| Tweet |
Custom Search
|
|
|
||
 TM 55-1905-220-14-8
4-32.
STRAINER - AIR CONDITIONING - MAINTENANCE INSTRUCTIONS.
a. Refrigerant-12 acts as a cleanser, loosening particles of dirt and scale which will collect in the
strainers. Clean liquid line strainers soon after a plant is placed in operation and, after that, as often as
required. Dirty liquid line strainer screens will throttle and cause some expansion, so that a difference in
temperature on either side of a strainer indicates a stoppage and the need for cleaning.
b. To remove and clean a liquid line strainer screen, first pump down strainer. Close cut-out valve on
inlet side of strainer and allow plant to pump down. As pressure is reduced, the strainer will become cold and
then begin to warm up as soon as liquid refrigerant has been removed. At that time, close cut-out valve on
outlet side of strainer, that is, downstream of thermal expansion valve. (The automatic control valves,
expansion and solenoid, have also been isolated and can be disassembled for cleaning, repair or replacement
as required.)
c. Remove flange strainer cover and strainer screen. Plug strainer to exclude air and moisture. Clean
screen thoroughly and reinstall leaving flanged cover partly disconnected. Slightly open cut-out valves on both
sides of strainer one at a time and allow a small quantity of refrigerant to blow the air out of the line. Then
quickly tighten strainer cover. Open cut-out valves to place strainer and automatic control valves back on the
line.
NOTE
When strainer and automatic control valves are isolated for
service, liquid refrigerant flow to circuit may be continued by
opening hand expansion valve in bypass line. Crack hand
expansion valves open gradually (about -turn at a time) and
not too much to avoid flooding.
4-952
|
||
|
||
