ABB LP10, Manual, Page: 13 / 42

LP LINEAR PISTON ACTUATORS INSTRUCTION MANUAL
11
Very little maintenance is required for the
operation of the LP actuator; the cylinders are
permanently lubricated at the factory.
MAJOR MAINTENANCE:
To replace rod bushing seals:
1. Remove socket head cap screws that
hold the bushing retainer to the cylinder
and remove the bushing. Remove old
seals and replace with new seals
making sure that you use some lubricant
such as Magnalube “G” (supplied with
kit) to aid inserting seals into grooves.
2. To replace the rod bushing assembly,
lubricate the inside and outside of the
bushing lightly and slide over the piston
rod by turning the bushing clockwise
while pushing the bushing gently over
the piston rod.
3. Replace the retainer; replace the socket
head cap screws one by one being sure
that all screws are loosely assembled so
as not to cock the bushing in the head.
Now tighten each screw just a little at a
time to prevent binding of the bushing in
the head. The following are the torque
values of these socket head cap screws
that hold the retainer in place:
#10-32 S.H.C.S used on 2” & 2 ½” Bore 5 ft-lbs
¼-28 S.H.C.S. Used on 3¼” to 10” Bore 12 ft-lbs
To Replace Piston seals:
1. Disassemble the cylinder by loosening
the tie rod nuts at either end of the
cylinder, using standard box end or
open-end wrenches. Remove the head
and bushing assembly from remaining
cylinder; now pull piston rod assembly
gently from the cylinder tube. Remove
piston seals from grooves in piston,
being careful not to scratch the bottom
of the grooves, as this may allow some
small amount of leakage by the piston
when the cylinder is put into operation
again. Place new seals in piston
grooves, being careful not to cut or nick
the new piston seals. mmmmmmmmmm
Be sure the seal lips are pointing
outward toward each end of the piston.
It is usually wise to remove and replace
the tube end seal in the head and cap at
the same time.
2. Clean entire inside of the cylinder tube,
piston rod assembly, and all other parts
of the cylinder to be assembled. Coat
piston O.D. and seals with a light
grease, (Magnalube “G” is
recommended) before assembly of
cylinder.
Reassemble cylinder in the following manner:
1. Place cap end on table with tube groove
facing up.
2. Position cylinder tube in tube groove.
3. Insert piston rod assembly into tube
making sure lip of the piston seal enters
the tube properly. Insert fully to bottom
of tube.
4. Place head and bushing over the end of
the piston rod pushing gently while
turning the head bushing assembly
clockwise until the bushing has cleared
the wrench flat area of the piston rod.
5. Be sure the cylinder tube is seated into
the cylinder tube groove in the head.
6. Replace the tie rods one by one, being
sure that all four are loosely assembled
so as to allow the head and cap to
rotate slightly so that the head and cap
will be squarely in line while you finish
torquing the tie rod nuts. Be sure to
tighten each nut a little at a time so as to
prevent binding of the cylinder. Use the
following torque on the tie rod nuts:
2” – 2 ½” Bore 12-14 ft-lbs
4” Bore 35 ft-lbs
6” Bore 50-55 ft-lbs
8” Bore 110 ft-lbs
10” Bore 125 ft-lbs
4.0 MAINTENANCE INSTRUCTIONS