Globe Valves: Maintenance, Applications and Uses
What is a Globe Valve?
Globe valves (GV) are mostly in-demand
in various Industries. A common use of Globe Valve is to control the flow of
fluid in a pipeline and adjust the Gaps between the Globe Shaped Plug
and the Ring Seat. It consists of a movable disk-type element and a ring seat
in a spherical body. When Compared to other Valves, Globe
Valve doesn’t Leak Much because of the Right Contact between the Disc and
the Ring. The Disc available on a globe valve can be removed from a flow path.
Globe Valves opening and closing is done by an actuator
because the plug of a globe valve is connected to a stem that is operated by a
screw. Basically, Globe valves are designed with a stem that can move up and
down to regulate the flow inside the valve. Seats of this valve are designed in
a plane parallel or inclined to the line of the flow. These types of valves are
most commonly used to throttle, open or close flow in a piping system.
Parts of a Globe Valve:
Main Components of every product is its body, let us
now look at the parts of a Globe Valve which consists of the following
·
Body
·
Disc
·
Body Seat Ring
·
Lock Washer
·
Disc Stem Ring
·
Union Bonnet Ring
·
Bonnet
·
Stuffing Box
·
Packing
·
Gland
·
Packing Nut
·
Stem
·
Wheel Nut
·
Wheel
Advantages of Globe valves:
·
The opening-closing time of a globe valve is
shorter.
·
Globe Valve (GV) contain positive shut-off
·
Provides Good throttling Capability.
·
Doesn’t Leak much as compared to other valves
·
Has a Shorter Stroke
·
Easy to machine or resurface the seats.
·
Available in Different Types with each offering
unique Capabilities.
·
The body ring seating surface process is easier.
Disadvantages of Globe Valves:
·
Non-Benefits a Globe Valve has
it that it requires a great force or a large actuator to seat the Valve
·
Higher Flow Pressure and to close globe valves
under high pressure, it requires a larger amount of force or an actuator with a
large torque
·
Other Disadvantages of a Globe Valves is that it
has a High-Pressure Drop
Maintenance of Globe Valves
The packing of the Globe valve is subjected to
depreciation i.e., wear and tear and thus needs to be changed after some time
as the sealing quality will reduce. However, continuous opening and closing of
the valve leads to damage to the metal of the valve seat. Lapping paste is
applied to the seat to make the surface smooth and remove any clearances and
also helps in damaging the product.
Applications & Uses of Globe Valve:
Globe valve can be used as a non-return valve as it is
used in applications where variable pressure is required in the pipeline such
as emergency line etc. The type of valve where the disc is not attached to the
spindle is called screw-down non-return valve. This type of valves is used for
preventing back flooding. The type of valve wherein the disc is attached to the
spindle is known as the screw lift type valve.
Applications of GV are as Follows:
·
Applied in cooling water systems where the flow
needs to be regulated
·
Used in Fuel oil system where the flow is
regulated and leak tightness is of importance
·
Chemical Industries to provide a smooth flow of
fluid, materials, slurries
·
Petrochemical Industries
·
Turbine seals and drains
·
Paper Manufacturing Industries
·
Shipping Industries
·
Steel Factories
·
Turbine lube oil system and others
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