Pole position
Although control valve, actuator and positioner technologies develop only relatively slowly, there have been advances that offer practical, diagnostic and cost/benefit issues. Brian Tinham reports
Open & shut case
You'll have heard it said more times than you probably care to remember that variance is the bane of manufacturing - and the same is true in the process sector, the utilities and so on. Why? Because it leads to all sorts of problems, ranging from quality issues to yield reductions, rework, excessive energy use, maintenance loading? The list goes on.
Opening up on control valves
There are three key steps to ensuring that control valves don't cause process plant instability. Mark Perry explains the problems and their solutions
Testing safety valves
Late in 2006, an RSA (Royal & SunAlliance) engineer surveyor was involved in the testing of safety valves at a coal-fired power station on a boiler return service. After testing was complete, a major failure occurred on the plant. The engineer surveyor, the station engineer and an engineer from the safety valve test company were enveloped in a huge steam cloud. Unfortunately, the engineer surveyor and safety valve test engineer were seriously hurt.
Control Revisited
Control valves, actuators and positioners aren't renowned for rapid technological development, but advances are changing the shape of best practice. Brian Tinham reports