ments which may apply to the arrangement of these com-
ponents in the fire sprinkler system water supply.
Figure 2 illustrates a typical arrangement using the
Model S370 Automatic Residential Domestic Shutoff
Valve. The arrangement may need to be modified to meet
the requirements of the authority having jurisdiction; how-
ever, the Model S370 Automatic Residential Domestic
Shutoff Valve must be installed in accordance with the fol-
lowing criteria:
1. The S370 Valve is to be installed vertically with the Sup-
ply Port at the bottom, the Fire Sprinkler Port at the top,
and the Domestic Port at the side. It is recommended
that a suitable clamp be installed along the water supply
riser piping to provide support for the weight of the S370
Valve.
2. The water supply to the S370 Valve must be free of con-
taminants and particles of a size greater than 1/8 inch
(3.2 mm).
3. The S370 is to be installed so that the arrows cast on
the Body point in the direction of flow.
4. A Domestic Control Valve is to be located between the
S370 Valve and the domestic system. The inlet to the
Domestic Control Valve is to be located within 12 inches
(300 mm) of the Domestic Port of the S370 Valve.
5. The Drain and Flow Test Connection (Ref. Figure A)
must be minimum 1/2 inch for systems per NFPA 13D
or minimum 1 inch size for systems per NFPA 13R.
6. An Inspector’s Test Connection with a test orifice equal
to the smallest K-factor sprinkler in the system is to be
located at the most hydraulically demanding location in
the system (usually adjacent to the highest and most re-
mote sprinkler).
7. Apply pipe thread sealant sparingly only to the 2 inch NPT
male pipe threads which are to be assembled to the three
ports of the S370 Valve. The use of a Teflon
† based pipe
thread sealant is recommended.
STAR SPRINKLER INC.
2-7.1.10
Page 3
FIGURE 3
STANDBY AND OPERATED POSITIONS OF THE
2 INCH (50 mm) MODEL S370 AUTOMATIC RESIDENTIAL DOMESTIC SHUT-OFF VALVE
SPRINKLER
SEALS
SEAL
WATERFLOW TO
FIRE SPRINKLERS
WATERFLOW
SYSTEM
WATERFLOW
FROM SUPPLY
WATERFLOW
FROM SUPPLY
STANDBY
OPERATED
FIRE
DOMESTIC
TO DOMESTIC
PASSAGE
FLOW
DOMESTIC
(CLOSED)
(ENGAGED)
PISTON STOP
MECHANICAL
FIRE
SPRINKLER
PASSAGE
FLOW
(OPEN)
SPRINKLER
PASSAGE
(CLOSED)
FLOW
FIRE
(OPEN)
DOMESTIC
PASSAGE
FLOW
SPRING
PISTON
OBSOLETE
