Pressure, burst, temperature bench

THE SOLUTION PROVIDED BY LF TECHNOLOGIES

Main functions

Objective

Test high-temperature brake hoses in ramps and pressure steps until they burst.

The tests should be carried out in 4 stages: bleeding the hose, heating up and stabilising, building up pressure and maintaining it for several minutes, and increasing the pressure until it bursts.

Problematic Issues

The customer’s specifications included requirements such as a small footprint, the ability to test two hoses at a time and in a vertical configuration, etc.

Technical, operating, pressurisation and safety constraints were also imposed on us. It is essential that the test rig can be adapted to different hose lengths.

Solution and Result

Our expert teams have designed a bursting test bench capable of testing two hoses at the same time. The tests are carried out between 0 and 1800 bar in pressure and up to 200°C in temperature.

The hoses are housed in a thermal enclosure with a glass cover, which allows a high level of visibility of the products while ensuring the safety of the operators in the event of a rupture. The glass is resistant and has a self-cleaning treatment to facilitate maintenance and increase the life of the machine. To ensure that the bursting of one hose does not affect the other, the test rig has a wall to separate the two products.

The chamber is equipped with a temperature control system over the entire height of the chamber. At the bottom of the chamber is a sink to collect the ejected fluid, which is stored in a tank, with the possibility of being re-injected into the supply tank if it is deemed recyclable.

The test bench is equipped with a light source to make any faults visible and has a system to quantify any leaks.

The pressure build-up is perfectly controlled by servo cylinders associated with a pressure sensor.

To ensure the safety of the operators, the door of the pressure bursting test bench is closed by an electromagnetic safety lock. It prevents the temperature and pressure from rising if it is not locked and only opens if the safety conditions are reached (low temperature, low pressure). Before the test chamber is opened, a turbine forces the air to be renewed.

A light signal will also be visible during the entire test to avoid any danger.

The pressure burst test rig is capable of testing two hoses independently. A valve and a vertical slide adapt the test to the length of the hose.

The pressure test begins with the hose being bled of air before the test fluid is passed through.

The test rig then builds up the pressure to a specified level or according to a pre-programmed ramp. Once the plateau is reached, the pressure and temperature are maintained. This is done automatically, but the pressure build-up can also be controlled manually.

The operator selects the test parameters before starting the machine. He can choose :

• Bearing pressure
• Dwell time
• The rate of rise to bearing and burst pressure
• Temperature of the chamber.

At the end of the test, the burst pressure value is displayed on the pressure bench monitor.