Series 9DM2, 9DM3
Dual Check with Atmospheric Vent
Sizes:
1
⁄
2
",
3
⁄
4
" (15, 20mm)
Model 9DS- Remove union connections before sweating
• The 9D Dual Check with Atmospheric Vent is designed for use on non-health hazard,
continuous pressure, point of use applications for protection against backsiphonage
and backpressure. Install in accordance with the local codes.
• For the best system performance, install on the fresh water feed line before any pres-
sure regulators (such as the Watts Series 1156 on a residential boiler application).
• Flush the line before installing the unit to remove any solder, flux or pipe chips. Clean
the strainer every six months or as conditions require.
• Some discharge is expected, particularly on start-up, until all seating surfaces seal.
Continuous discharge is an indication that the internal seating parts and surfaces may
require the cleaning.
• May be installed horizontally or vertically.
• Quick closing valves, water hammer or supply pressure fluctuations can cause inter-
mittent discharge. The installation of a Water Hammer Arrestors (Watts Series 05) or
Water Pressure Regulator (Watts Series 1156 or 25AUB) may be required to correct
the problem.
NOTICE
It is important not to install where the
discharge could cause damage. Pipe
the discharge line in accordance with
local code requirements. A physical air
gap must be maintained between the
discharge pipe and the drain or sump.
Create the air gap by cutting the pipe
on a 45° bevel, at a distance of 12"
above the floor. If used on boiler appli-
cations do not use an air gap fitting
at face level so as to prevent personal
injury from scalding water or steam. In
no event should the vent opening or drain line be plugged.
• If local codes require the device be tested, it must be installed as shown in
the drawing on the reverse side.
RP/IS-9D
9D Total Repair Kits
EDP No.
KiT No.
SizE
0886010
RK 9DM2 T
1
⁄
2
",
3
⁄
4
" (15, 20mm)
0886011
RK 9DM3T
1
⁄
2
" (15mm)
Kit includes: primary & secondary checks, seat
and two union seals.
Boiler installation
Watts 9DM3 Heating System Installation
Supply
Boiler
Return
Vent
Drain
Floor Drain
Integral
Strainer
Watts Model 1156F Feed
Valve with Union
Watts
9DM3
WARNING
!
Read this Manual BEFoRE using this equipment.
Failure to read and follow all safety and use information can
result in death, serious personal injury, property damage, or
damage to the equipment.
Keep this Manual for future reference.
NOTICE
Inquire with Governing Authorities for Local
Installation Requirements
NOTICE
