Poppe + Potthoff Maschinenbau produces equipment for the process of Autofrettage used for R&D, prototypes and other components, but also serial production. Autofrettage can increase fatigue strength of components that are subject to a constant change of high and low pressures.

Autofrettage System | Autofrettage

What is Autofrettage?

Autofrettage is a method for increasing the fatigue strength of components for use under both high pressure, as well as  pulsating pressures. 

The process compresses a container’s inner surface, making better use of the material’s structural properties. The process can reduce fatigue concerns in pulsating applications and lets engineers reduce tubing thickness in high-pressure applications without sacrificing strength, life, or safety. 

The autofrettage method is based on the reciprocal relationship of the plasticized inner zone and the elastically deformed outer zone. The components are placed under so much pressure that their interiors become plastically deformed. After relaxing, pressure stresses are created in these areas, which prevent the outer zone from resuming its original shape. Instead, it remains stretched. This prevents crack formation in the later application, increases the service life of the components, and thus offers the corresponding cost reduction potentials.

Our systems are UL or CE compliant as required. In addition, we offer you direct on-site service and support. 

Industries & Applications utilizing Autofrettage

Serial Autofrettage For Rails

With these systems, the durability of common rails can be increased in series. Autofrettage is performed automatically after the rails are inserted, with several radial and axial sealing points provided.

The test system consists of two sub-assemblies that are combined into a single compact unit. The pressure generation system and the electric control cabinet are installed on the left side. The right side has been designed as a test chamber. An automatic door is installed in front of the chamber. A safety lens in the protective door allows for a good observation of the test object. The protective door cannot be opened during the autofrettage, since a mechanical interlock occurs via the safety switch. On the left side, the pressure converter is installed in a horizontal position.

Performance data:

Autofrettage Prototypes & Development

The Autofrettage system is a research and development facility. Due to the high product variability, various components or prototypes can be autofretted on the system as the pressure is freely programmable. The control panel is located at ergonomic height on the right side. All relevant data is displayed to the operator and can be quickly edited at any time.

Performance data:

Autofrettage schedule:

  1. Inserting the assembly into a device
  2. Close the protective door, close the sealing tips of the clamping device with minimum pressure
  3. Filling-up the system
  4. Position the pressure converter
  5. Autofrettage pressure build-up with proportional clamping pressure increase
  6. Pressure-holding time and auto-frettage
  7. Pressure reduction
  8. Sealing tips and protective door
  9. Remove component 

Universal Autofrettage

Because of its high variability, Universal Autofrettage is ideal for research and development purposes as well as for smaller series. It increases the fatigue strength of high-pressure components such as pipelines, valves, rails, pump heads and pressure vessels.

For variable geometries
components with different geometries can be auto-fretted on this system with a high degree of flexibility. The Autofrettage parameters are freely programmable and editable.

Pressure converter
The pressure converter consists of a drive and a high-pressure component. The hydraulically-driven pressure converter also acts as a mediator.

Drive part
The actuator is driven by the linear drive part. It is designed as a hydraulic cylinder. The components are a piston rod with piston as well as a cylinder tube with cylinder bottom and cylinder cover. A displacement measuring system is connected to the piston. The displacement transducer indicates the position of the pressure converter. The hydraulic pressure is fed into the cylinder bottom.

High-pressure part
High pressure is created in the high-pressure part of the pressure converter. The actual pressure of up to 16,000 bar is measured in the high-pressure circuit. The control takes place via a proportional valve. The piston position of the pressure converter is detected by a remote measuring system. The stroke length and the lifting speed are monitored during the pressure build-up.

Performance data:

Autofrettage Plant For Diesel Injection Lines

High pressure lines for diesel injection are automatically prepared with this system for continuous use at pulsating pressure in series. Different components can be auto-fretted with the system by changing the device.

In-tens series
For manual insertion and removal of up to ten lines, a protective disc opens in the front of the device.  Here, The Autofrettage pressure can be programmed. All other relevant data is also displayed to the operator.

Performance data:

Poppe + Potthoff =
Absolute Precision Dependable Quality Premium Support Knowledgeable Staff German Engineering

As specialist in high-pressure technology, Poppe + Potthoff Maschinenbau supports the development and production of extremely resilient metal and plastic components – in particular for the automobile, shipping and machine building sectors as well as fluid and medical technology. 

Other Testing Solutions

Impulse Testing

Pulse/Burst Testing


Pressure Generation

Leak Testing

About the Poppe + Potthoff Group

15 locations in 9 countries.

Poppe + Potthoff Gruppe has 15 production plants and sales offices in 9 countries. The name Poppe + Potthoff always indicates the highest quality – a promise to which our customers rely on, regardless of which Poppe + Potthoff location they work in.