Ii. operation, Iii. maintenance – NIBCO 3-Piece Bronze Ball Valves User Manual
Page 2
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D. CAUTION
1. Care must be taken to avoid scratching the machined sealing surface of the end
piece.
2. Over tightening of body bolts could result in damage to end piece.
3. Excessive temperature or uneven heating could result in damage to end piece.
4. Changing the radial location of the seat rings could result in leakage through the
seat.
II.
OPERATION
A. Valve is operated by rotating the handle clockwise a quarter-turn to close or counter-
clockwise a quarter-turn to open. The handle is in alignment with the opening
through the ball.
B. Valve can be used for throttling, provided the flow rate is not high enough to create
cavitations.
C. Valve will provide bubble-tight seal in closed position when used in accordance with
pressure/temperature chart published by NIBCO.
D. Media which can solidify, crystallize or polymerize should not be allowed to stand in
ball valve cavities.
E. Liquids trapped around the outside of the ball should not be subjected to excessive
increases in temperature.
III. MAINTENANCE
If seepage is noted around the stem, tighten packing nut (Item 3, exploded view) to the torque
specified in Table 2.
TABLE 2
Valve
Torque
(Ft./Lbs.)
595,
1/4”
4
–
6
595,
3/8”
4
–
6
595,
1/2”
4
–
6
595,
3/4”
12
–
15
590,
1-1/4”
12
–
15
595,
1”
12
–
15
590,
1-1/2”
15
–
20
595,
1-1/4”
15
–
20
590,
2”
15
–
20
595,
1-1/2”
15
–
20
590,
2-1/2”
15
–
20
595,
2”
15
–
20
590,
3”
45
–
55
595, 2-1/2”
45 – 55