Howden WRV, Service Manual

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7.2 PREPARATION FOR ANNUAL INSPECTION
Before dismantling the compressor, certain precautions should be taken in the interests of safety:
1.
Isolate the drive unit.
2.
Depressurise and purge the system.
3. Disconnect the drive unit coupling from the compressor.
4. Place a receptacle under the outlet end of the compressor to catch any oil which may drip
from the hydraulic cylinder when the cylinder cover is removed or when the outlet end cover
is removed.
5. Ensure all lifting equipment, ie, eye bolts, slings, and shackles are safe and serviceable.
To enable a check to be made of floats and condition of seals and guide block on the compressor
during annual maintenance, a certain amount of dismantling is required. This differs slightly between
the 163 compressor and the 204, 255, 321 & 365 compressors.
7.3 DISMANTLING PROCEDURE FOR ANNUAL INSPECTION
Commence at discharge end with the Hydraulic Actuator
No matter which size compressor is involved, extract the 3 off cap screws holding the Aluminium
cover to the cylinder cover, if fitted, and remove. Extract the cap screws securing the Cylinder Cover
to the Hydraulic Cylinder and remove the cover, including the limit switches and indicator spindle
which are attached to it (Fig. 2).
NOTE: Some compressors will have a LPI sensor fitted as an option instead of switches, and will
not have the cylinder switch cover fitted.