40
Table 6: Torque to apply for steel bushings
BUSHING TYPE
BOLT SIZE
TORQUE, FT – LBS
H
1/4 - 20 X 3/4
8
SH, SDS
1/4 - 20 X 1 3/8
9
SD
1/4 - 20 X 1 7/8
9
P1, P2, P3
5/16 – 18 X 1
16
SK
5/16 – 16 X 2
15
Q1, Q2, Q3
3/8 –16 X 1 1/4
29
R1, R2
3/8 – 16 X 1 3/4
29
SF
3/8 – 16 X 2
30
S1, S2
1/2 - 13 X 2 1/4
70
E
1/2 - 13 X2 3/4
60
F
9/16 – 12 X 3 5/8
75
4.
SPECIAL JOINT TORQUE REQUIREMENTS
Any joints not covered by the above, such as special fasteners or special materials like
an aluminum fan hub or fan blade bolts may require special torque requirements. If any
of these type joints require attention, consult Rocore engineering.
D.
CORE CLEANING
The cooler cores may become clogged with leaves, paper or dirt, or may become coated
with oil or dust. Any of these conditions may result in reduced cooler performance.
Cleaning the core can be done with compressed air, steam, or water spray.
CAUTION! The core fins are very delicate and can be bent or damaged by high
pressure close to the core.
E.
FANS
For all fans, clean any accumulated scale or foreign matter from the fan assembly when
you perform the regular maintenance. Also, for all fans, check the fan for any cracks,
dents or corrosion.
Plate-hub fans manufactured by AirFlo Cooling Technologies (formerly Chittom) with
model numbers starting with 7E, 12F, 18T, 24T or P (fan model numbers are shown on
the radiator datasheet) require regular maintenance. These aluminum-bladed fans are
assembled and installed on Rocore radiators in the Rocore facility according to the fan
manufacturer’s specifications in regards to blade pitch, tracking, tip clearance and bolt
torque.
These fans should be inspected for damage, blade pitch angle and the correct hardware
torques (listed below) after the first full week of operation and at intervals not greater
than six months thereafter. Be sure to follow all safety precautions, including proper
lockout/tagout procedures, before inspecting or performing maintenance.
Taper-lock bushing bolts
3/8” bolts, 35 ft-lbs
1/2” bolts, 45 ft-lbs
Blade clamp bolts
1/2" bolts, 50 ft-lbs
5/8” bolts, 90 ft-lbs