In addition, there are different styles related to the bore of the ball mechanism itself:
A full port or more commonly known full bore ball valve has an over-sized ball so that the hole in the ball is the same size as the pipeline resulting in lower friction loss. Flow is unrestricted but the valve is larger and more expensive so this is only used where free flow is required, for example in pipelines which require pigging.
In reduced port or more commonly known reduced bore ball valves, flow through the valve is one pipe size smaller than the valve's pipe size resulting in flow area being smaller than pipe. As the flow discharge remains constant and is equal to area of flow (A) times velocity (V), the velocity increases with reduced area of flow.
作者: 中石油建設(shè)hy 時(shí)間: 2014-4-13 20:59
There are a few types of ball valves related to the attachment and lateral movement of the ball:
A trunnion ball valve has additional mechanical anchoring of the ball at the top and the bottom, suitable for larger and higher pressure valves (say, above 10 cm and 40 bars).
A floating ball valve is one where the ball is not held in place by a trunnion. In normal operation, this will cause the ball to float downstream slightly. This causes the seating mechanism to compress under the ball pressing against it. Furthermore, in some types, in the event of some force causing the seat mechanism to dissipate (such as extreme heat from fire outside the valve), the ball will float all the way to metal body which is designed to seal against the ball providing a somewhat failsafe design.作者: Zx。 時(shí)間: 2016-9-24 17:54
樓主6666666666666666作者: 設(shè)計(jì)初學(xué)者 時(shí)間: 2017-1-11 17:31
恩，很有知識(shí) 作者: 史斌 時(shí)間: 2017-2-13 16:36
竟然如此詳細(xì)、作者: chengcheng00166 時(shí)間: 2020-5-17 20:59
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the velocity increases with reduced area of flow.
