What is typical for sending HOA switch position status to a PLC for garden variety process control?
One signal & one PLC input for explicit status of each of the three positions, or two (Hand/Run and Auto) with Off being implied by the state of the other two? I'm thinking false status via wire...
Thank you George!
a) What would the vapor space H2S concentration in this vessel be in the proposed service? Cannot tell from this statement that 4 lb/min of H2S is generated.
- Process engineer noted that 4 lb/min of H2S is generated but didn’t note the concentration. Will ask.
b) You say...
Thanks for the input everybody. You've given me a number of specific areas to investigate (which I shall pursue). The overarching take-away for me, though, is that we need the guidance of a firm experienced this sort of evaluation. There are many angles to consider. I had a little bit of HAZOP...
A client wishes (to their credit only if totally acceptable from H&S perspectives) to re-purpose a 6000 gallon, U-Stamped pressure vessel for use in a process which will generate about 4 lbs/min of H2S in the head space. IDLH is 100 ppm; a small leak would have serious H&S consequences. We have...
I meant to say near cryogenic temps, which on reflection is an artifact of previous thoughts that the process air might be -50F or so. In any event this is nothing but cold air - process air, not IA and no serious attempt will be made to dry it. Once it's in the pipes it could get as cold as -20...
I need advice from folks who know more about this than I do; sorry I have to be so vague.
Question: What material should be used for this service, CS or Stainless are the only options for various reasons including -20F operational temps and plant prohibitions. It’s a 4” compressed air process...