The invention provides a valve rod sealing type closed backpressure adjusting type steam security valve which comprises a
valve seat, a valve body and a valve cover. An inlet in the lower portion of the valve body is connected with a protected
pressure system through a
flange, the valve cover is arranged on the upper portion of the valve body, a valve bonnet is arranged above the valve cover, a spring is arranged inside the valve cover, the valve rod and a clamping ring penetrate through a pressing ring, the pressing ring and the clamping ring form a sealing structure, and a lower adjusting ring and an upper adjusting ring are arranged inside the valve body. The valve rod sealing type closed backpressure adjusting type steam security valve has good
valve seat sealing performance, motion performance and adjusting performance on the working condition of high temperature and
high pressure steam, and does not pollute the external environment. The design of the valve rod sealing type structure, the closed valve body and the closed backpressure adjusting mechanism meets the requirement of minimal
overpressure performance parameters, avoids medium leakage, and meets the actual demands of
energy conservation, emission reduction and
environmental protection.