––––––––––––––––––––––––––––––––
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.
IMPORTANT: INQUIRE WITH GOVERNING AUTHORITIES
FOR LOCAL INSTALLATION REQUIREMENTS
994HMB
Dimensions – Weights
• Overall lay length: 371⁄2" (953mm)
• Weight: 66 lbs. (30 kgs)
• Height from top of open gate valve to bottom
of relief valve: 19" (483mm)
• Width: 10" (254mm)
Capacity
Approvals
Model 994HMB Hydrant Meter Backflow Preventer meets the
design requirements of most national standards. Due to the
portability of the unit, there are no national approvals available.
Contact the factory for specific approvals on the reduced pressure backflow preventer.
ES-994HMB 0708 © Watts Regulator Company, 2007
81⁄4"
93⁄16"
371⁄2"
MODEL WEIGHT
lbs. kgs.
994HMB-GPM 66 30
994HMB-CFM 66 30
Pressure Loss
kPa psi
345 50
276 40
207 30
138 20
69 10
00
0 100 200 300 400 500 gpm
0 380 760 1140 1520 1900 lpm
USA: 815 Chestnut St., No. Andover, MA 01845-6098; www.watts.com
Canada: 5435 North Service Rd., Burlington, ONT. L7L 5H7; www.wattscanada.ca
Backflow Prevention Products
Typical Installation – Hydrant Meter Backflow
0100100010
10
5
Over
Register
+
0
-
5
Accuracy Per Cent
10
Under
Register
15
246 200 400 600 800820406080
Loading...