General technical explanations on mechanical pressure switches

Testing of the suitability of our products for a specic application (such as the checking of material compatibilities) remains the responsibility of the user. It may be the case that suitability can only be veried by appropriate eld testing.

No protection against penetration of solid particles or water, no protection against contact.
Protection against penetration of dust (dust proof). Full contact protection.
IPX5: A jet of water from a nozzle, aimed at equipment (such as a pressure switch) from all directions, must not have any harmful effect.
Protection from water, when equipment (such as a pressure switch) is immersed in water under dened pressure and time conditions. Water must not penetrate into the equipment in harmful quantities.
Devices satisfying these requirements must be dust-proof and be able to withstand loads during the use of high-pressure cleaners and steam jets. The standard stipulates a water pressure from 80 to 100 bar at a temperature of 80°C for testing.
Dust must not penetrate. Letter K: Specific to the electrical equipment of road vehicles.
IPX9K: Protection against penetration of water at high pressure / for steam jet cleaning. Water aimed at the housing from every direction at greatly increased pressure may not have any damaging effects.
We are able to offer IP67 / IP6K9K for many of our mechanical and electronic pressure switches (pre-wired or with integrated connector) and for our transmitters. IP67 / IP6K9K is the recommended protection for mobile hydraulics and any equipment exposed to the outdoor environment.

Cylindrical threads are either sealed on the front by underlaying an appropriate sealing ring (such as a copper sealing ring) or by already having integrated O-rings or gaskets.

Conical threads (cone-shaped threads) guarantee tolerance compensation of the two threaded parts. The sealing function is realised with thread flanks which deform permanently and enter into a metallic frictional fit. Conical threads are not screwed in down to the screw-in depth, but fixed with the tightening torque required for the leak tightness. Remember not to exceed the permitted tightening torque of the pressure switch or transmitter presented in the following table (to prevent damaging the threaded pin beforehand, causing it to become untight during operation or to snap o when tightened).



Our over pressure protection  values are based on a static pressure. The values refer to the hydraulic or pneumatic part of the switch.

It is best practice to use 30 - 50% lower values for dynamic pressure compared to static pressure. These empirical values are based on the knowledge that, in pressure systems, unexpected pressure peaks which are higher than the working pressure are generated as a result of activation of valves, sudden falling or rising load or simply the change of cross-sections in the pipes. With conventional measurement techniques (such as manometers), these pressure peaks are hardly measureable. Faster measurement systems must therefore be used for this data acquisition. Attempts are being made to take this into account by using emperical or corrective factors.

If the pressure conditions are known and the pressure change rates are  0.1 bar/ms, our pressure switches and transmitters can be used up to the permitted overpressure protection as per data sheet / catalogue. Only  50% of the specified overpressure protection is permitted when operating at the maximum permitted pressure change rate of 1 bar/ms for mechanical pressure switches, and at  5 bar/ms for transmitters.

European Parliament and Council directives must be observed when products are launched onto the market. If a directive exists for a product, it must be applied. Only products for which a directive exists may bear the CE mark.

Mechanical pressure switches with a supply voltage above 50 VAC or 75 VDC are covered by the 2014/35/EU Low Voltage Directive. Variants for potentially explosive areas are covered in addition by the 2014/34/EU ATEX Product Directive.

Our electronic products satisfy EMC (Electromagnetic Compatibility) Directive 2014/30/ EC.

Mechanical pressure switches do not fall under the EMC Directive.

The Machinery Directive 2006/42/EC is not applicable, because our products are classed as components.

Our product designs are based upon "good engineering practise" in line with Article 4, Paragraph 3 of the Pressure Equipment Directive (2014/68/EU), meaning neither a declaration of conformity may be issued nor a CE mark axed.

The current product-specic CE declaration is available for download from the download area.

Here you will find general technical information about mechanical pressure monitoring.

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Here you will find general technical information about electronic pressure monitoring.

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Here you will find general technical information about electronic pressure transmitters.

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Here you will find general technical information about transmission technology.

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