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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