FORM 160.52-O1
57
YORK INTERNATIONAL
COMMERCIAL ACID CLEANING
In many major cities, commercial organizations now
offer a specialized service of acid cleaning coolers and
condensers. If acid cleaning is required, YORK recom-
mends the use of this type of organization. The Dow
Industries Service Division of the Dow Chemical Com-
pany, Tulsa, Oklahoma, with branches in principal cit-
ies is one of the most reliable of these companies.
TESTING FOR COOLER AND CONDENSER
TUBE LEAKS
Cooler and condenser tube leaks in R-134a systems
may result in refrigerant leaking into the water circuit,
or water leaking into the shell depending on the pres-
sure levels. If refrigerant is leaking into the water, it can
be detected at the liquid head vents after a period of
shutdown. If water is leaking into the refrigerant, sys-
tem capacity and efficiency will drop off sharply. If a
tube is leaking and water has entered the system, the
cooler and condenser should be valved off from the
rest of the water circuit and drained immediately to pre-
vent severe rusting and corrosion. The refrigerant sys-
tem should then be drained and purged with dry nitro-
gen to prevent severe rusting and corrosion. If a tube
leak is indicated, the exact location of the leak may be
determined as follows:
1. Remove the heads and listen at each section of
tubes for a hissing sound that would indicate gas
leakage. This will assist in locating the section of
tubes to be further investigated. If the probable lo-
cation of the leaky tubes has been determined, treat
that section in the following manner (if the location
is not definite, all the tubes will require investiga-
tions).
2. Wash off both tube heads and the ends of all tubes
with water.
NOTE: Do not use carbon tetrachloride for this pur-
pose since its fumes give the same flame
discoloration that the refrigerant does.
3. With nitrogen or dry air, blow out the tubes to clear
them of traces of refrigerant laden moisture from
the circulation water. As soon as the tubes are clear,
a cork should be driven into each end of the tube.
Pressurize the dry system with 50 to 100 PSIG of
nitrogen. Repeat this with all of the other tubes in
the suspected section or if necessary, with all the
tubes in the cooler or condenser. Allow the cooler
or condenser to remain corked up to 12 to 24 hours
before proceeding. Depending upon the amount of
leakage, the corks may blow from the end of a tube,
indicating the location of the leakage. If not, if will
be necessary to make a very thorough test with the
leak detector.
4. After the tubes have been corked for 12 to 24 hours,
it is recommended that two men working at both
ends of the cooler carefully test each tube one
man removing corks at one end and the other at
the opposite end to remove corks and handle the
leak detector. Start with the top row of tubes in the
section being investigated. Remove the corks at the
ends of one tube simultaneously and insert the ex-
ploring tube for 5 seconds this should be long
enough to draw into the detector any refrigerant gas
that might have leaked through the tube walls. A
fan placed at the end of the cooler opposite the
detector will assure that any leakage will travel
through the tube to the detector.
5. Mark any leaking tubes for later identification.
6. If any of the tube sheet joints are leaking, the leak
should be indicated by the detector. If a tube sheet
leak is suspected, its exact location may be found
by using a soap solution. A continuous buildup of
bubbles around a tube indicates a tube sheet leak.
