Flowserve SB Control Valves User Manual

Page 6

ShearStream SB

FCD VLENIM4152-01 07.09

Remove the compression spring (10) in the

same way.

Carefully wash all parts with warm water and

then, if necessary, with a suitable solvent. Never

scrape the sealing surfaces with hard tools.

Examine the surface of the ball sector (2).

Remove any deposits and clean the ball sector

as described in item 6 above.

N.B. Take care not to scratch the sealing

surface of the ball sector.

Inspect the seat ring (11) and clean it as

described in item 6 above.

9. Inspect the sealing ring (12) - it need not be

removed from its groove in the body. Fit a new

sealing ring if the original one is damaged.

10. Lubricate the ball segment with a suitable

lubricant, such as Molykote Paste U, Gleitmo

700 or similar.

11. Lubricate the surface of the sealing ring (12)

with a silicone-base grease, such as Silicone

grease DC 111, Silicone grease TKM 1011 or

similar.

12. Fit the compression spring (10) and seat ring (11).

Turn the ball sector (2) until it is in contact with

seat ring (11). Use a soft object to press the

seat ring towards the compression spring (10)

to enable the ball sector to move into its proper

position. Continue turning the sector to the

closed position.

13. Fit the indicating pin (23).

N.B. An additional function of the indicating

pin is to restrict the travel of the ball segment

to 95 - 100°, so that it will always remain in

contact with the seat ring.

9.3 To inspect and replace the upper shaft seal of

Safeguard type

The stufﬁ ng box usually requires inspection and adjust-

ment after the valve has been taken into service.

After a certain period of time in service, it may some-

times also be necessary to replace the packing.

Make sure that the valve is not under pressure.

If an actuator is ﬁ tted to the valve, remove it.

Begin by removing the valve positioner. This

can easily be done after the plastic cover of the

valve positioner has been removed. Remove the

four bolts securing the valve positioner to the

actuator. Then remove the nuts securing the

actuator to the valve mounting plate and dismantle

the actuator.

Remove the key.

Remove the nuts (18). Remove the gland (5).

Then remove the packing (19).

pin is to restrict the travel of the ball segment

to 95 - 100°, so that it will always remain in

contact with the seat ring.

4. Clean the surfaces of the stem, gland (5) and

packing area in the valve body.

5. Carefully examine the surface of the stem which

must be completely free from marks and

scratches.

6. Grease the stem with a suitable grease, such as

Silicone grease.

7. Mount new packing (19). Then mount the gland

(5) and the nuts (18).

8. Tighten the nuts (18) sufﬁ ciently to ensure that

the packing is correctly seated.

Note: Check the tightness of the packing after the

valve has been taken into service, retighten the

nuts (18), if necessary.

9.4 To inspect and replace the upper shaft seal of

Zebra CL™ type

The stufﬁ ng box usually requires inspection and adjust-

ment after the valve has been taken into service.

After a certain period of time in service, it may some-

times also be necessary to replace the packing.

1. Remove the actuator as described in section 9.3,

tems 1. Remove the keys (22) and the indicator

pin (23).

2. Remove the nuts (18), spring cups and gland (5).

Then remove the packing (19).

3. Clean the surfaces of the stem, gland (5) and

packing area in the valve body.

4. Carefully examine the surface of the stem which

must be completely free from marks and

scratches.

5. Grease the stem with a suitable grease, such as

Silicone grease.

6. Mount new packing (19) when mounting the

gland (5) and the spring cups and then the

nuts (18).

7. Tighten the nuts (18) sufﬁ ciently according to the

torque table in catalogue sheet FCD NFEETB4152-01

to ensure that the packing is correctly seated.

Note: Check the tightness of the packing after the

valve has been taken into service.

9.5 To change the gasket at the lower stem

1. The gasket (7) should be replaced in conjunction

with the inspection of the seat ring (11).

2. Remove the bolts (20) and the cover (6).

3. Withdraw the stem (4) and remove the gasket (7).

4. Carefully clean the inside of the cover (6) and the

stem (4).

5. Fit a new gasket (7) and lubricate the small end

of the stem with a suitable lubricant, such as

Molykote Paste U or Gleitmo 700.

6. Fit the stem (4) with the gasket (7).

7. Spray the bolt threads with locking compound,

such as Loctite 641.

8. Fit the cover (6) and tighten the bolts (20).