When laying out a P&I diagram, when is it necessary to show the relative elevation of process connections to equipment?
Explanation
While P&I diagrams are not scale drawings, the relative vertical positioning of nozzles and equipment is crucial for certain operations. It must be shown for systems like pumps, where suction height is critical (NPSH), and for gravity-driven systems like thermosiphon reboilers and barometric legs to ensure they will function correctly.
Other questions
What is the primary distinction between a Process Flow Diagram (PFD) and a Piping and Instrument Diagram (P&ID)?
According to the ANSI/ISA 5.1-2009 symbols illustrated, what does a simple rectangular box symbol represent in the context of control valves?
Based on the ISA-5.1-1984 letter code for instrument symbols, what measured variable is indicated by the first letter 'L'?
What does a single circle symbol represent in the context of general instrument and controller symbols?
What is the operating principle of a Venturi meter used for measuring volumetric flow?
In the context of process control objectives, what is the goal related to 'Production rate'?
When drawing preliminary P&I diagrams, which of the following is a basic rule of process control to remember regarding level controllers?
In a typical level control arrangement at the base of a column using a pump, where should the control valve be placed?
How is pressure commonly controlled in a condenser by manipulating the heat-transfer area?
What is the primary purpose of cascade control?
In a material balance control scheme for a distillation column, if the bottoms product purity is the primary concern, how is control typically achieved?
What are the three basic components of an automatic trip system?
What is the international standard, based on the ISA S88 committee's work, that defines the architecture for batch process control systems?
What is the primary advantage of using microprocessor-based MIMO (multiple input-multiple output) devices in a process control system compared to conventional SISO (single input-single output) controllers?
What function is represented by the letter 'Y' when it appears as a second or subsequent letter in an instrument symbol according to ISA-5.1-1984?
How does a Distributed Control System (DCS) differ from a simple instrument panel?
What is the primary function of a Programmable Logic Controller (PLC)?
When is a bypass control typically used for a heat exchanger?
What is the primary objective of a 'temperature-pattern control' or 'dual composition control' scheme in a distillation column?
Why is it often impractical to use online composition analyzers for the primary control of distillation columns?
What is represented by a control valve symbol with an arrow pointing upwards?
Which instrument uses a differential pressure (DP) cell placed between the top and bottom of a vessel to indicate level?
According to the guide rules for developing control schemes, where should you include extra connections for instruments that may be needed for future troubleshooting?
What is a major limitation of model-based predictive control when it comes to measuring product quality?
In a simple flow control scheme for a centrifugal pump with a variable-speed drive, what does the flow controller directly manipulate?
In the instrument symbol 'TRC', what do the three letters T, R, and C represent respectively?
What is the primary drawback of a 'dual composition control' scheme for a distillation column?
What type of signal is represented by a solid line with double hash marks crossing it on a P&I diagram?
In a simple vaporizer control scheme where the feed is on flow control, how is the level in the vaporizer typically maintained?
Which of the following items is NOT expected to be identified with a number on a P&I diagram?
What is the operating principle of a pH measurement system using a glass electrode?
What does a control scheme where one flow controller's setpoint is determined by the measured flow of another stream represent?
Where should the temperature sensor for composition control in a distillation column ideally be located?
What is the primary reason that interlocks are included in a plant control system?
What type of actuator is represented by the letter 'M' in a circle on a P&I diagram?
In a control scheme for a simple liquid phase reactor, pressure is often controlled by what method?
For which of the following applications would a spill-back flow control, as shown in Figure 5.11(a), be a typical choice?
What is the primary reason that modern control systems log and archive data from plant historian databases?
According to the ISA-5.1-1984 symbol standard, what does the combination 'PT' represent?
Which of the following is a key safety objective of instrumentation and control schemes?
When is temperature control generally considered ineffective for a condenser?
According to the guide rules, what is the most responsive way to control pressure?
What type of instrument is represented by a circle with a square around it on a P&I diagram?
What is the key characteristic of a 'material balance control scheme' for a distillation column?
What is the symbol for a self-contained backpressure regulator?
Why might a designer specify a separate, dedicated trip system for a hazardous situation rather than relying on the main process control system's alarms?
In a batch distillation control scheme as shown in Figure 5.18, how is the product composition often inferred for control purposes?
What type of control element is typically used to manipulate the overall plant material balance?
What is the primary distinguishing feature of a shared display device with software alarms, as shown in the symbol in Figure 5.6?