Needle valve is a valve that can be adjusted and has a wide range of applications, such as the cutting distance used for flame cutting, and the knob for adjusting flame temperature is a needle valve. Instrument needle valves are an important component of the instrument measurement pipeline system, mainly including globe valves and ball valves. Their functions are to open or cut off pipeline paths. The valve core of a needle valve is a sharp cone that inserts into the valve seat like a needle, hence its name.

In general, the opening and closing directions of needle type globe valves are clockwise for closing and counterclockwise for opening. In special cases, there will be special markings. Switches are generally in the shape of handles. If the handle and valve are in the same direction, they are fully open. If there is a handwheel, rotating it in the direction of the right thumb is open, and vice versa is closed. If there is a handle along the pipeline, it is open, and if the handle is at a 90 degree angle with the pipeline, it is closed.

Installation precautions for needle type globe valves:

1. The installation position, height, and direction of inlet and outlet must meet the design requirements. It should be noted that the direction of medium flow should be consistent with the arrow direction marked on the valve body, and the connection should be firm and tight.

2. Visual inspection must be conducted before valve installation, and the nameplate of the valve should comply with the current GB standard "General Valve Markings" GB 12220. For valves with a working pressure greater than 1.0 MPa and a shut-off effect on the main pipe, strength and tightness tests should be conducted before installation, and they can only be used after passing the test. During the strength test, the test pressure shall be 1.5 times the nominal pressure, and the duration shall not be less than 5 minutes. The valve shell and packing shall be deemed qualified if there is no leakage. During the tightness test, the test pressure shall be 1.1 times the nominal pressure; The duration of the test meets the requirements of GB 50243.

The function of any valve is to cut off fluid According to the different valve cores, they can be divided into globe valves, gate valves, plug valves, ball valves, butterfly valves, needle valves, and so on. Needle valves can withstand greater pressure and have better sealing performance than other types of valves, so they are generally used for sealing gas or liquid media with smaller flow rates and higher pressure. Needle valves are suitable for use with pressure gauges. Generally, needle valves are made of threaded connections. Nominal pressure: PN2.5 PN4 PN6.4 PN16 PN32Mpa Nominal diameter: DN5~DN25 Applicable medium: various non corrosive or corrosive media such as oil, water, gas Applicable temperature: -20 ℃~+440 ℃ -70 ℃~-240 ℃ ≤ 540 ℃ ≤ 570 ℃ Manufacturing materials: 20 #, 1Cr18Ni9Ti, 304, 316, 316L, 12Cr1Mov, etc