Tuesday, September 8, 2015

Severe Service Ball Valves Meet Toughest Application Challenges

Industrial ball valve for severe service - section view
Severe Service Ball Valve Section View
Courtesy Mogas Industries
Industrial process control, as a field of endeavor, can expose an engineer to instances where their design input can have very significant impact on the financial prospects of their employer, even the safety and well being of the public residing near company facilities. "Getting things right the first time" is much more than a motivating slogan on a poster tacked to the wall in the corridor outside the engineering department. It is what our society demands of engineers. Fortunately, there are engineers that embrace the role of making sure things go as planned. They work as process engineers and also as designers of the componentry and equipment used to implement complex and potentially dangerous processes.

I have written about the positive and potentially not so positive attributes of ball valves for industrial process control applications. In that recent blog article, I mentioned that ...

"There may be particular ball valve variants that overcome potential shortcomings listed in this article".

Ball valves designed for severe service are an example of a manufacturer specifically designing ball valves to not only overcome some potential shortcomings of the valve type, but to extend the performance ratings into areas that accommodate some of the most demanding applications in the process control field.

What constitutes severe service?


  • Extreme temperatures
  • High pressures
  • Abrasive particulates
  • Acidic products
  • Heavy solids build up
  • Critical plant safety
  • Large pressure differentials
  • Velocity control
  • Noise control


Extended or enhanced features of severe service ball valves include:


  • Floating or trunnion mounted ball design with straight through bore path that protects the sealing surfaces.
  • Wide seat sealing surface with matched ball and seat sets that provide total sealing contact for reliable isolation. The greater sealing contact area withstands minor scratches and abrasions.
  • Independent replaceable seats to minimize repair and maintenance costs.
  • Pressure energized sealing, with seat springs that maintain a constant sealing contact between the ball and seats. Metal seats wipe the ball sealing surface clean during every operation.
  • Blowout proof one piece oversized stem design meets stringent industrial safety standards and withstands maximum working pressures and extreme service torques.
  • Dual-guided stem design employs pressure energized inner stem seals as a thrust bearing and lower stem guide. The valve stem bushing serves as the upper stem guide to eliminate lateral movement of the stem and prevent media migration and fugitive emissions.
  • Greater body wall thickness, with forged body and end connections for longest service life.
  • A heavy duty operator mounting flange, to provide structural support for the valve operator, is machined after attachment to assure precise stem alignment.
Application specific features, such as seat designs, live loaded packing, body gaskets, coatings, liners, purge ports, end connections, and special materials are also available to customize these severe service valves to meet extreme application requirements. The presentation below provides schematic and illustrated examples where severe service valves are applied and provides additional detail about the special features incorporated in the design of severe service ball valves. For all your control or isolation valve projects, whether in the conceptual, planning or implementation stage, consult a valve specialist. Merge your grasp of the process and its requirements with the product knowledge and application experience of a specialist and produce a solidly positive project outcome.