High-Pressure and Low-Pressure Testing
For testing internal high pressure and low pressure fatigue strength of components we have test facilities for high pressure (currently up to 3,000 bar cyclic) and low pressure (up to 300 bar cyclic):
Internal high-pressure testing
The high-pressure (HP) installation consists essentially of a pressure transformer and a test chamber. The pressure transformer is driven hydraulically on the primary side from IABG's 280-bar compressed oil supply network. A closed-loop control circuit is set up for this with a servo valve and digital controller.
On the secondary side (approx. 1:20 transformation) you can apply hydraulic pressures of up to 3,000 bar (cyclic) or 4,000 bar (static) to one or more test items. The hydraulic oil pressure can be applied directly to one test item or to up to 18 test items simultaneously via a high-pressure distributor. If the high-pressure distributor is used, the same pressure is applied to all the test items (parallel switching).
In cyclic test mode (pulses), the controller applies pressure to the test item with a sinusoidal characteristic. The unavoidable leakage within the pressure transformer causes the volume of oil to decrease on the secondary side. The piston of the pressure transformer creeps towards the secondary side. The controller compensates this when a specified limit is reached by stopping input of the setpoint value and retracting the piston. The time period between these "get oil intervals" is a highly precise failure criterion for recognising damage to the test items. In the case of parallel switching, each failed test item is removed and the test connection on the distributor closed. Upon completion of the test, there is a distribution of failures over time, which permits you to draw conclusions about the dispersion in the test batch.
The attainable test frequency depends largely on the overall internal volume of the test items (individual volume x number of test items). Any system-specific leakage or stiffness of test items against expansion also influences the test frequency.
The test machines and test services are accredited in compliance with DIN EN ISO 17025.
- Test items: fuel injector rails with connectors, injectors and pressure sensors for example
- Test chamber dimensions (L x W x H): 0.8 m x 0.8 m x 0.4 m
- Test: internal pressure test (pressure threshold test)
- Test facility: HP test installation
- Fastening: test adapter (provided by customer), high-pressure distributor with 18 test connections
- Test parameters and sequence: Minimum pressure value P_min: 50 to 100 bar (depending on the installation)
- Maximum pressure value: P_max = 4,000 bar
- Ultimate number of cycles: n_G = 107 load changes
- Customer tasks: as far as possible, fill the accessible internal volumes with fillers (e.g. aluminium rods or similar) in order to keep the volume of oil to be compressed as low as possible. In this way you can increase the test frequency and reduce the test duration.
Internal low-pressure testing
- Test items: petrol fuel injection components, power steering pipes, cooling pipes and intercoolers with a pressure of 350 bar, for example
- Effective dimensions (L x W x H): 1.2 m x 0.7 m x 0.7 m
- Temperature range: -40 to 180 °C
- Test parameters: pressure medium is hydraulic oil or other media via media separator
- Test procedure upon agreement
- Test frequency: maximum 10-15 Hz (depending on test volume)
Wärtsilä Finland Oy, 2016
Gutor by Schneider Electric (Schweiz), 2015