54
SERVICE
Servicing Coolers and Condensers —
When cool-
er heads and partition plates are removed, tube sheets are ex-
posed showing the ends of tubes. The 30GX,HX units use a
flooded cooler design. Water flows inside the tubes.
TUBE PLUGGING — A leaky tube in one circuit can be
plugged until retubing can be done. The number of tubes
plugged determines how soon the cooler must be retubed. All
tubes in the 30GX and 30HX coolers and 30HX condensers
can be removed. Loss of unit capacity and efficiency as well as
increased pump power will result from plugging tubes. Failed
tubes should be replaced as soon as possible. Up to 10% of the
total number of tubes can be plugged before retubing is neces-
sary. Figure 14 shows an Elliott tube plug and a cross-sectional
view of a plug in place. The same components for plugging
and rolling tubes can be used for all coolers and 30HXC con-
densers. See Table 39. If tube failure is in both circuits, using
tube plugs will not correct problem. Contact your Carrier rep-
resentative for assistance.
RETUBING (See Table 40) — When retubing is to be done,
obtain service of qualified personnel experienced in boiler
maintenance and repair. Most standard procedures can be fol-
lowed when retubing the 30GX and 30HX heat exchangers. A
7% crush is recommended when rolling replacement tubes into
the tubesheet. A 7% crush can be achieved by setting the
torque on the gun at 48 to 50 in.-lb (5.4 to 5.6 N-m).
The following Elliott Co. tube rolling tools are required:
B3400 Expander Assembly
B3405 Mandrel
B3401 Cage
B3408 Rolls
Place one drop of Loctite No. 675 or equivalent on top of
tube prior to rolling. This material is intended to “wick” into
the area of the tube that is not rolled into the tube sheet, and
Table 39 — Plugging Components
Table 40 — Tube Diameters
prevent fluid from accumulating between the tube and the tube
sheet. New tubes must also be rolled into the center tube sheet
to prevent circuit-to-circuit refrigerant leakage.
TIGHTENING COOLER/CONDENSER HEAD BOLTS
O-Ring Preparation — When reassembling cooler and con-
denser heads, always check the condition of the O-ring(s) first.
The O-ring should be replaced if there are any visible signs of
deterioration, cuts or damage. Apply a thin film of grease to the
O-ring before installation. This will aid in holding the O-ring
into the groove while the head is installed. Torque all bolts
to the following specification and in the sequence shown in
Fig. 15.
3
/
4
-in. Diameter Perimeter and
Plate Bolts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 to 225 ft-lb
(271 to 305 N-m)
Use extreme care when installing plugs to prevent damage
to the tube sheet section between the holes.
COMPONENTS FOR PLUGGING
PART NUMBER
For Tubes
Brass Pin
853103-1A*
Brass Ring
853002-640*
For Holes without Tubes
Brass Pin
853103-1A*
Brass Ring
853002-738*
Roller Extension
S82-112/11
Loctite
No. 675†
Locquic
“N”†
*Order directly from: Elliott Tube Company, Dayton, Ohio.
†Can be obtained locally.
ITEM
INCHES
MILLIMETERS
Tube sheet hole diameter:
0.756
19.20
Tube OD
0.750
19.05
Tube ID after rolling:
0.650
16.51
(includes expansion
to
to
due to clearance)
0.667
16.94
NOTE: Tubes replaced along heat exchanger head partitions must
be flush with tube sheet.
SHELL BOLTS
OUTLET FOR
MOTOR COOLING
LINE CONNECTION
STEPPER MOTOR
HARNESS
MOUNTING
BRACKET
BOLTS
STEPPER MOTOR
FLOAT
ASSEMBLY
DISCHARGE GAS
BUBBLER TUBE
OUTLET TO BOTTOM
OF COOLER
LIQUID INLET
TUBE FROM
CONDENSER
PIN AND RING INSTALLED
TUBE SHEET
PIN
TUBE
RING
PIN
RING
Fig. 13 — 30GX,HX Cutaway View of
Economizer Assembly
Fig. 14 — Tube Plugging
