Globe Valve
opening and closing parts are plug-shaped disc, the sealing surface is
flat or conical, and the disc moves linearly along the center line of
the fluid, the
movement forms of the valve stem include the lifting rod type (the
valve stem rises and falls, but the hand wheel does not rise and falls),
and the lifting rotary rod type (the hand wheel and the valve stem rise
and fall together, and the nut is set on the valve body). Globe valve is only suitable for full open and full close, not allowed to adjust and throttle.
Globe
valve is a forced seal valve, so when the valve is closed, pressure
must be applied to the disc to force the sealing surface not to leak, when
the medium enters the flow channel from below the valve disc, the
resistance to be overcome by the operating force is the friction force
between the valve stem and packing and the thrust force generated by the
medium pressure. The force to close the valve is larger than that to
open the valve, so the diameter of the valve stem should be larger,
otherwise the valve stem will be bent. In recent years, since the
appearance of self sealing valve, the medium flow direction of the stop
valve has changed from the top of the disc to the valve chamber. Under
the action of medium pressure, the force to close the valve is small,
while the force to open the valve is large, and the diameter of the stem
can be reduced accordingly. At the same time, under the action of
medium, this type of valve sealing is also tight.
When the globe
valve is opened, when the opening height of the disc is 25% - 30% of
the nominal diameter, the flow has reached the maximum, indicating that
the valve has reached the full open position. Therefore, the full open
position of the globe valve should be determined by the stroke of the
disc.
Advantages of globe valve:
1. Simple structure, convenient manufacture and maintenance.
2. The working stroke is small and the opening and closing time is short.
3. Good sealing performance, small friction force between sealing surfaces and long service life.
Installation and maintenance of globe valve:
1. The hand wheel and handle operated globe valve can be installed at any position of the pipeline.
2. Hand wheel, handle and moving mechanism are not allowed to be used for lifting.
3. The flow direction of the medium should be consistent with the arrow direction shown on the valve body.
According to the position of stem thread, the types of globe valve are divided into external thread type and internal thread type. According to the flow direction of the medium, there are straight through type, direct current type and angle type. According to the sealing form of globe valve, there are packing seal globe valve and bellows seal globe valve.
STAVAL provides high performance globe valve products, including API globe valve, DIN globe valve, ANSI bellow seal globe valve, Angle globe valve, Y type globe valve, and Pressure seal globe valve etc.
Good Service, Better Price, Best Quality by Xiamen Stavalve Valve Technology Co.,Ltd
taggar :