Recent content by Integrator

Is this not expected behaviour, based on how a large GT works? It is a thermal cycle, if exit temp remains the same and inlet temp drops, difference of the inlet and outlet temp increases, and more energy is available from the cycle. On some large GTs inlet cooling and/or avoidance of warming...

In rare cases, and I came across one the other day, you can achieve a SIL 3 with a single instrument. In this case it was a Durag flame detector, with a SFF > 99%, due to the extensive self testing and diagnostics built in. Only time I have ever seen this though, but it can happen.

Yeah but if you go with a Pilz, for example, right relay has a serial ink capability, usually modbus, you save some wiring and your info is better

Depends, are you trying manage drawings (presentation), or information? If you care more about the information you really need use a SIM - System Information Model, where there is a single source of truth for all "facts", but it may be presented in different ways. We use a SIM for a large...

You could drive the valve directly off the level, with some clever spanning and then run the pump off the PID, being careful of relative timing so the system would not "chase it's tail". It would be some messing around, lack robustness and be confusing to anyone else that came along if their...

SS1 - Safe Stop 1, SSL - Safe Speed Limiting, or one of the variety of safety stopping modes in the ISO standard, depending on your exact application. The most well known being STO, Safe Torque Off. Most manufacturers have a VSD offering that can do more than the basic STO if you are prepared...

Yeah, this is why I favor a safety PLC system for all safety devices and then serial into it for status on the PCS/DCS.

Beware, if SIL calcs are being done the interposing relays can be quite punitive to the outcome. Also, depending if you are in the same room or not, sometimes the line monitoring is desired to be preserved (it won't pass thru the relays) and you need special relays for this, last lot I bought...

If you had read and understood what I wrote, then you might consider that just earthing the cable at both ends is not the answer, depending on the return path for earth. Next step could be to run the parallel earth conductors out with the cables to provide a good earth at the far end, but also...

Hi This is now not the current best practice, due to the increasing prevalence of high-frequency noise in industrial plant. The earthing of the screen/shield at one end turns the shield into an antenna, and the frequencies at which the characteristic impedance start making this effect...

This can be done, but only part automated so usually as a special case, not a general case, so you need to have a job that warrants the time and expense to tailor a solution.

First thing here is you mention 61511, so is it a safety system or a DCS? If it is a safety system there are lots of reasons this approach might be taken, one being the requirement for competencies to managed and maybe the client does not believe the vendor has these competencies and wishes to...