What are the differences in usage and applications between ball valves and needle valves? l
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Ball valve: It evolved from a plug valve. It has the same 90° rotation action, but the difference is that the plug body is spherical, with a circular hole or passage running through its axis. The ratio between the sphere and the opening should be such that when the sphere rotates 90°, the entire area at the inlet and outlet should be covered by the sphere, thereby blocking the flow of fluid. Needle valve: A needle valve is a type of throttle valve with high regulation precision. The valve element is needle-shaped and moves in the direction of the water flow to change the cross-sectional area through which the fluid passes, thereby shutting off or regulating the flow rate. A needle valve is a fine-tuning valve whose plug is needle-shaped, and it is primarily used to regulate gas flow. The fine-tuning valve requires the valve opening to increase gradually, allowing for continuous and precise adjustment from closed to fully open. Pin-type valve plugs are generally made of hardened steel pins, while the valve seats are constructed from soft materials such as tin and copper. The sealing between the valve needle and the valve seat is achieved through a tight fit of their conical surfaces. The taper of the valve needle is available in two angles: 1:50 and 60, and the tapered surface must be finely ground. The sealing between the valve stem and the valve seat is achieved through a bellows. Difference between ball valves and needle valves: Needle valves can adjust the flow rate, while ball valves cannot ； The needle valve needs to be turned several times on the handle to open fully, while the ball valve only needs to be rotated 90°. The differences in appearance are more noticeable: needle valves have handwheels, while ball valves have handles. To regulate flow in liquid and gas pressure control pipelines, a needle valve should be used; to quickly shut off the flow, a ball valve should be used.
For instrumentation applications, needle valves can be used for pressure-taking valves and analysis sampling valves in clean media, while ball valves are suitable for shutting off gas supplies. In the vast majority of cases, globe valves or gate valves are chosen for one-way valves.
That’s indeed the case, but could you explain why this choice was made?
It seems that the needle valves used in factories, as well as those globe valves sold in hydraulic and pneumatic stores, are complete junk – they can’t even provide any proper sealing; no matter how tightly you turn them, it’s useless. 、
This post was last edited by Stone_HOTO on 2018-11-28 at 11:53. Needle valves are more commonly used for pressure sampling, while ball valves are more often used for pressure release or unloading – choose according to your needs
Generally, needle valves are more commonly used for the valve in front of pressure gauges. There is one prerequisite for this: there is also a root valve (gate valve or globe valve) ahead. Based on my experience, needle valves tend to break easily
I’ve learned it.* Thank you. I offer PTFE needle valves, PTFE ball valves, and PTFE globe valves made of highly corrosion-resistant and heat-resistant PTFE material; they are made from imported raw materials and come in a genuine milky white color.