What is A Needle Valve ?

- Needle valve is specialized valves used for metering fluid flow. Their use is primarily limited to small systems such as instrumentation or fuel regulation where the ability to control the flow of fluid precisely and repeatably is highly desirable. Needle valve is available in two main body configurations.

- Needle Valve, it is a gate valve style has gate (disc) is piston with screw. A Needle Valve allows precise flow regulation, suitable for low flow requirements.

Technical Needle Valve

- Product Name: Needle Valve

- Size for piping: DN3, DN4, DN5, DN6, DN8, DN10, DN15, DN20, DN25, DN32, DN40, DN50

- Pressure range: 0.6MPa - 16MPa

- Materials of Needle valve: SS 201, SS 304, SS 316 / 316L, A105, WCB, 0Cr18Ni9, 1Cr18Ni9Ti, 06Cr19Ni10, etc.

- O-ring and Gasket: Soft metal, PTFE Gasket

- Working temperature range: 250 độ C

- Media Working: Water, Oil, Gas, Acidic and alkaline media such as liquid, etc.

- Size of Needle Valve : 1 inch = DN25, 6 points =3/4=DN20, 4 points =1/2=DN15, 3 points =3/8=DN10, 2 points =1/4=DN6

Operations of Needle Valve

Operations of Needle Valve

Advantages of Angle Seat Valve

- The needle valve advantage is from the vernier effect of the ratio between the length of the needle and the diameter of the needle, or the difference in diameter between the needle and the seat. A long vertical stroke (control input) produces a very small and precise change (affects the resulting flow).

- Needle valves can also be used in vacuum systems, where precise control of gas flow is required, at low pressures, [1] such as when filling vacuum tubes filled with gas, gas lasers and other equipment. similar.

- Automatic liquid needle valve on a liquid handling system.

- Needle valves are commonly used in flow measurement applications, especially when maintaining a steady, calibrated, low flow rate for a period of time, such as idle fuel flow in a carburetor.

Defect of Angle Seat Valve

- Since the flow rate is low and many turns of the valve body are required to open or close completely, needle valves are not used for simple shut-off applications.

- Unlike ball valves or float valves. It is difficult for the needle valve to recognize the opening and closing status through the position of the handle.

- Note that the carburetor float valve (which controls the fuel level in the carburetor) is not a needle valve, although it is often described as one. It uses a blunt conical needle, but it sits on a square chair rather than a matching cone. The intention here is to get a well-defined seat between two narrow mating surfaces, creating a steady flow from only a slight buoyant pressure.

- Needle valves are also commonly used to shut off power to pressure gauges or on nozzles to shut off the supply of NH3 to the knife in anhydrous ammonia (NH3) applications.