Customer
Our client designs and manufactures sanitary fittings and accessories.
Tested product
Taps and sanitary accessories
Objective
To perform static and alternating pressure leakage tests on shower fittings and accessories.
The bench shall be capable of performing the following tests:
- Static pressure 16, 25, 35 and 100 bars.
- Alternating pressure from 8 to 50 bars with a frequency of 1 Hertz.
Problematic issues
The NF077 - Doctech 3 standard includes water hammer tests with strict characteristics (see graph):
- Very rapid pressure rise (from 5 to 50 bars in 0.15 s)
- High precision of pressure control (2%)
Various systems exist, notably the pneumatic pressure intensifier, which allows rapid pressure increases but with very little precision.
Solution and result
The proposed equipment is a self-supporting bench consisting of a recovery sink, a bonnet, a hydraulic circuit, a cyclic and static pressure generator and a control unit.
The bench is connected to the water supply circuit. The pressure of the connecting circuit allows air to be bled from the circuit.
The bench is equipped with a pressurisation system using a motorised plunger piston that compresses the water in the circuit. The displacement of the pressure generator piston gives a volume measurement. A sudden change in this volume measurement can be used to detect a leak or a burst.
In order to ensure accuracy and speed of execution, the plunger is in this case directly controlled by the drive, the control loop is much shorter. The control is based on self-learning cycles and pressure-dependent piston travel. The control software applies corrections to ensure the correct pressure and rate of pressure rise.
The product under test is connected to the tapping points on the front panel. Manual valves are used to supply or vent the product.
A bonnet system equipped with a safety switch cuts off the pressurisation if the bonnet is not closed. This ensures the safety of the operator.
