Emerson's Fisher POSI-SEAL A81 rotary valve ensures shutoff against maximum rated pressure drop
Emerson Process Management introduces the Fisher POSI-SEAL A81 rotary valve. Complete shutoff 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, thereby reducing seal wear. Interchangeable sealing technology allows the A81 valve body to accept both soft and metal seals. The POSI-SEAL valve is suited to automated on-off, quarter-turn performance and is typically used with the FieldQ rack-and-pinion actuator. The rotary valve can be used in most process on/off applications; it installs easily in either a horizontal or vertical orientation with no detriment to performance or cycle life.