_____________________________________________________________________________________
STI S.r.l.
– Via Dei Caravaggi 15, 24040 Levate (BG) – ITALY www.imi-critical.com
Manual 5400, rev. 05 02/2018
– RTQHS
25
8.2.3 Reassembling
8.2.3.1
Hydraulic cylinder re-assembling.
Carefully clean the inside of the tube and check that the entire surface, particularly that of the bevels, is not
damaged. Lubricate with a protective oil or grease film the tube internal surface and the bevels at the ends.
Lubricate every seal groves taking care there are not damages on seal surfaces.
Slide cylinder tube onto the piston taking care not to damage the o-ring: the tube bevel has to smoothly
compress the piston seal ring; take care also not to damage the head flange O-ring.
Assemble the end flange by centering it on the inside diameter of the tube, taking care not to damage the O-
ring.
Assemble the nuts (please refer to cylinder sectional dwg.) onto the tie rods. Tighten the nuts to the
recommended torque as per Table 1 in sec. 5.6.2, alternating between opposite corners.
8.2.3.2
Actuator re-assembling
Assemble the hydraulic cylinder to the housing tightening, with recommended torque table, the screw
between cylinder and housing. Replace o-ring at the bottom of the housing making attention there are not
dirty or damage on the seal surface, put the bushing on its seat. Re-assemble scotch yoke and guiding
block, make a generous coating of grease on the contact surfaces of yoke and the bushings, assemble the
guide bar after that screw the plug into the housing to complete the bar guide assembling. Tighten the screw
between cylinder piston rod and guiding block, with recommended torque, using a wrench.. Assemble the o-
ring, the cover gasket and the cover with all screw.
Recommended tighten torque as per Table 1 in Section 5.6.2.
8.3
Repairs
When needed, repair must only be carried out with STI
’s original spare parts.
Original spare parts must be required to the STI with reference to the Table/Item numbers shown in the next
Section 10.
To ensure that right spare is provided,
serial number
printed on the RTQHS series label must be specified
when spares are ordered.
Important
After maintenance operations carry out a few actuator operations to check that
its STROKING is regular and that there is no leak through the seals and fittings.
Summary of Contents for STI RTQH Series
Page 41: ......
