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1.Globe valves are normally installed with flow and pressure
under the disc. Always check with the manufacturer before
installing valves with flow in the other direction.Under certain
service conditions or when valves are equipped with cylinders
or electric motor actuators, there may be a cost advantage
in the designing and installing the valves with flow over
the disc. If actuators are sized for these conditions, care
must be taken to assure valves are installed correctly.
2.Threaded seat rings in valves in services with high velocity
(turbulent) flow or thermal cycling should be lock welded
to the body to avoid loosening. Please specify.
3.Conventional globe valves are suitable for most throttling
applications and will provide the greatest service life where
pipe line velocity in FT/SEC does not exceed 240 . (v is a
specific volume of flowing medium, ft.3/lb.) Prolonged throttling
at less than 10% open is not recommended due to the possibility
of excessive vibration, noise and damage to disc and seats.
Use of smaller valves or V-Port trim with lower flow capacity
may permit the valve to be open at a greater percentage, thus
avoiding damage. Continuous severe throttling applications
may require a control valve.
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