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1948-49 Theatre Catalog, 7th Edition, Page 455 (442)

1948-49 Theatre Catalog, 7th Edition
1948-49 Theatre Catalog
1948-49 Theatre Catalog, 7th Edition, Page 455
Page 455


1948-49 Theatre Catalog, 7th Edition, Page 455

Maintenance Tips for Users of Freon-12

Five Series of Suggestions for Theatremen

In Handling the Refrigerant and Cylinders

Careful attention to the maintenance of refrigeration systems will, as with other types of machinery and equipment, prolong life and usefulness. Previous editions of this publication have well covered the purely mechanical angles, with but passing reference to the refrigerant.

To close the hiatus in this field, the following maintenance suggestions are offered. Because Freon-12 is most widely used as the refrigerant in theatre airs conditioning systemseand the use is becoming more and more generalethese suggestions refer only to this material, provided by Kinetic Chemicals, Inc.

It should be remembered that, in a very real sense, the gas cylinders are a part of a refrigeration system. Ac cordingly, care in handling and using cylinders of Freon-12 will repay the owner, by helping him to prolong their life and maintain high operating effi> ciency of the system. And, of course, after being sure that all the Freon-12 paid for is completely evacuated from the cylinder, return it promptly.

Leak Detection

Leaks in refrigeration systems, particularly small ones, are often difficult to detect. Look for leaks at unions; at flanges where bolted together; at cylinder heads and' valve plates; on either side of valves, fittings, gaskets, and threaded connections. Time can often be saved by looking for an accumulation of lubricating oil which has leaked from the system. These other suggestions Will help.

(1) Use a Halide lamp to detect and positively locate the leak. When testing, the Freon-12 vapor escaping from the leak will cause the high temperature Hame of the lamp to change to a bright green color. Use of the Halide lamp is

EVAPORATOR

X = POINTS OF POSSIBLE LEAKAGE

UNIONS



CONDENSER

BOLTED

FLANGE RECEIVER

SERVICE VALVE a.

X' t!

LEAKS l'N REFRIGERATION SYSTEMS, particularly the small ones, are often difficult to detect. Look for leaks at unions; at flanges where bolted together: at cylinder heads and valve plates; on either side of valves,'tittinqs, gaskets, and threaded connections. Time can often be saved by looking for an accumulation at lubricating oil which has leaked out. In the drawing. x's indicate points of leakage.

the easiest and best method of detecting the most minute leaks.

(2) Close valves on both sides of leak, thus isolating it; relieve pressure in line by "cracking, or loosening the nearest connection, and remove gas from line to be repaired by blowing it out with air. Repair leak according to the problem at hand.

(3) Fill repaired section with inert gasesuch ascarbon dioxide or nitrogen wunder pressure. Use about 10 per cent Freon-12 as a tracer and test with Halide lamp as covered in detection. Do not use compressor to develop air pressure in line. For accurate testing, avoid lighting Halide torch in the room if

WHEN OPERATION of the equipment is not required, these important points on Freon-12 charged systems should be checked When the receiver is 0! sufficient capacity, valve B is closed and the refrigerant pumped into the receiver, after which valve A is closed. It the receiver capacity is insufficient, valves A. B, C, and D should be closed to isolate the refrigerant throughout the system.

I I V v EVAPORATOR C- 9.0 O; -D CONDENSER I = - a. d -.. ' RECEIVER . SERVICE VALVE '0 b. -B UNIONS . EXPANSION VALVE 9'4 9 E N '3 I

filled with Freon vapor. Do not fill test lamp with fuel in a room containing Freon, as the fuel will absorb the gas and give inaccurate readings.

Shutting Down Systems

Check these important points on shutting down Freon-12 charged systems during periods when operation of the equipment is not required. These tips will help you conserve Freon-12, save you time, trouble, and expense.

(1) Determine the capacity of the receiver. Make certain it will hold the entire charge of Freon-12 and still have a void, or gas space, which is 10 per cent of the receivers volume. This extra space is required to allow for expansion of the liquid refrigerant at higher temperatures, and eliminates the possibility of bursting the receiver because of hydrostatic pressure.

(2) When the receiver is of adequate capacity, close service valve B. Operate the compressor, to evaporate all liquid in the line between valve B and valve CFreon-12 then condenses, fiows into receiver. Reduce back pressure to from 2 to 5 pounds gauge reading, then close valve A.

(3) When the receiver is not of adequate capacity, close Valves A, B, C, and D to isolate the refrigerant in separate sections of the system.

(4-) Test all valves to guard against leaks during the shut-down period, as described in the previous section.

Emptying Cylinders

Today, the importance of con'ipletely emptying cylinders of Freon-12 cannot be over-emphasized. Haphazard methods

THEATRE CATALOG 1948-49
1948-49 Theatre Catalog, 7th Edition, Page 455