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•Checking the valve
•Remove the vent plug or assembled accessories from the valve cover.
•Check that the valve spindle moves easily by raising and lowering it with the threaded rod. Special
attention must be paid to this test procedure, above all with valves with modified counter seats.
Putting back into service
•according to Commissioning paragraph
Functional check of the valve
•The function of the valve can be checked by actuating the solenoid valves (according to table in
section Principle of operation).
2.3 4 to 5-year maintenance
Cleaning the dirt trap in the main line
•Unscrew the lid
•Clean filter (use soft brushes, cloths or similar), or possibly replace filter
•Install the filter and screw the lid back on
Cleaning the filter in the control line
•Unscrew the lid of the filter
•Clean filter (use soft brushes, cloths or similar), or possibly replace filter
•Re-install the filter and screw the filter lid back on
Base valve (see chapter: Repair kits and spare parts)
•Loosen the screw connections and remove the complete control line.
•Dismantle the optical position indicator or assembled accessories and replace the gaskets.
•Undo the screws of the valve cover and remove the cover.
•Visually inspect all inner components for wear, dirt and scaling
•Clean the inner components, the seat and the inner surfaces, including the cover
•Dismantle the spindle guide in the body, flush the body interior.
For valves DN 40 to DN 100 (from 2012 on) and DN 125 to DN 200 (from 2014 on) the spindle guide
is dismantled from the inside. Here the thread of the spindle guide and the base valve must be
extremely clean. Grease the thread thoroughly (e.g. Foodgrease Aqua, Art. no. 5292, see chapter
"Control line individual parts and accessories”).
•Replace the diaphragm, the O-ring and the seat seal.
•Grease the spindle guide area with a grease suitable for contact with food (e.g. Foodgrease Aqua).
Check the easy movement of the spindle by lifting and lowering with the spindle lifting tool (article
number 1199, see chapter "Control line individual parts and accessories”).
•Reassemble the base valve (see table in the annex for torques). During the assembly, the easy
movement of the spindle must be checked with the spindle lifting tool by lifting and lowering several
times.
Functional check of the one-way flow restrictor
•Undo the locknut
•Screw in the throttle screw, and then unscrew it as far as it goes
•Screw in again a few turns. This process must be easy and meet little resistance
Checking the valve
•Remove the vent plug or assembled accessories from the valve cover.
•Check that the valve spindle moves easily by raising and lowering it with the threaded rod. Special
attention must be paid to this test procedure, above all with valves with modified counter seats.