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APPLICATIONS: For installation in
commercial fire lines or any water supply
system to detect leakage or unauthorized
use. Designed for horizontal installation.
CONFORMANCE TO STANDARDS: UL, ULC
listed; FM approved (2" and 3").
DESCRIPTION: HERSEY Model DC Detector
Check Valves consist of a main check valve
with a reinforced elastomeric seat, operated
by a weighted lever (available with optional
trim kit and bypass meter). The Model DC
prevents water from re-entering the potable
water system, while detecting leaks in the
fire sprinkler system or unauthorized use
of sprinkler system water.
The optional bypass is comprised of a shutoff
valve, swing check, and a Hersey Model MVR
magnetic turbine meter, or a Hersey Model
400/500 IIS positive displacement meter.
Solid state remote reading systems are
available for all meters offered with the
Model DC (see electronics section).
OPERATION: With the mainline valve
held closed by the weighted lever, any low
flow will be directed through the bypass
and measured by the bypass meter. When the
pressure loss through the bypass is approximately
4 psi, the mainline valve opens automatically,
allowing unrestricted flow.
The mainline
valve and check on the bypass prevent loss
of water from the system. Closing the inlet
shutoff valve permits in-line servicing
of the bypass meter while the mainline remains
in service.
END CONNECTIONS: Flange x Flange.
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Model Designation
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DC |
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Sizes |
2", 3", 12" |
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Maximum Working Pressure |
175 PSI |
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Hydrostatic Test Pressure |
350 PSI |
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Temperature Range |
33F to 100F |
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Standards |
UL, ULC listed; FM approved
(2" and 3") |
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Value Body |
Bronze - 2"; Epoxy
coated cast iron - 3" and 12" |
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Clapper Seat |
Reinforced elastomer
on a bronze seat |
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Optional Bypass Meter
Case |
Bronze |
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Optional Bypass Meter
Interior |
Plastic (400IIS) |
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Optional Bypass Meter
Register |
Sealed plastic. |
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