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1 = Braided graphite
2 = Die formet graphite (5 or 6 ring)
3 = Metal ring
Figure no. 3
Pressure Seal Gate Valves -Style A-
Installation and Maintenance Instructions
Section 3 - Maintenance
The Style A Series Valves have been designed to require minimum maintenance.
This manual describes on site repairs as:
- Packing Replacement
- Body/Bonnet Gasket Replacement
All the other repairs should be performed by Sapag or Nominated Service Company.
3.1. Packing Maintenance
If leakage is observed through the packing, tighten the gland nuts slowly and evenly until the
leakage stops.
Caution
Do not over-tighten packing gland nuts. Over-tightening will increase the torque required to
operate the valve.
When tightening the gland nut, use half-turn increments until leakage has stopped.
Please refer to Figure no. 4.
To replace the packing proceed as follows:
Warning
Before starting any maintenance, depressurize, drain and vent the line; check that the valves
are not in temperature; disconnect any electrical power supply.
Failure to do so may cause serious personal injury and/or equipment damage.
1.
Open completely the valve up to the backseat position.
2. Remove the nuts (16) of the gland bolts (15)
3. Lift the gland flange (10) and the gland (9)
4. Remove the worm-out packing using a hooking wire
5. For a better tightness, proceed to an accurate cleaning of the stem and stuffing box and make
sure there are no scratches or signs of seizing
6. The repacking shall be carried out by placing one ring at a time around the stem, inside the
stuffing box and by making sure that they are correctly oriented. Press it into the bottom (refer
to Figure no. 3).
7. When the stuffing box is filled, replace the gland (9) and gland flange (10) in their original
position.
8. Tighten gland nuts in accordance with Table I (Bolt Torque figures for Packing Bolts).
9. Cycle the valve.
10. Pressurize the line.
11. If a leakage is detected, tighten the gland nuts slowly and evenly until the leakage stops.
Figure no. 4
3.2 Bonnet Gasket Replacement
Warning
Before starting any maintenance, depressurize, drain and vent the line; check that the valves
are not in temperature; disconnect any electrical power supply.
Failure to do so may cause serious personal injury and/or equipment damage.
Emerson reserves the right to change the contents without notice
page 5
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