Contamination Indicators

Overview

Filter elements are economically used only if their dirt-holding capacity is fully utilised. This is achieved by using filter housings with a contamination indicator.

The following designs are available:

• Differential pressure indicators
• Pressure indicators / switches / gauges
• Vacuum switches / gauges
• Pressure transmitters

With pressure filters, the pressure is measured upstream and downstream of the filter element (differential pressure). With return-line filters the pressure is measured only on the upstream side because, depending on the tank design, atmospheric pressure exits on the downstream side of the filter element. With suction filters the vacuum is measured downstream.

This red button remains visible until it is pushed in during the daily check which is to be performed while the plant is at operating temperature. If the button pops out immediately after being pushed in, the filter element must be replaced.

This optical function may also be used for generating contactless electrical signals. For this purpose an electrical upper part is fitted over the hydraulic / optical part. This upper part incorporates all electrical switching elements.

Features

• Optical and electrical indicator with standard check function
• Normally open / normally closed combination - standard feature
• Electrical function, easy to install at a later time
• Two-step indication, at 75% and 100% optional
• Non-bypass design