What
is a Lift Check Valve ?
A
lift check valve is self actuated one-way valve (NRV-non-return valve) which allows flow of fluid in
one direction through lift of valve disc. Lift type check valve is commonly
used in piping systems in which globe valves are being used as a flow control
valve. They have similar seating arrangements as globe valves. Lift check
valves are suitable for installation in horizontal or vertical lines with
upward flow.
Lift
type Check Valve How it Works?
Construction
of lift check valve is similar to globe type valve. As the flow enters,
the disk or ball is raised within guides from the seat by the pressure of the
upward flow. When the flow stops or reverses, the disk or ball is forced onto
the seat of the valve by both the backflow and gravity.Lift type check valves are available in three body patterns: horizontal, angle, and
vertical.
Point
to remember: Flow to lift check valves
must always enter below the seat.
Applications
of Lift Check Valves
They
are recommended for use with steam, air, gas, water, and on vapor lines with
high flow velocities.
Some types of lift check valves may be installed horizontally. In this design,
the ball is suspended
by a system of guide ribs. This type of check valve design is generally
employed in plastic
check valves.
The seats of metallic body lift check valves are either integral
with the body or contain renewable seat rings. Disk construction is similar to
the disk construction of globe valves
with either metal or composition disks. Metal disk and seat valves can be
reground using the same techniques as is used for globe valves.
Must read : Swing Check valves
