TYPES OF VALVES
Angle Valve Design
Figure 11 Angle Globe Valve
The angle body globe valve design, illustrated
in Figure 11, is a simple modification of the
basic globe valve.
Having ends at right
angles, the diaphragm can be a simple flat
plate. Fluid is able to flow through with only
a single 90 turn and discharge downward
more symmetrically than the discharge from
an ordinary globe. A particular advantage of
the angle body design is that it can function
as both a valve and a piping elbow.
temperature, and flow, the angle valve closely
resembles the ordinary globe.
valve's discharge conditions are favorable
with respect to fluid dynamics and erosion.
Globe Valve Disks
Most globe valves use one of three basic disk
designs: the ball disk, the composition disk,
and the plug disk.
The ball disk fits on a tapered, flat-surfaced seat. The ball disk design is used primarily
in relatively low pressure and low temperature systems. It is capable of throttling flow,
but is primarily used to stop and start flow.
The composition disk design uses a hard, nonmetallic insert ring on the disk. The insert
ring creates a tighter closure. Composition disks are primarily used in steam and hot
water applications. They resist erosion and are sufficiently resilient to close on solid
particles without damaging the valve. Composition disks are replaceable.
Because of its configuration, the plug disk provides better throttling than ball or
composition designs. Plug disks are available in a variety of specific configurations. In
general, they are all long and tapered.