Since this tracing is only for freeze-protection, you may want to add a thermostatic control valve (Ogontz makes one) on steam supply to tracing. This will reduce steam consumption when ambient temeberature is above freezing. That is better than relying on someone to rember to turn on the...
Dcasto's reply pretty much sums it up. I'd just mention that cladding or lining a vessel requires additional fabrication. Vessel size can play into the decision. For small vessels like vapor-liquid separators, it is often more economical to fabricate from solid alloy rather than clad or line a...
I am hoping to use different symbols rather than additional text. Instrument tag prefixes need to follow ISA standards. Lengthening the instrument tag either in the prefix or suffix to designate control system makes it difficult to fit within symbols.
I have thought about using a boxed diamond...
I read a good exchange on functionality and merits of DCS vs. PLC (see thread698-161284). Now that DCS functional often includes logical controls, instrumented process trips (i.e. interlocks) can be easily programmed into most DCS systems. However, as noted in referenced threads, critical trip...
