Nordson 25B - Cleaning, Inspection, and Parts Replacement; Ball Check Test; Packing Gland Replacement

© 2024 Nordson Corporation
1044131-06
7-5
25B Air Motor and Air Valve 25B 4:1 Hydraulic Section Repair
3
4
5
6
7
8
9
10
Figure 7-3 Separating the Air Motor and Hydraulic Section
3. Plunger 7. Lower back-up washer
4. Upper back-up washer 8. Ball
5. Energizing washer 9. O-ring
6. Piston cup 10. Pressure seat
Cleaning, Inspection, and Parts Replacement
Clean and inspect the housings, plunger, and solvent chamber for cracks or scoring.
Replace any cracked, deeply scored, or pitted parts. O-ring sealing surfaces must be
smooth and clean with no pitting.
Replace all O-rings and back-up rings. Lubricate them with O-ring lubricant before
installation.
Ball Check Test
Test the pressure and siphon ball checks for leaks by placing the seats on top of the balls
and pouring a small quantity of solvent into each seat. If the solvent does not leak from
the seats, you do not need to replace the seats or balls.
Packing Gland Replacement
NOTE:  Always lubricate the upper packing gland exterior O-rings and backup rings and
the lower packing U-cups with O-ring lubricant before installation.
Upper packing glands can be ordered separately. Except for Type G packings, the glands
are shipped completely assembled. Lower packings are included in the Hydraulic Service
Kits, and must be assembled on the plunger as shown in Figure 7-3. You should replace
both upper and lower packings at the same time.
NOTE:  The Type G Hydraulic Service Kits do not include upper packing gland housings
or internal retaining rings. Housings are not sold separately; you must reuse your
existing housings. Retaining rings can be ordered separately.