Back to overview

Pressure Transmitters Used in Autofrettage

Pressure Transmitters Used in Autofrettage

Fuel injector lines in diesel engines withstand an enormous amount of pressure cycling through them. There’s so much, in fact, that the lines will fatigue more quickly if they’re not treated. Autofrettage is the technique that treats fuel engine lines, making these thick-walled metal tubes more durable and resistant to wear. Pressure transmitters are a part of this process, used in autofrettage of fuel injectors as a part of detecting cracks and ruptures, hydraulic pressure control, and hydraulic pressure sensing

How Does Autofrettage Work?

Autofrettage, which uses hydraulic systems monitored by pressure transmitters, doesn’t just treat fuel injector lines in diesel engines. The process is also commonly used in hydraulic cylinder manufacturing, LDPE production, oil field component manufacturing, and weapons manufacturing.

During the process:

  • A fuel injector line to be treated is first mounted in a fixture connected to the necessary hydraulic systems.
  • Hydraulic fluids, typically petroleum or water-based, are then pumped into the sealed fuel injector line. In order for this to be effective, pressure transmitter material must be compatible with these fluids.
  • A permanent, plastic deformation appears in the line if the pressure inside the line exceeds the elastic limit of the metal.
  • The pressure is limited so that as the pressure is released, elastic recovery of the fuel injector at the fixture orifice causes residual compressive stresses.

Pressure transmitters control the pressure of the autofrettage hydraulic fluid, detect imperfections or failures during processing, and monitor and control automated processes to close and seal the connecting fixture.

The Pressure Transmitter Designed for Autofrettage

The WIKA Pressure Transmitter for High Pressure Applications Type HP-2 is designed for superior performance in high-pressure applications such as autofrettage at up to 15,000 bar (217,550 psi) with long-term stability, high accuracy, and dynamic pressure curves.

The HP-2 offers:

  • Accuracy
  • Fast response times  
  • High working and burst-pressure ratings
  • Repeatability
Pressure Transmitters Used in Autofrettage