Gas pressure regulator
The gas pressure regulator or gas regulator or the gas pressure regulator ( GDR ) (see EN 334) is used to provide a defined pressure of a gas . Note the differences in the gas operating pressure .
basic forms
Indirectly acting (working with auxiliary energy)
Gas pressure regulators in complex form ( gas pressure regulating systems / combined gas pressure regulating and measuring systems) are e.g. B. used to regulate the pressure in the natural gas network . Natural gas comes out of the earth at high pressure and is distributed in a pipe network with regulated pressure.
Direct acting (working without auxiliary energy)
Smaller gas pressure regulators for lower outlet pressures are usually designed in such a way that they do not require any external auxiliary energy (e.g. with electrical current) or from the inlet pressure chamber (direct-acting devices).
Such smaller regulators, e.g. As for camping gas or other pressure gas cylinders are also known as pressure reducer or cylinder regulators known.
The gas flow is interrupted or throttled by a control valve . Interferences affecting the output pressure, such as fluctuating decrease volume flow and pressure changes in the input of a pressure regulator, are compensated for by more opening or closing of the valve in the sense of an adjustment of the actual value (output pressure) to the setpoint (control process, as opposed to a control process) . If the outlet pressure increases, the valve has to close more, if it falls, it has to open further.
The setpoint is usually measured using a comparator membrane that controls the valve (force = pressure × effective area). The output pressure (actual value, pressure force of the comparator) acts on one side, and an adjustable spring force (setpoint value) acts on the other side. The valve is controlled by the continuous comparison of the setpoint value and the actual value, and the outlet pressure is regulated via its opening position so that the actual value is equal to the specified setpoint value. Since the pressure regulators are usually equipped with setpoint springs for setting the required outlet pressure, depending on the function, depending on the opening position of the valve, there is a more or less high permanent pressure deviation of the actual value relative to the specified setpoint (proportional or P deviation ).
variants
- With compensating diaphragm: force compensation of the pressure forces (inlet pressure and outlet pressure) on the valve surface that would otherwise lead to an error
- Inlet pressure control, inlet pressure control: Fluctuating inlet pressures (disturbance variable) are initially regulated to an inlet pressure, so the disturbance variable "inlet pressure" is largely eliminated.
- Differential pressure regulation : The differential pressure regulation ( orifice regulation ) is used for flow regulation (standard flow regulation or operational flow limitation as gas meter protection ).
See also
- Safety devices
- Low gas level protection (GMS)
- Gas flow monitor (GS)
- Safety relief valve (SBV)
- Safety shut-off valve (SAV)