Howden WRV, Service Manual

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6.1 PROCEDURES DURING SHUTDOWN
The Howden WRV Screw Compressor operates on an oil/gas mixture and short periods of shutdown
will not adversely affect the unit.
If the compressor is shut down for an extended period the lubricating oil pump should be operated
for approximately ten minutes weekly, to distribute oil throughout the set.
Turn the compressor driveshaft a few times every week by hand. This will help to avoid Brinelling of
the anti-friction bearings.
If the shutdown period is three months or more the above procedure should be continued and, in
addition, the compressor set should be run for one hour every three months.
Alternatively, for greater corrosion protection, the normal lubricating oil can be drained off, replaced
with inhibiting oil and the set run for one hour initially, then one hour every three months.
NOTE: Before the compressor set is returned to normal use, the inhibiting oil must be
removed and the system filled with regular oil.
During a shutdown period in cold conditions any water cooled items of plant should be drained, or
the cooling water flow maintained to prevent frost damage.
6.2 INHIBITING OILS APPROVED FOR USE WITH HOWDEN SCREW COMPRESSORS
A list of approved inhibiting oils suitable for use on the Howden Screw Compressor prior to a
prolonged shutdown is shown in Fig. 1.
If you have any doubts about the compatibility of these oils with your gas please contact the
manufacturer or your dealer.
SHELL ENSIS ENGINE OIL 10W
ESSO RUST-BAN 335 OR 337
MOBIL MOBILARMA 524
CALTEX CALTEX PRESERVATION OIL 10W
Fig. 1