Refrigerant Relief Piping; Typical Refrigerant Vent Piping From Relief Valves - York MILLENNIUM YS Manual

ers) in the piping as close to the unit as possible, to aid in
obtaining operating checks.
FLOW SWITCHES (FIELD INSTALLED)
A flow switch or pressure differential control in the chilled
water line(s), adjacent to the unit, is an accessory fur-
nished for connection to the control center. If a flow
switch is used, it must be directly in series with the unit
and sensing only water flow through the unit. The dif-
ferential switch must sense pressure drop across the
unit.
DRAIN AND VENT VALVES
Drain and vent valves (by others) should be installed in
the connections provided in the cooler and condenser
liquid heads. These connections may be piped to drain if
desired.
CHECKING PIPING CIRCUITS AND VENTING AIR
After the water piping is completed, but before any wa-
ter box insulation is applied, tighten and torque the nuts
on the liquid head flanges (to maintain between 30 and
60 ft. lbs. / 41 and 81 nm). Gasket shrinkage and handl-
FIG. 10 – TYPICAL REFRIGERANT VENT PIPING FROM RELIEF VALVES
YORK INTERNATIONAL
ing during transit cause nuts to loosen. If water pres-
sure is applied before this is done, the gaskets may be
damaged and have to be replaced. Fill the chilled and
condenser water circuits, operate the pumps manually
and carefully check the cooler and condenser water
heads and piping for leaks. Repair leaks as necessary.
Before initial operation of the unit both water circuits
should be thoroughly vented of all air at the high points.

REFRIGERANT RELIEF PIPING

Each unit is equipped with relief device(s) on the cooler,
condenser and oil separator for the purpose of quickly
relieving excess pressure of the refrigerant charge to
the atmosphere in case of an emergency. The relief
device is furnished in accordance with ASHRAE-15 and
set to relieve at 300 psig (2069 kPa). The rupture disk
on the oil separator is set at 345 psig (2379 kPa) and
sized to accomodate the compressor pumping capacity.
Refrigerant relief vent piping (by others), from the re-
lief valves to the outside of the building, is required by
code and should be installed on all units. The vent line(s)
should be designed in accordance with ASHRAE-15 or
local code(s). Refer to Figures 10, 11 and Table 4. For
additional information on relief valve discharge line siz-
ing, refer to Form 160.47-AD2.
FORM 160.47-NOM3
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LD03298
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