York EX Series, Installation, Operation & Maintenance Instructions Manual

Page: 156 / 176

JOHNSON CONTROLS
156
FORM 155.32-ICOM1.EN.GB
ISSUE DATE: 10/13/2017
SECTION 7 – MAINTENANCE
TABLE 40 - WET STORAGE METHOD
PART STORAGE METHOD NOTES
Storage Period;
less than 2 months
Chilled/hot water line
Filled with water
1. The manual valve on the purge piping should be fully
closed See Figure 51 on page 131 .
2. If the storage period exceeds 2 months, algae and
bacteria may propagate and corrode the tubes
depending on the water quality, chemicals should be
fed to avoid such propagation.
3. If the storage period exceeds 2 months, water inside
the chiller-heater should be replaced periodically. If
the same water remains in the chiller-heater for a
long time, bacteria may propagate and corrode the
tubes depending on the environmental condition and
water quality. Hence, the chilled/hot water and cool-
ing water pumps should be operated for a short time
periodically and the water inside chiller-heater should
be replaced completely (at least once a month).
4. If the storage period exceeds 6 months, apply
pressure 0.01~0.02 Mpa with nitrogen inside the
shells and leave as it is. Internal-pressure should
be checked periodically (at least once a week) to
confirm that no pressure drop occurs.
Cooling water line
Inside of shells Vacuum
Storage Period;
more than 2
months and less
than 6 months
Chilled/hot water
system
Filled with water
Cooling water system
Inside of shells Vacuum
Storage Period;
more than 6
months
Chilled/hot water
system
Filled with water
Cooling water system
Inside of shells
Pressurized with Nitrogen
(0.01~0.02 MpaG)
TABLE 41 - DRY STORAGE METHOD
PART STORAGE METHOD NOTES
Storage Period;
less than 6 months
Chilled/hot water
system
Dried and pressurized with
Nitrogen (0.01~0.02 MpaG)
1. Chilled/hot water and cooling water systems
should be drained completely and dried by nitrogen
blow, then pressurized with nitrogen and left as is.
Depending on the water quality, hard scale may be
fixed on the inside surface of tubes by drying and
it can be removed only by chemical cleaning. For
more than 1 year’s storage, it is necessary to, after
cleaning the tubes, drain completely, dry up inside
by nitrogen blow, then pressurize with nitrogen and
leave as is.
2. If the storage period exceeds 6 months, apply
pressure 0.01~0.02 Mpa with nitrogen inside the
shells and leave as is. Internal-pressure should
be checked periodically (at least once a week) to
confirm no pressure drop occurs.
3. The manual valve on the purge piping should be
fully closed (See Figure 51 on page 131 and Figure
52 on page 132 .
Cooling water system
Inside of shells Vacuum
Storage Period;
more than 6
months
Chilled/hot water
system
Dried and pressurized with
Nitrogen (0.01~0.02 MpaG)
Cooling water system
Inside of shells Pressurized with Nitrogen
(0.01~0.02 MpaG)