Neles PB2 Series, Инструкция по установке, обслуживанию и эксплуатации, Страница: 6 / 12

1PB270EN - 10/2020 6
3. With a brush, clean body blots (15) and gland bolts (14)
of foreign material such as paint, thread locker, grime and
commodity. Inspect the threads for damage or defect with
appropriate ring or plug gage. Repair any out-of-tolerance
threads or replace in-kind.
4. Re-inspect all components for damage to the sealing areas,
stem (4), body (1), and cap (2). Replace any damaged parts.
5. Carefully clean and polish the ball (3) sealing surface: It should
be free of all scratches and grooves.
6. If the ball is damaged, or scratches are present, replace the ball.
7.
With the body cavity facing up, insert one valve seat (5) into
the body (1) to below the stem bore. Tilt the seat into place
and position so the proper surface will be in contact with the
ball.
8. Insert the stem (4) into the body (1), and press it gently up into
the stem.
9. Holding stem (4) in place from the bottom and insert the gland
packing (7) over the stem. See Figure 2 for proper V-ring
orientation.
7
Figure 3. V-ring packing orientation
10. Install the gland (6), washers (13), and gland bolts (14).
11. Tighten the gland bolts (14) evenly until the gland packing (7) is
compressed and then tighten an additional ¼ turn. Visually inspect
to ensure the gland (6) is parallel with top of actuator mounting
flange.
12. Rotate the stem (4) so the ball drive is in the closed position.
Place the ball (3) into the body cavity by partially rotating and sliding
the ball onto the stem (4) and against the seat (5). Make certain the
stem is roughly in the middle of the ball slot.
13. Place the second seat (5) into the cap (2) in the correct
orientation so the proper surface contacts the ball.
14. Carefully place the cap (2) on top of the body (1) and loosely
install the body nuts (16). Lightly lubricate bolts and face of nut with
anti-seize grease. Tighten the body nuts in an alternating sequence
across the body, gradually increasing the tightening torque in
multiple steps to applicable torque from Table 1 .
Table 1
Valve Size
Spec of Bolt holes Bolt torque Nm 0...+30%
NPS
1/2 M12 x 4 15
3/4 M12 x 4 15
1 M12 x 4 15
1 1/2 M16 x 4 44
2 M16 x 4 49
2.5 M16 x 4 53
3 M16 x 8 53
4 M16 x 8 104
6 M20 x 8 137
10. After fully tightening the gland packing and body joint flange,
operate valve to verify smooth operation during opening and
closing.
11. If the actuator was removed, reinstall and set the actuator
stops as described in the ACTUATOR MOUNTING
INSTRUCTIONS Section.
4.6 TESTING THE VALVE
WARNING:
WHEN PRESSURE TESTING, EXERCISE CAUTION
AND MAKE SURE ALL EQUIPMENT USED IS IN GOOD
WORKING CONDITION AND APPROPRIATE FOR THE
INTENDED PRESSURE.
If the valve is to be tested prior to returning to service, make sure
the test pressures are in accordance with an applicable standard.
When testing the valve for external tightness, keep the ball in the
half open position.
If testing for seat tightness, please contact Neles for advice.
WARNING:
WHEN PERFORMING ANY TESTS, NEVER EXCEED
THE MAXIMUM OPERATING PRESSURE OR MAXIMUM
SHUT-OFF PRESSURE LISTED ON THE IDENTIFICATION
PLATE.