Introduction to needle valve
The needle valve is a fine-tuning valve whose valve plug is needle-shaped and is mainly used to adjust the air flow. The fine-tuning valve requires the opening of the valve port to gradually increase, and it can be continuously and finely adjusted from closed to maximum. The needle valve plug can achieve this function. The needle valve plug is generally made of hardened steel long needle, and the valve seat is made of soft materials such as tin and copper. The sealing between the valve needle and the valve seat is achieved by the close fit of the conical surface. The taper of the valve needle has two taper angles of 1:50 and 60, and the taper surface must be finely ground. The seal between the valve stem and the valve seat is realized by a bellows.