Process control parameters
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What is the relationship between design parameters and control parameters? What is the relationship between control parameters and the upper and lower alarm limits? For example, does the control range overlap with the upper and lower alarm values, or is it acceptable for the control range to be outside these alarm values, or to lie within them?
Design indicators are the theoretical values for normal operation during design, while control indicators refer to the operating parameters used in actual production; these may be the same as or different from the design parameters. The upper limit for alarms is generally set at 80% of the operating parameters, and the lower limit at 20% of those parameters
Control limits do not overlap with the alarm upper and lower limits; generally, control limits lie within those alarm limits
Are there any regulatory guidance documents?
Yes, I also want to know this question: whether the normal control parameters for the process include overreporting and underreporting. Or, overreporting and underreporting fall outside the normal control parameters of the process. What is the basis? ? ? Urgent
What is the relationship between this process alarm point and the process operating range? Currently, some organizations or higher-level groups have stipulated that a process alarm point must be present before a process interlock value.
I’m hoping that someone experienced in this group can explain whether process alarms occur within the set alarm limits or outside of them. It can’t be the case that some alarms occur within those limits while others do not, right? It would be best if there are relevant documents to support it
There are two types of measures for process emergencies: alarms and interlocks. Alarms provide visual warnings to process operators in the form of sound and light. There can be high-high alarm, high alarm, low alarm, and low-low alarm ； It can be set individually or in multiple instances, depending on the specific manufacturing process. Interlock is an emergency intervention measure for the process, and it can include low-limit interlocks and high-limit interlocks. It can be understood in this way: low interlock limit, low-low alarm, low alarm, normal operating condition, high alarm, high-high alarm, high interlock limit ▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁
There are two types of measures for process emergencies: alarms and interlocks. Alarms provide visual warnings to process operators in the form of sound and light. There can be high-high alarm, high alarm, low alarm, and low-low alarm ； It can be set individually or in multiple instances, depending on the specific manufacturing process. Interlock is an emergency intervention measure for the process, and it can include low-limit interlocks and high-limit interlocks. It can be understood in this way: low interlock limit, low-low alarm, low alarm, normal operating condition, high alarm, high-high alarm, high interlock limit ▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁▏▁▁▁▁▁▁▁▁▁▁
The general control limits should fall within the range of the design parameters, with the alarm thresholds set below these control limits. For example, to produce qualified products, a temperature of no less than 100°C is required; this 100°C value constitutes the control limit. The lower limit for pricing is then set at 110°C, so that an alarm is triggered when the temperature drops to 110°C. Operators then adjust their actions to ensure that the products remain of satisfactory quality. The difference between this pricing limit and the control range should be determined based on actual circumstances, taking into account the time needed for operators to make the necessary adjustments after receiving the alarm