upward when the valve is opened. In some rising stem
valves, the stem projects above the handwheel when
the valve is opened. The purpose of the rising stem is to
allow the operator to see whether the valve is opened or
The name is derived from the globular shape of the
valves; however, other types of valves may also have
globe-shaped bodies, so do not jump to the conclusion
that a valve with a globe-shaped body is actually a
globe valve. The internal structure of a valve, not the
external shape, is what distinguishes one type of valve
In a globe type of stop valve, the disk is attached to
the valve stem. The disk seats against a seating ring or a
seating surface that shuts off the flow of fluid. When
the disk is removed from the seating surface, fluid can
pass through the valve in either direction. Globe valves
may be used partially open as well as fully open or fully
The fluid flow is proportionate to the number of
turns of the wheel in opening or closing the globe
valve. The globe valve is ideal for service that requires
frequent valve settings (throttling).
Globe valve inlet and outlet openings are arranged
in several ways to satisfy different requirements of
Figure 4-2 shows three common types of globe
valve bodies. In the straight type, the fluid inlet and
outlet openings are in line with each other. In the angle
Figure 4-2.Types of globe valve bodies.
type, the inlet and outlet openings are at an angle to
each other. An angle type of globe valve is commonly
used where a stop valve is needed at a 90-degree turn in
a line. The cross type of globe valve has three
openings, rather than two; it is frequently used in
connection with bypass lines.
Globe valves are commonly used in steam, air, oil,
and waterlines. In many boiler plants, there are surface
blow valves, bottom blow valves, boiler stops, feed
stop valves, and many guarding valves and line cutout
valves. Globe valves are also used as stop valves on the
suction side of many fireroom pumps as recirculating
valves in the fuel oil system and as throttle valves on
most fireroom auxiliary machinery. A cross-sectional
view of a globe valve is shown in figure 4-3.
The butterfly valve (fig. 4-4) in certain
applications has some advantages over gate and globe
valves. The butterfly valve is light in weight, takes up
less space than a globe valve or gate valve, is easy to
overhaul, and can be opened or closed quickly.
The design and construction of butterfly valves
may vary, but a butterfly type of disk and some means
of sealing are common to all butterfly valves.
Figure 4-3.Globe valve.