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page 6
Rovalve S20
Installation and Maintenance Instructions
6. Stem nut replacement instructions
Replacement of the stem nut assembly on a Rovalve S20 is very simple. It is not necessary, or
desired, to remove the yoke assembly to replace the nut.
Tools required:
1. Pipe wrench or large crescent wrench
2. Appropriate size open end wrench for retainer bolts
CAUTION
Follow required safety procedure and policies. Use proper lifting and support techniques
when moving valve and or valve subassemblies.
Prepare the valve:
1. Line should be depressurized or gate secured prior to disassembly. If valve is equipped with
pin-style lockouts (see figure 12) gate can be locked in the open or closed position using the
lock pin. If pin-style lockouts are not present, the gate must be held in place to prevent
unwanted movement. These precautions are necessary to keep the gate from moving.
Disassembly:
1. Using pipe wrench or crescent wrench, remove handwheel retaining nut from stem nut.
2. Remove handwheel.
3. Remove (2) or (4) retainer bolts.
4. Pull retainer off
5. Rotate old stem nut until free from stem.
Reassembly:
1. Rotate new stem nut until it bottoms against top plate.
2. Place retainer over stem nut, lining up the bolt holes.
3. Replace retainer bolts and nuts, tighten completely.
4. Place handwheel over stem nut, aligning the hex.
5. Attach new handwheel retainer nut, using pipe wrench or crescent wrench, tighten completely.
6. Grease as required using grease fitting.
Figure 11
Handwheel
Stem Assy.
#1 Retaining nut
#2 Stem nut
Retainer
Retainer bolt
Yoke post (qty 4)
Grease fitting
