Needle valve is an important part of the instrument measurement pipeline system, and it is a valve that can accurately adjust and cut off the fluid. The valve core is a very sharp cone, which is generally used for small flow, high pressure gas or liquid. Its structure is similar to the globe valve, and its function is to open or cut off the valve for pipeline access.
1. The opening and closing part of needle valve is a sharp cone, which rotates counterclockwise when opening and clockwise when closing.
2. The internal structure is similar to that of the stop valve, both of which are low inlet and high outlet. The valve stem is driven by the handwheel.
Structure principle of needle valve
1. The needle valve with valve cover should be selected for the pipeline system and device of low-temperature medium.
2. On the pipeline system of the catalytic cracking unit of the oil refining unit, the lifting rod needle valve can be selected.
3. Needle valves shall be made of austenitic stainless steel with PTFE as the valve seat sealing ring in the devices and pipeline systems with corrosive media such as acid and alkali in the chemical system.
4. Metal to metal sealing needle valves can be selected for pipeline systems or devices of high-temperature media in metallurgical systems, power systems, petrochemical plants and urban heating systems.
5. When flow regulation is required, worm gear driven, pneumatic or electric needle valve with V-shaped opening can be selected.
6. The needle valve with full bore and full welding structure shall be used for the transmission main pipeline of oil and natural gas, the pipeline to be cleaned and the pipeline to be buried underground; For those buried on the ground, the ball valve with full bore welding connection or flange connection shall be selected.
7. Flange connected needle valve shall be selected for the transmission pipeline and storage equipment of product oil.
8. On the pipelines of urban gas and natural gas, needle valves with flange connection and internal thread connection are selected.
9. In the oxygen pipeline system of the metallurgical system, the needle valve with strict degreasing treatment and flange connection should be selected.
10. Needle valve is composed of valve body, needle cone, packing and handwheel.
Post time: Sep-28-2022