Carrying out a fully automatic pressure test using the contraction method

29. March 2023 | by Dr. Johannes Hopster

Application

Once you have set up the device as described in the previous part of the application, connected the required measuring equipment and rinsed the relevant components before commissioning, carry out the next steps directly on the smart memo.

Enter the pipe data and test parameters in the menu item W 400 Contraction method

Enter the pipe data and the desired test pressure in the input field. Set the selection parameter “MPP remote controlled” to “Yes” so that the MPP is controlled by the smart memo during the pressurization and pressure keeping phases of the test procedure.

After setting the zero point of the pressure sensor (set zero point also in the main menu of the MPP), switch to the relaxation phase by pressing F2.

Relaxation phase

At the beginning of the relaxation phase, the valve of the EDS2 automatic water drain opens to prevent a pressure build-up inside the pipeline. At the end of the phase, the valve closes automatically.

If the MPP is not yet connected to the smart memo or is not yet ready for use, a request is made at the end of the depressurisation phase to subsequently establish the connection.

In the current implementation (02/2023) of the automatic system, a final confirmation by the user is required at the end of the relaxation phase immediately before the initial pressure build-up begins. The rest of the test runs completely automatically without user intervention.

Pressurisation phase

If you answered “No” to the query at the beginning of the relaxation phase:
The relaxation phase must be ended by pressing the button “Continue”. Now the MPP is initialised. If the connection between the MPP and the smart memo via the connection cable does not yet exist, a corresponding message appears. As soon as the MPP is initialised, a message appears asking whether the pressurisation should be started. After confirming with OK (F2), the smart memo switches to the pressurisation phase and the MPP starts operating automatically. The pressurisation is implemented via the speed control of the MPP without overshooting. As soon as the preset test pressure is reached, the smart memo automatically switches to the pressure keeping phase.

If you answered “Yes” to the query at the beginning of the relaxation phase:
No further intervention is required from you. The smart memo has automatically switched to the pressurisation phase, initialised the MPP and started pressurisation.

Afterwards (at the beginning of the pressure keeping phase), a message is sent from our air volume determination, which was used to determine whether there is too much residual air in the pipeline. We have already compiled further information on air volume determination for you here and here.

Pressure keeping phase

The smart memo continues to control the MPP and maintains a constant pressure at the pre-set test pressure for the duration of this phase. At the end of the 30-minute phase, the smart memo automatically switches to the rest phase.

Rest phase

With the change to the rest phase, the pressure control of the MPP by the smart memo is automatically terminated. The MPP is reset to the main menu and could already be taken out of operation, emptied and stowed away again after removing the cable connection to the smart memo and closing the ball valve on the HANS test head (please do not close the wrong ball valve).

The smart memo checks the pressure drop during the rest phase. If this is greater than 20%, the test is automatically terminated because there is usually a leak in the pipeline.

After completion of the 1-hour rest phase, the smart memo automatically switches to the pressure drop test.

Pressure drop test

Now the EDS2 automatic water drain starts to reduce the pressure automatically. The valve opens gradually and regulates the pressure reduction in such a way that the specified target pressure is reached in the best possible way. At the same time, the drain volume is measured by the connected EDS2-V and transmitted digitally to the smart memo.

When the target pressure is reached, the valve of the EDS2 automatic water drain is completely closed.

The smart memo now automatically switches to the main test as soon as a pressure increase is detected as a result of the contraction of the test pipeline.

A test of the discharge volume and the generated pressure drop in accordance with the specifications of the current worksheet W 400-2 is carried out in the background. If the result of the test is negative, a corresponding message appears at the beginning of the main test, otherwise the test continues without a message.

Main test

The smart memo registers the pressure increase as a result of the contraction and gives an evaluation according to the regulations after the 30-minute main test has been completed.

If the pressure curve is within the permitted range, the evaluation is positive.

If the pressure drop during the main test is too high, the smart memo automatically switches to the extension of the main test.

Extension main test

The smart memo registers the pressure development in this phase and gives an evaluation according to the regulations at the end of the 60-minute extension.

At the end of the phase, the smart memo automatically switches to the results page or optionally to the pressure release phase (if set beforehand, see below).

Pressure release phase

The pressure release phase can optionally be activated in the menu item settings. If the phase is activated, the EDS2 automatic water drain automatically generates a pressure reduction to relieve the pipeline and end the test.

Thus, the test pipeline is not unnecessarily loaded for a long time by the test pressure after the end of the fully automatic pressure test.