Pressure Reducing Valves

GESTRA Overflow Valves and GESTRA Pressure Reducing Valves

Pressure reducer for use in industry and plant construction

Pressure-reducing valves, also referred to as pressure reducers are primarily used in industrial systems, in plant construction (e.g. steam networks), or in process engineering. Pressure reducers are available in a range of different versions. Pressure-reducing valves with flange connections or welded flanges and threaded connections are listed on the following pages. You will find the optimal combination of valve and connection for your application here. If you do not find the right pressure-reducing valve for your application, please do not hesitate to contact us - we look forward to your enquiry and will provide you with the suitable solution!

What is a pressure-reducing valve?

A pressure reducer is used in a pipe system with high or fluctuating pressure. It protects downstream fittings from excess pressure, i.e. before a maximum pressure (maximum nominal pressure (PN)) is exceeded. At the same time, it allows the consumption and flow speed of media, such as water, to be reduced. Pressure-reducing valves are suitable for media such as compressed air, natural gas, nitrogen or even water, oils and fuels which means they are suitable for a wide range of industrial applications. You will find technical data and documentation for each pressure-reducing valve on the individual product pages.

Pressure reducers made of stainless steel, brass or gunmetal

We offer the right pressure reducer for different connection options, seals, and setting pressures: Regardless of whether the pressure reducers need to be suitable for water, compressed air, or steam. You will find a selection of the most common materials available to you directly from stock.

Function, installation, and maintenance of pressure reducers

As soon as the valve is screwed into the pipeline, the front pressure area can be flooded. A full pressure load in the pressure reducer is created. Now open the valve with the adjusting spindle above the fitting. The spring plate and compression spring are now under compressive stress. The seal floods the back pressure area with the liquid (e.g. with water in the case of water pressure reducers). The rising pressure in the back pressure area floods the space under the elastomer diaphragm. Meanwhile, bar should be shown on the thermometer. The pressure of the elastomer diaphragm closes the valve. The back pressure is then adjusted by turning the adjustment spindle and opening the rear shut-off valve. This is how pressure reducers control highly fluctuating front pressure conditions. It is important to close the front shut-off valve during maintenance when the unit is installed. The liquid may then be drained from the back pressure part. Always follow the operating instructions when commissioning the valve in order to avoid operating errors, etc.

The product used for the description is a pressure reducer with diaphragm valve (type 681). If you have any questions on function, installation, or maintenance, please feel free to contact our specialists.

DVGW approval for pressure reducers

Pressure-reducing valves for drinking water must be DVGW-approved. Delivery of drinking water pressure reducers without DVGW approval is ruled out. In addition, a sound insulation test is suitable for installation in buildings. Our pressure-reducing valves with a balanced single-seat valve are available from stock up to a nominal size of DN32. Here you can find out more about pressure-reducers for drinking water.

Diaphragm type pressure regulator

Pressure regulators (or simply regulators) use a main spring to exert force on a diaphragm. This force can be adjusted by turning the control knob. In the middle of the diaphragm there is a sealing element which initially sits on the face of the regulator piston and seals it through the set force of the main spring and the spring of the regulator piston.

By adjusting the main spring, the regulator piston is pressed down, thereby releasing the lower seal seat, while the face of the regulator piston continues to close the sealing element in the diaphragm. This frees the flow from the pressure port to the working port for venting and bleeding the system. In this position, small pressure fluctuations are compensated for by slight movements of the regulator piston and the associated change in flow at the lower seal seat.

If the pressure at the working port rises above the set working pressure, this generates a force on the underside of the diaphragm that significantly compresses the main spring. Due to its spring, the regulator piston moves upwards and completely closes the lower seal seat, but no longer reaches the seal seat in the diaphragm.

The air now escapes through the sealing element in the diaphragm and a vent hole on the housing of the compressed air control valve. This process is called secondary ventilation.