Floating ball valve

Fresh waters are, in general, less corrosive towards copper than is sea-water, and copper is widely and satisfactorily used for distributing cold and hot waters in domestic and industrial installations . Copper and copper alloys are used for pipes, hot-water cylinders, fire-back boilers, ball floats, ball valves, taps, fittings, heater sheaths, etc. In condensers and heat exchangers using fresh water for cooling, tubes of 70/30 brass or Admiralty brass are usually used, and corrosion is rarely a problem. 

A trunnion mount ball valve has the ball connected to a shaft above and below the ball. The upper shaft transmits the actuator torque to the ball and both shafts together hold the ball in a centralized position against the line pressure. Bearings are typically provided between the trunnion shafts and the valve body. The advantage of this approach is that a lower torque is required to move the ball when compared at similar pressures to a floating ball valve. 

A floating ball valve has a ball with an upper shaft to rotate the ball for operation. Upstream pressure on the ball pushes the ball into sealing contact with the downstream seat. Since the pressure acting on the ball is the diameter of the seat area and not the more limited seat area of the trunnion valve, floating ball valves normally require more torque to operate than an equivalent pressure trunnion ball valve. 

The failure rates of a floating ball valve have been estimated for different application conditions based on a detailed FMEDA of a ball valve. 

Estimate the water level. Does it appear normal or is it too low/high Do the ball valve and float mechanism work satisfactorily ... 

Both floating and trunnion-mounted designs are available with other design variations that include metal seied valves, soft seated valves, top-entry valves, end-entry valves, and split body valves. Valves in all these design variations are available as either full port or reduced port. Port refers to the round-bore fluid flow area through the ball. Full port valves have a bore that is approximately equal to the inside diameter of the mating pipe. Reduced port valves have a bore that is approximately equal to the inside diameter of pipe one size smaller than full bore. 

Continuous Cone.—As shown in Fig. 8 the stream of material enters the feed. spout A and, after passing through the truncated cone the water and solid particles which it is desired to remove flow upward and out into the overflow launder. The heavy particles settle in the cone and form the basin. When the settled material reaches the outlet of B it obstructs it so that the water rises in B lifting the float C, thereby lowering the ball G from the spigot by means of the lever D, the link E and the valve arm F. Once the cone is filled up a balance will be obtained and the settled solids will flow out in a continuous stream but the... 

The valve has floating seats on the upstream and downstream sides of the ball. In most trunnion designs, the differential pressure on the upstream seat provides the major loading to seal the seat to the ball. 

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