The present invention relates to the field of valve technology, and proposes a pressure protection
cut-off valve, comprising a valve body, a
valve seat fixed to the top of the valve body, a
hand plate rotatably arranged on the top of the
valve seat, a main
valve stem fixed to the bottom of the
hand plate and threadedly connected to the
valve seat, and a valve core arranged at the bottom of the main
valve stem, wherein the bottom of the main
valve stem is provided with a secondary valve stem capable of vertical telescopic sliding, the valve core is located at the end of the secondary valve stem, and the valve core is filled with a fluid for synchronously responding to the pressure change in the valve body; in the present invention, when the pressure in the valve cavity exceeds the set value, the
elastic membrane contracts due to the pressure, and then the fluid in the
liquid storage cavity acts on the air control component, which is then fed back to the
actuator, and the secondary valve stem is driven by the
actuator to slide downward relative to the main valve stem, thereby realizing pressure protection of the valve body. Compared with the prior art, the present invention adopts a
layout form in which the flow and the medium in the valve body are separated, which solves the problem that the operation in the prior art is relatively complicated and there is a risk of medium leakage.