Pilot operated safety valve,newly-structured, is mainly applied to such trades as petroleum & nat-ural gas, chemistry, electric, meta-llurgy & burning gas. It is the best super-pressure protecting equipment on press equipment, container, or pipeline, It is mainly characterized by shifting direct function of spring to indirect function of guide valve. What's more, main valve, applying for sleeve piston & double sealed seat, is characterized by high pre-cision of action, good recycling function, fast turning back to seat, ability to high-pressure leaking, long working time & security, toge-ther with read-justment on line, aucomatic turning back to seat after leaking again and again, tight closure, operating and main-taining conve-nience.
