Abstract: A sealing arrangement for a valve or shaft is disclosed which is designed to respond to movements of a rotatable element in a particular manner and to increase sealing pressure with increasing fluid pressure. The seal undergoes a radial compressive type movement as the pressure within a vessel housing increases between opposed sealing sleeves and this causes an increase in the sealing pressure. This predetermined movement of the seal creates a spring bias in the seal, urging the seal to return to the original, less stressed condition. Preferably, the seal is of a composite structure and a particular component of the intermediate wall section creates this spring bias. This structure has improved operating characteristics and accommodates a wider range of resilient materials to be used for the sealing washer.

Abstract: A sealing sleeve for a gate valve is disclosed which is designed to respond to movements of the gate of the valve in a particular manner. The seal undergoes an axial compressive type movement as the gate is moved between opposed sealing sleeves and this causes a predetermined radially inward buckling of an intermediate wall section of the sealing sleeve. This predetermined buckling creates a spring bias in the sleeve, urging the sleeve to return to the original, less stressed condition. Preferably, the sleeve is of a composite structure and a particular component of the intermediate wall section creates this spring bias. This structure has improved operating characteristics and accommodates a wider range of resilient materials to be used for the sealing sleeve.

Abstract: A packingless gate valve comprises a housing having two opposed resilient sleeve units that compressibly engage end to end in the valve open condition and engage opposite sides of the gate in the valve closed condition. Each sleeve unit is a resilient annular body formed at one end with an axially projecting seal lip near the inner periphery and has a stiffener ring enclosed adjacent the outer periphery at the one end. An integral gasket forming flange is formed on the other end of the sleeve body.