I have written often about how we should establish safe upper and lower limits for our covered process(s). (SAFTENG members can read Establishing Safe Upper and Lower Limits) One mistake we have discussed is related to safe upper pressures and its relationship to the MAWP of process vessels. We continue to see errors in such that a vessel with an MAWP of 300 psi, will have a Relief Device with a set point at 300 psi and therefore the facility sets their safe upper limit at 300 psi. This is just fundamentally wrong on several fronts, but I was so impressed with Parker Refrigerating Specialties Division spec sheet “advice” regarding this error…