This invention discloses a combined
safety valve core structure with
pilot function and its usage method, relating to the field of
safety valve technology. The main valve core is slidably and sealed to the inner wall of the valve body, while a secondary valve core is slidably and sealed to the central through-hole. A lower spring is sleeved around the secondary valve core. A main valve core seat is located at the bottom of the valve body. A pressure chamber is formed between the upper end face of the main valve core and the top of the inner wall of the valve body. The bottom medium inlet of the valve body is connected to the pressure chamber via a
branch pipe. An upper spring is located within the pressure chamber, and a secondary valve core seat is located at the connection between the
branch pipe and the top of the valve body. This invention achieves a synergistic effect of "secondary valve core
pilot triggering and main valve core
rapid response" through the coaxial nesting design of the main and secondary valve cores, combined with a
dynamic balance mechanism between the upper and lower spring forces and the
medium pressure. This invention possesses the
rapid response characteristics of a direct-start
safety valve, while also having the advantages of a
pilot-operated safety valve, such as good sealing performance, pilot characteristics, and minimal
impact from
back pressure.