VALVE WIDE SHUTPosi-Seal A81 rotary valve features tight shut-off and long seal life capability, making it ideal for on/off applications. Complete shut-off is made possible by the pressure-assisting action of the valve seal ring. The opening and closing path of the eccentric valve disk minimizes contact with the seal ring, reducing seal wear. Interchangeable sealing technology allows the A81 valve body to accept both soft and metal seals.