4 - 8 Maintenance and Repair
4.7 Inlet and Purge Exhaust
Switching Valve Maintenance

(LS60 through LS760)

WARNING!
Ensure that the Dryer is de-energized, valve isolated,
and fully depressurized before attempting to remove
or disassemble any Dryer component or subassem-
bly. Failure to do so may result in serious personal
injury and/or equipment damage.
1. Clean and inspect all valve hardware upon disassem-
bly. Replace locknuts [13] and [16] and compression
springs [2] and [3]. Replace all software and any hard-
ware which appears damaged or abnormally worn.
Note: Locknuts [13] and [16] are not re-usable. Once
removed they MUST be replaced.
2. Clean and inspect valve seat located inside the valve
body [8].
3. Apply an ultra-thin film of O-ring lubricant to items [10],
[11], [15], and [23] before reassembly.
4. The U-cup piston seal [23] has been fitted with a cut
O-ring. Ensure that the U-cup piston seal is installed
on the valve pistons [21] and [22] as shown in Figure
4.3.
5. Apply a light coat of lubricant to sockethead cap
screw, item (4). Hand tighten screws until snug.
Torque as follows:
Torque 1/4 - 20 screws to 40 in-lbs.
Torque 5/16 - 18 screws to 135 in-lbs.
Switching Valve Components
Item Description Total
1 Machine Screw 4
2 Compression Spring (Purge Exhaust) 2
3 Compression Spring (Inlet) 2
4 Sockethead Cap Screw 12
5 Washer 2
6 Washer 2
7 Washer 2
8 Valve Body 1
9 Flange Cover 2
10 O-Ring (Valve Cover) 4
11 O-Ring (Shaft) 2
12 Rod Scraper 2
13 Locknut 2
14 Tetraseal 3
15 O-Ring (Inlet) 4
16 Locknut 2
17 Valve Cover 2
18 Valve Poppet (Purge Exhaust) 2
19 Connect Rod (Purge Exhaust) 1
20 Connect Rod (Inlet) 1
21 Valve Piston (Purge Exhaust) 2
22 Valve Piston (Inlet) 2
23 Piston Seal 8
Piston seal [23] orientation
on inlet valve piston [22].
Typical both sides.
Piston seal [23] orientation on
purge exhaust valve piston [21].
Typical both sides.
Figure 4.3