Definition and core characteristics of straight-through globe valve
Straight-through globe valve (straight-through globe valve) is a forced sealing valve with inlet and outlet channels arranged in a straight line of 180 degrees. Its core function is to realize fluid on-off control through the forced fit of the valve disc and the valve seat, and is usually not used for flow regulation.
1. Structural features
Channel design
The inlet and outlet are located on the same axis, and the medium flow direction has no angle change, which is suitable for straight pipeline layout.
The valve body flow channel is vertically symmetrical, with large internal resistance, and it is easy to form medium vortex.
Key components
Valve disc and valve seat: The sealing surface is often a plane or a cone, and it is necessary to apply pressure through the valve stem to force it to be pressed (closing pressure ≥ nominal pressure); Valve stem structure: lifting rod type (handwheel fixed) or lifting and rotating rod type (handwheel and valve stem rotate synchronously), the valve stem diameter must meet the bending strength requirements; Material: The valve body is mostly made of cast steel (WCB) and stainless steel (304/316), and chrome-molybdenum steel can be selected for high-temperature scenes.
2. Working Principle
The valve stem is driven downward by rotating the handwheel, forcing the valve disc to fit closely with the valve seat to cut off the medium; when opening, the valve stem is lifted in the opposite direction, and the medium passes along the straight flow channel. Because the medium flows from the bottom of the valve disc into the valve cavity, it is necessary to overcome the higher medium pressure when closing, and the operating torque is large.
3. Applications
General vertical pipeline: suitable for on-off control of liquid and gas media, especially suitable for vertical installation of pipelines; Medium and low pressure systems: the commonly used nominal pressure range is PN16~PN40, suitable for conventional working conditions such as chemical industry and water treatment; Non-corrosive media: ordinary material models can handle water, steam, oil and other media, and highly corrosive fluids should be avoided.
