Search results
Results From The WOW.Com Content Network
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. [1] Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various ...
A piping and instrumentation diagram (P&ID) is defined as follows: A diagram which shows the interconnection of process equipment and the instrumentation used to control the process. In the process industry, a standard set of symbols is used to prepare drawings of processes. The instrument symbols used in these drawings are generally based on ...
A dual check backflow preventer is similar to a double check valve in operation. It has two independent spring-loaded check valves. However, dual check valves usually do not include shutoff valves, may or may not be equipped with test cocks or ports, and is generally less reliable than a double check valve. [4]
The direction control valve is used to control the direction of flow of compressed air. They are usually classified into normally open (NO) and normally closed (NC) valves. The normally open valves will permit flow from the inlet port of the valve to the outlet port, normally the flow will be cut by changing the position of the valve.
The most common final control element in the process control industries is the control valve. The control valve manipulates a flowing fluid, such as gas, steam, water, or chemical compounds, to compensate for the load disturbance and keep the regulated process variable as close as possible to the desired set point. [ 1]
Hydraulic analogy. Analogy between a hydraulic circuit (left) and an electronic circuit (right). Electronic-hydraulic analogies are the representation of electronic circuits by hydraulic circuits. Since electric current is invisible and the processes in play in electronics are often difficult to demonstrate, the various electronic components ...
For example, a K v calculation of 4.5 m 3 /h would most likely lead to the selection of a valve with a K v = 6.3 m 3 /h. This means the valve is capable of delivering 40% more flow than required. As pressure increases in our variable flow system, our valve will deliver this extra pressure flow. This excess flow will cause the temperature to ...
The one-line diagram has its largest application in power flow studies. Electrical elements such as circuit breakers, transformers, capacitors, bus bars, and conductors are shown by standardized schematic symbols. [ 2] Instead of representing each of three phases with a separate line or terminal, only one conductor is represented.