Howden WRV, Service Manual

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7.4 CHECKING CLEARANCES
Guide Block
The guide block which locates the slide valve should also be checked for wear every 30,000 hours or
every 4 years whichever comes first. See Fig. 22 and relative table for dimensions.
Guide Block to Slide Valve Slot
Compressor Size
by
Rotor Diameter
Dimension ‘W’
Clearance
163 mm 24.987/24.975 mm
(0.984”/0.9833”)
0.046/0.013 mm
(0.0018”/0.005”)
204mm 29.987/29.975 mm
(1.181”/1.180”)
0.046/0.013 mm
(0.
0018”/0.005”)
255mm 41.262/41.250 mm
(1.625”/1.624”)
0.050/0.013 mm
(0.002”/0.005”)
321mm 44.990/44.965 mm
(1.771”/1.770”)
0.060/0.010mm
(0.0024”/0.004”)
365mm 49.991/49.965mm 0.065/0.009mm
(0.0025”/0.004”)
Fig. 22