What is the difference between needle valve and ball valve?
What is the difference between needle valve and ball valve?
Needle valve is an important part of measuring pipeline system. There are mainly globe valves and ball valves, which are generally used to open or cut off pipeline access. Needle valve core is a very sharp cone, needle valve shape than other types of valve pressure capacity, better sealing, so generally used for small flow, high pressure gas or liquid medium sealing.
The opening and closing parts of the ball valve are driven by the valve stem and rotate around the axis of the ball valve, which can be used for fluid regulation and control. Ball valve in the pipeline is mainly used to cut off, distribute and change the flow direction of medium, which is suitable for switch and cut-off valve.
Needle valve is a kind of throttle valve, which has high regulation precision. The valve is needle shaped and moves along the flow direction to change the cross-sectional area of the flow, so as to cut off or regulate the flow. Needle valve is a kind of fine-tuning valve, its plug is needle shaped, mainly used to adjust the throttle flow. The fine tuning valve requires that the opening of the valve port gradually increases, and the maximum continuous fine adjustment can be made from closing to opening. Needle plug is usually made of quenched steel needle, while the valve seat is made of soft materials such as tin and copper. The seal between needle type valve and valve seat depends on its conical surface. The taper of valve needle is 50 degree and 60 degree, and the cone surface needs fine grinding. The sealing between valve stem and valve seat is realized by bellows.
Difference between ball valve and needle valve:
The needle valve can adjust the flow rate, but the ball valve can't adjust the flow rate; when the needle valve is fully opened, it needs to turn the handle several times, while the ball valve only needs to rotate 90 degrees.
In appearance, the difference is more obvious, needle valve has hand wheel, ball valve has handle.
In liquid and air pressure control pipeline, needle valve is selected if flow is to be adjusted, and ball valve is selected if flow is cut off quickly.
It can be seen that there are great differences between needle valve and ball valve in application scope and function.
