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About water pressure switches
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What was a water pressure switch?
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What types and types of water pressure switches are available?
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Purchase criteria for water pressure switches - what is it all about?
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Practical advice
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FAQ - frequently asked questions about water pressure switches
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Conclusion: How to buy the suitable water pressure switch
What was a water pressure switch?
A water pressure switch is functionally similar to a standard air pressure switch, which switches a compressor on and off again depending on the pressure in the pressure vessel. A pressure switch for water basically does the same, but for the medium water, and is designed specifically for it.
Pressure switches use mechanical or electronic sensors to detect the currently applied pressure. If it exceeds the desired pressure, the pump controller switches off the pump. If the respective switch-on pressure is undercut, the electrical switch contacts close and the pump starts again. These processes can either be performed purely mechanically by directly actuating the switching contacts via a deformable pressure diaphragm or electronically via a pressure sensor and control electronics.
Water pressure switches are used as pressure regulators for controlling domestic water machines, garden and cistern pumps, submersible pumps and other water pumps. They are also suitable for upgrading an existing pump to the domestic water supply, ideally in conjunction with a pressure vessel or pressure vessel.
What types and types of water pressure switches are available?
Mechanical pressure switches and those that function electronically are basically differentiated. While mechanical pressure switches have the advantage that they do not require their own power supply for operation, pressure switches with electronic control often offer useful additional and comfort functions.
In the case of the types of construction, there is a differentiation between versions with a pressure connection and those with two connections that are mounted in the water flow path.
Purchase criteria for water pressure switches - what is it all about?
Pressure switches are available with different connections for different applications. Their control range ranges from pressures below 1 bar to 12 bar. Pressure vessels often already have screw terminals for pressure switches, which are closed with a screwed-in blind plug.
This is often the case with domestic water plants. The thread designation and the maximum permissible operating pressure in bar can be found in the technical data.
The pressure range should be as adjustable as possible in order to be able to adapt the water pressure to different requirements. For a domestic water supply, for example, a pressure of 2 bar to a maximum of 4 bar is sufficient, but if larger height differences or long conveyor distances have to be overcome, powerful pumps and correspondingly higher pressures are required in the range of 5 bar to partly over 10 bar.
If different pressures are often required, electronic pressure switches are an advantage. They not only switch very precisely, but also allow a simple and fast setting of on and off pressure.
This allows an ideal adaptation to an existing or to be built-up domestic water supply.
Practical advice
Water pressure switches are only suitable for a single liquid medium, namely water. This means clean fresh water, for salt water or other aggressive media, you need especially suitable water pressure switches. A pre-filter should be used as far as possible for trouble-free operation and a long service life. This filters particles such as sand grains or rust out of the water and protects both the pressure switch and the pump from damage.
FAQ - frequently asked questions about water pressure switches
Can a pressure switch for water be used exceptionally and temporarily for other liquids?
Housings, seals and the pressure sensors are designed for the contact and viscosity of conventional, non-corrosive water. Other liquids can cause malfunctions or irreparably damage the pressure switch. Flammable liquids may also cause an explosion.
My mechanical pressure switch no longer works, can ich repair it myself?
Apart from the settings for on and off pressure according to the operating instructions, there are no settings or repairs to be carried out by the user inside the device. The coil spring on the pressure diaphragm is under very strong preload, an incorrect handle can cause serious injury. Therefore, only have repairs carried out by the manufacturer's service department.
What was a domestic water supply?
A domestic water supply consists of a combination of pump, pressure switch and a container. This container is equipped with a membrane inside and partly air-filled to provide the accumulator pressure and to avoid too frequent switching on and off of the pump with only small water withdrawals. A domestic water supply allows the use of rainwater or, if permitted, groundwater for irrigation and cleaning purposes.
Conclusion: How to buy the suitable water pressure switch
The maximum permissible operating nominal pressure must always be higher than the highest expected water pressure, i.e. the pressure that the pump can build up at most. For example, if the pump provides a maximum of 6 bar, the pressure switch must also be designed for a maximum of 6 bar (better still).
If dry running protection is required for the pump, electronic pressure switches with corresponding functionality can be used for this. The pressure range is also important, i.e. the setting range from the desired switch-on pressure to the switch-off pressure.
If the pressure switch is to be used not only in the house but also in the garden, make sure that it is suitable (protection type). A switch is convenient if the circuit of the pump is not already to be switched separately.
For a flexible use, when frequently different pumps are to be connected or a mobile use is desired, plug-in pressure switches are practical for an easy connection to a 230 V socket.
Especially in connection with a domestic water supply, an existing leak detection is advantageous. It protects the domestic water supply from constant switching processes in a short sequence if a tap has not been completely closed and signals when a leak occurs at the domestic water supply.