Flowserve SB Control Valves User Manual

Page 7

ShearStream SB

FCD VLENIM4152-01 07.09

10. Fitting the Actuator to the Valve

1. The actuator can be mounted directly on the

valve. The mounting ﬂ ange and the valve stem

follow the NAF standard for securing the

actuator.

2. Turn the valve to the closed position. The key

should face towards the inlet.

3. Fit the actuator.

4. Connect the compressed air supply to the

actuator - applies to pneumatic actuators. If the

end position stop is correctly set, the ball

segment will not move when compressed air

pressure is applied.

5. If moving - adjust the end position stop until the

actuator has turned the ball segment to the

closed position.

6. General

The actuator may be ﬁ tted either in line with the

connected pipes or transversely to them. An

intermediate plate is necessary for mounting the

actuator in line with the pipework.

N.B. The direction of closure must always be

clockwise, as viewed from the actuator.

Before ﬁ tting the actuator, it is important to ensure that

the actuator ﬁ ts the stem. First try without key to check

that the drive slips onto the shaft. Also check that the

key ﬁ ts and matches the keyways in the shaft. Grease the

actuator shaft entry. Push the actuator onto the stem.

The travel of the ball sector should be restricted to 90°,

which is the travel necessary between fully open and

fully closed. If the sector is turned beyond this range,

the sealing surfaces of the sector and seat ring may

be damaged when an attempt is made to turn the

ball sector back to the correct position and the sector

may jam against the seat ring.

In practice, this is prevented by the indicating pin which

will come into contact with the bolts retaining the top

cover if an attempt is made to turn the ball sector outside

the range between fully open and fully closed. When

adjusting the actuator, make sure that, in the closed posi-

tion, the sphere of the ball sector (2) is located opposite

the seat ring (11), i.e. that the sphere projects beyond the

seat ring by equal amounts on each side of the seat as

shown in Fig. 5.

clockwise, as viewed from the actuator.

Fig. 5. Locating of the ball sector sphere when

adjusting the actuator