As pressure rises on plants to improve productivity and equipment reliability levels, seals and gaskets are being called upon to provide even better performance. Their challenge no longer is simply to prevent leaks but also to play an important role in the life-cycle management of the plant.
In this installment of Ask The Experts, noted process control authority and CONTROL Columnist Béla Lipták and his cadre of automation experts answer a readers question regarding control valves for slurry services.
There are two main drivers for partial stroking of valves in safety systems: the desire to extend manual test intervals to as long as possible; and to reduce the amount of redundant hardware required for higher safety integrity levels. Like most things in life, it all boils down to one thing: trying to save money.