Pressure reducers are used very generally to reduce the pressure of a fluid (liquid or gaseous). Normally, they are installed in a pipe conduit, with the result that a relatively high pressure prevails at the high-pressure inlet but a relatively low pressure prevails at the low-pressure outlet. For example, the pressure in a water conduit or the pressure from a compressed air or gas cylinder can be reduced to a desired level by means of a pressure reducer or pressure regulator of the type stated at the outset.
For this purpose, DE 1 523 323 A1, for example, discloses a two-stage pilot arrangement for a high-pressure gas regulator, in particular for high inlet pressures and high pressure drops. This regulator has a main valve with a spring-loaded valve plunger for adjusting the pressure drop between a high-pressure inlet and a low-pressure outlet and a device for producing a pilot loading pressure.
DE 10 204 746 A1 relates to a gas pressure regulator for regulating a gas pressure, especially in a gas-powered vehicle, and includes a housing with an inlet and outlet and a low-pressure chamber arranged in the flow path between the inlet and outlet. A valve arrangement having a closing element can open or close a sealing seat for regulating the gas pressure to a greater or lesser extent. Arranged in the low-pressure chamber is a diaphragm, which is subjected to the pressure from the low-pressure chamber. A first device is used to preload the diaphragm. Moreover, at least one further device is provided for the purpose of changing the preload on the diaphragm. For actuation of the closing element, the closing element is connected to the diaphragm or to the further device.
The disadvantage with the known pressure reducers is that they are technically relatively complex, and therefore expensive. Moreover, one major problem of current pressure reducers or pressure regulators is that they cannot be operated in a particularly large inlet pressure range if the outlet pressure is to be held constant, without any significant fluctuations, irrespective of environmental factors and of the inlet pressure. This is because, if the pressure at the inlet is also high, high forces occur at seals owing to friction, and the force required to ensure adequate seal seating is high, making precise regulation of the outlet pressure more difficult. If the inlet pressure falls and if it approaches the outlet pressure to be set, on the other hand, said forces decrease. Moreover, regulation of the outlet pressure is affected by other factors, such as the flow rate, changes in temperature etc. In addition, the regulated outlet pressure is often subject to hysteresis.