| 11. | These types of valves include globe valves, rising stem ball valves, control valves and gate valves.
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| 12. | Cone valves or ball valves are another alternative.
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| 13. | If the pipeline contains butterfly valves, or reduced port ball valves, the pipeline cannot be pigged.
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| 14. | A ball valve uses a spherical ball instead.
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| 15. | Historically, petcocks were threaded valves controlled by a butterfly handle; modern petcocks are typically ball valves.
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| 16. | One piece ball valves are almost always reduced bore, are relatively inexpensive and generally are throw-away.
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| 17. | Larger check valves may be installed with ball valves at the ends, for isolation and testing.
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| 18. | Some ball valves are equipped with an actuator that may be pneumatically, hydraulically or motor operated.
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| 19. | Manually operated ball valves can be closed quickly and thus there is a danger of water hammer.
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| 20. | A floating ball valve is one where the ball is not held in place by a trunnion.
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