Rotary Valve Uses Special Seal Technology
Emerson Process Management introduces the Fisher POSI-SEAL A81 rotary valve. Tight shutoff and the long seal life capability of the A81 is said to make it ideal for on/off applications.
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 highly suited to automated on-off, quarter-turn performance and is typically used with the FieldQ rack-and-pinion actuator. The valve is available to ship in two weeks to meet day-to-day and emergency needs. The new rotary valve can be used in most process on/off applications; it is said to install easily in either a horizontal or vertical orientation with no detriment to performance or cycle life.