Parts inspection

Inspection of engine components for blowholes in cooling water and oil ducts

In order to ensure consistent quality in the production of injection molded parts for engine construction, it must be ensured that there is perfect flow through the channels.

The given test pressure and the measurement of the flow provide information about the quality of the component to be tested.

Good part

Bad part


During the production of engine components by injection molding, blowhole inclusions can occur in concealed channels. These cause a narrowing of the channel and can lead to partial or complete blockage. A proper flow of the corresponding medium is no longer guaranteed.

Until now, only a single-unit inspection by means of endoscopic measurement was possible. This was very time-consuming and could not be automated, taking into account short cycle times.


To provide a measuring method that enables the component to be checked for inclusions in the shortest possible cycle times.


The Vögtlin electronic pressure controller equipped with a pressure transmitter offers a comprehensive approach. This advanced solution allows for the determination of channel narrowing or blockage by utilizing a predefined test pressure and precisely measuring the flow. This enables quick differentiation between compliant and reject parts within very short cycle times.

Customer first performs a leak test for the entire system. Good part is determined by endoscopic examination and designated as “master part” for the test. Now the flow rate at test pressure 30 mbar g is determined. This value is used as a guide value for the assessment of the other series parts to be tested.

Depending on the size of any shrinkage cavities that may be present, there is a small to significant drop in the flow rate at a constant test pressure. This makes it possible to reliably test cavities/channels that are difficult to access in a cost-effective and effective manner.MEMS technology insures a long-term stability without any drift as long as the gas supply is clean and dry.
Dual temperature calibration avoids error caused by ambient and gas temperature better than alternative mass flow controllers.

Key features

  • Precise and fast control
  • No open/close valves required thanks to tightly sealed control valves
  • High repeatability
  • Real gas calibration / Multiple gases per device
  • High savings possible with mixed gases
  • Independent of temperature and pressure
  • Easy to maintain


  • Analog
  • Modbus RTU
  • Profibus DP-V0/DP-V1
  • Profinet
  • EtherCAT
  • EtherNet/IP

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Download Application: Inspection of engine
components for blowholes

PDFApplication Spotlight Blowholes InspectionApplication SpotlightsENDE