Search results
Results from the WOW.Com Content Network
A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. [1] This enables the direct control of flow rate and the consequential control of process quantities such as pressure , temperature , and liquid level.
Oxygen and MAPP gas cylinders with two-stage pressure regulators Schematic diagram of pressure reducing regulator (A) and back-pressure regulator (B). The upper diagrams show the normal state for the valves, which is normally open for pressure reducers and normally closed for back-pressure valves.
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.
Tilting-disc inconel check valve Check valve symbol on piping and instrumentation diagrams.The arrow shows the flow direction. Vertical lift check valve. 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.
Piping and instrumentation diagram of pump with storage tank. Symbols according to EN ISO 10628 and EN 62424. A more complex example of a P&ID. 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.
The hydraulic actuators respond to changes of pressure or flow and will open or close the valve. Automatic control valves do not require an external power source, meaning that the fluid pressure is enough to open and close them. Flow control valves, a type of automatic control valve, regulate fluid flow by maintaining a predetermined flow rate ...
A relief valve DN25 on cooling water pipe from heat exchanger Schematic diagram of a conventional spring-loaded pressure relief valve. A relief valve or pressure relief valve (PRV) is a type of safety valve used to control or limit the pressure in a system; excessive pressure might otherwise build up and create a process upset, instrument or equipment failure, explosion, or fire.
The MFC is fitted with a closed loop control system which is given an input signal by the operator (or an external circuit/computer) that it compares to the value from the mass flow sensor and adjusts the proportional valve accordingly to achieve the required flow. The flow rate is specified as a percentage of its calibrated full scale flow and ...