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STI S.r.l.
– Via Dei Caravaggi 15, 24040 Levate (BG) – ITALY www.imi-critical.com
Manual 5400, rev. 05 02/2018
– RTQHS
21
8.2
Special maintenance
Under normal condition the actuator don’t need special maintenance. If there are leaks in the hydraulic
cylinder or a malfunction in the mechanical components, or in case of scheduled preventive maintenance,
the actuator must be disassembled and seals must be replaced with reference to the attached sectional
drawing and adopting the following procedures.
Important
Before performing any maintenance operations use always wear protective
gloves, clothing, and eyewear when performing any maintenance operations.
Warning
Before proceeding with any maintenance operation the following instructions
must be respected:
-
Disconnect any operating lines providing air pressure, electric power, or a
control signal to the actuator. Be sure the actuator cannot suddenly open
or close the valve
-
Close the hydraulic feed line and exhaust the pressure from the actuator
cylinder and from the control unit, to ensure safety of maintenance staff.
Warning
To release spring tension, the stop screw at the end of spring cartridge must be
remove before the cylinder tie rods are opened
.
Don’t open the spring package. The piston, spring, piston rod and head flange
are a pre-assembled package.
If the actuator need to be disassembled from the valve on site, remove the screws between the actuator and
the main valve or adaptor flange or mounting bracket (see Section 5.7 of this Manual).
