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Pressure Transmitter Usage in Hydroforming with Metal Forming Machine Tools

Pressure Transmitter Usage in Hydroforming with Metal Forming Machine Tools

Hydroforming (or hydro-molding) is a technique used to shape pliable metals – such as brass, copper, aluminum and stainless steel – into stiff, strong pieces and complex shapes. Hydroformed materials often have higher stiffness to weight ratios (strong but light) and smoother finishes than conventional die cast or stamped parts.

Hydroforming is achieved through the use of hydraulic systems monitored by pressure transmitters. Sheet hydroforming uses a negative mold of the part being formed. The sheet is placed inside a sealed chamber above the mold, and high pressure hydraulic fluids are injected above the sheet to press it down into the mold. In order for the sheet metal to be properly hydroformed, pressures can reach in excess of 15,000 bar.

Tube hydroforming is accomplished in a similar way, except the tube is pressurized from the inside and forced outward into a negative mold that extends the length of the tube. Both sheet and tube hydroforming require the use of accurate, high pressure transmitters for constant monitoring and control.

Advantages of Hydroforming

  • Easy to produce complex concave and convex geometries 
  • Reduced metal thinning and work hardening compared to other metalwork processes  
  • Reduced need for additional metal heat treatment


High Pressure Transmitter Use in Hydroforming Applications

Pressure transmitters are used for hydroforming in the following metal forming machine tool applications:

  • Hydraulic pressure monitoring 
  • Hydraulic pressure control 
  • Crack/rupture/detection 
  • Mold chamber sealing and leak detection 
  • Automated process control

Hydroforming metal sheets and tubes in metal forming machine tool applications calls for pressure transmitter material compatibility with high pressure petroleum and/or water based hydraulic fluids. The pressure transmitter is responsible for monitoring and controlling the pressure of the hydroforming hydraulic fluid, monitoring and controlling automated processes to close and seal the forming chamber, and detecting imperfections or failures during processing. 

The WIKA HP-2 high pressure transmitter has been designed for superior performance in high pressure applications like hydroforming up to 15,000 bar and with long term stability, high accuracy, and dynamic pressure curves in mind.


Pressure Transmitter Selection Considerations

  • Absolute or Gauge Pressure Measurement 
  • Media Compatibility for Pressure Transmitters 
  • Moisture Resistance in Pressure Transmitters 
  • Pressure Transmitter Accuracy and Errors 
  • Radio Frequency (RFI) and Electromagnetic Interference (EMI) in Pressure Transmitters 
  • Vertical or Horizontal Pressure Transmitter Mounting 
  • Vibration Resistance in Pressure Transmitters
With angular connector

With angular connector