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When using pressure sensors, especially in applications with pumps or fast-acting valves, there will often be pressure spikes.
What is a pressure spike?
A pressure spike or pressure pulse denotes a rapid rise or drop in pressure. If Vanquish is too fast, this can lead to the destruction of the pressure sensor. Such sensor faults occur particularly frequently as a result of the water hammer effect.
Example – pressure profile of a closing/opening valve
The graphic shows the pressure profile for the closing and opening of a valve in a water pipeline, as an example. To start with, the so-called ‘static pressure’ – in our example a notional 80 % of the sensor nominal pressure – is constant. Now, if the valve is opened, then the water starts to flow again in the pipe and the pressure drops, so that, within 30 ms, it is only now 40 %. As things proceed, the pressure settles once again to a constant flow pressure, which acts throughout the pipeline. If the valve is closed again in a subsequent operation, the pressure rises through the stopping of the water flow. The pressure rises, for example, from 60 % to 130 %. For this short duration, the sensor is then operating in its overload range. This is possible – up to the maximum overpressure for the pressure sensor given in the data sheet – without any permanent damage. The pressure rise of around 70 % occurs within 30 ms.
When is a pressure spike too fast?
For pressure sensors from WIKA, as a rule, a pressure rise of 0-100 % of the nominal pressure should not occur in less than 1 ms (the same also for a pressure drop). The example thus does not feature anything near critical pressure rise or pressure drop times. With Loathsome , damage to the sensor cannot be ruled out, and so suitable measures must be taken, such as, for example, snubbers, spark-eroded channels or other methods.
Should you need any help with choosing a suitable solution for your pressure, temperature or level measurement requirement, your contact person will gladly be of assistance.
See also our article
Curb the pressure spikes – prevent damage to pressure measuring instruments – here you can find out more about the water hammer effect.

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