Instrumentation Loop Diagrams
The Loop diagram sometimes called a loop sheet. Loop Diagrams Here we are discussing for the compressor surge control system (loop number 42): Here we see that the P&ID didn’t…
DC Circuits Multiple Choice Questions
DC Circuits Multiple Choice Questions Question 1 Determine the voltage dropped across resistor R3 in this circuit: (A) 7.5 volts (B) 3.0 volts (C) 6.6 volts (D) 15 volts (E)…
AC Circuits Multiple Choice Questions
AC Circuits Multiple Choice Questions Question 1 What will happen to the current in this circuit as frequency increases? (A) Current will remain the same (B) Cannot tell – not…
Instrumentation Functional diagrams
Functional diagrams are sometimes referred to as SAMA diagrams in honor of the organization responsible for their standardization, the Scientific Apparatus Makers Association. This organization has been succeeded by the…
Industrial Automation Communication Protocols
How do instruments and controllers communicate in a process control? Has it ever came in your mind how instruments and controllers communicate? We know for a fact that communication may…
Directional Control Valves Working Principle
Directional control valves perform only three functions: stop fluid flow allow fluid flow, and change direction of fluid flow. These three functions usually operate in combination. Classification of Directional Control Valves…
Difference between Intrinsically Safe and Flameproof Equipment ?
If a fault develops in a piece of electrical or electronic equipment located in an area where flammable gases are present the fault could cause heat or sparks sufficient to…
Impact of Flow Meter Accuracy
In flow meter, a number of terms are important to consider, which include Repeatability, Uncertainty, Accuracy, and Turndown.
What is a Flange Gasket ?
What is a Flange Gasket  ? Flange gaskets are used to create a static seal between two flanges faces, at various operating conditions, with varied pressure and temperature ratings. A…
Effect of Differential Pressure on Control Valve Lift
The air fed into the diaphragm chamber is the control signal from the pneumatic controller. The most widely used signal air pressure is 0.2 bar to 1 bar. Consider a…
