14
Primary Piping
SECTION IV - Primary Piping
General Piping Requirements
- All plumbing must meet or exceed all local,
state and national plumbing codes.
- Support all piping using hangers. DO NOT
support piping by the appliance or its com-
ponents.
- Use isolation valves to isolate system com-
ponents.
- Install unions for easy removal of the MOD-
ULATING DELTA from the system piping.
Pressure Relief Valve
1. The MODULATING DELTA is supplied
with a 30 psi pressure relief valve.
2. To avoid potential water damage to the sur-
rounding area or potential scalding hazard
due to the operation of the relief valve, the
discharge piping:
- Must be connected to the discharge out-
let of the relief valve and directed to a
safe place of disposal.
- Length should be as short and direct as
possible. The size of the discharge line
should not be reduced; maintain the
same size as the outlet of the relief valve.
- Should be directed downward towards
the floor at all times. The piping should
terminate at least 6 inches above any
drain connection to allow clear visibili-
ty of the discharge.
- Should terminate with a plain end, not
with a threaded end. The material of
the piping should have a serviceable
temperature rating of 250ºF or greater.
- Should not be subject to conditions
where freezing could occur.
- Should not contain any shut-off valves
or obstructions. No shut-off valve
should be piped between the appliance
and the relief valve.
Failure to comply with the guidelines on
installing the pressure relief valve and
discharge piping can result in personal
injury, death or substantial property
damage.
Low Water Cutoff Device
- The MODULATING DELTA is
equipped with a factory installed pres-
sure switch style Low Water Cut Off
device.
- The minimum operating system pres-
sure allowable with this device is 10
psig.
- Check local codes which require a low
water cutoff device for compliance of
this device.
Additional Limit Control
If a LWCO device is required by certain local
jurisdictions, the following guidelines must be
followed:
- The LWCO device must be designed
for water installations, electrode probe-
type is recommended.
- The LWCO device must be installed in
a tee connection on the supply or return
piping above the appliance.
- Wiring of the LWCO device to the
MODULATING DELTA is done direct-
ly onto the 24V terminal strip, refer-
ence Fig. 13 page 26 for available ter-
minals for an external limit (manual or
auto reset).
If an additional high temperature limit is
required by local code requirements the limit
should be installed as follows:
- Install the limit in the appliance supply
piping between the appliance and any
isolation valve.
WARNING
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