7 Servicing/Maintenance
27 of 38
ECOLINE GT 40
7367.8/06-EN
7.2.3.4 Removing the bonnet/cover gasket
1. Undo bonnet/cover nuts 920.3.
2. Pull the bonnet with the valve trim out of the body.
3. Completely remove bonnet/cover gasket 411.
7.2.4 Assembling the valve
7.2.4.1 General information/Safety regulations
CAUTION
Improper reassembly
Damage to the valve!
▷
Reassemble the valve in accordance with the general rules of sound
engineering practice.
▷
Use original spare parts only.
Tightening torques
Use an appropriate tool to tighten the fasteners crosswise.
7.2.4.2 Fitting the graphite gland packing
ü
The spare parts required are available.
ü
All dismantled parts have been cleaned and checked for wear.
ü
Any damaged or worn parts have been replaced by original spare parts.
ü
The stem is in the open position.
ü
Stem 200 and gland packing chamber are dry and free from grease. For packing
replacement, stem 200 is free from tarnish and deposits.
ü
The gland packing chamber is free from foreign matter.
1. Measure the height of the gland packing chamber.
2. Place the first packing end ring 461.2 flush onto the base of the gland packing
chamber by hand (use assembly sleeve if necessary).
3. Place packing rings 461.1 flush onto the fitted packing end ring by hand (use
assembly sleeve if necessary).
4. Place the second packing end ring 461.2 on top of the fitted packing rings by
hand.
5. Check that packing end rings 461.2 and packing rings 461.1 are positioned flush
against each other in the gland packing chamber.
6. Guide gland bush 456 into the gland packing chamber.
7. Fit gland follower 452.
8. Tighten the stuffing box nuts 920.2 by hand. Align gland follower 452 at a right
angle to the stem axis. Make sure that there is a uniform gap between gland
bush 456 and the stem.
9. Pre-compress the gland packing by evenly tightening stuffing box nuts 920.2
crosswise. Establish an initial pre-compression (by displacement) of 0.08 times
the total packing height in uncompressed condition, approx. 8 %.
10. Move the stem to the open position and closed position several times.
11. Then compress by another 0.02 times the total packing height in uncompressed
condition, approx. 2 %.
7.2.4.3 Shell testing and seat tightness testing following gland packing installation
1. Fill the valve with test fluid.
2. Apply test pressure for shell testing.
