sauermann E INSTRUMENTS 1500, Operating & Maintenance Manual, Page: 107 / 170

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Details of the test:
The standard UNI 7129-1: 2015 can be adopted for testing new piping systems or reconditioned ones.
This test requires to charge the piping up to a pressure between 100 hPa and 150 hPa, then wait for a
stabilization which must last at least 15 minutes and required in order for the thermal effects caused by the test
gas compression to fade out, and finally to test the piping tightness by analyzing the decay of pressure over time.
The maximum pressure decay measured, expressed as a function of the piping volume, must be smaller than the
values shown in the following table:
Table 1.
E4500 allows the user to customize the stabilization phase through the following parameter:
WAIT TIME: it is the stabilization time and can be set by the user from 15 to 99 minutes. Please note that
UNI 7129-1: 2015 standard requires a stabilization time of at least 15 minutes, anyway there is the possibility to
skip stabilization by pressing ' ' button.
VOLUME SETUP: An accurate tightness test performed according to the UNI 7129-1: 2015 standard requires to
know the piping volume.
Because this data if often unavailable, E4500 splits the test from the beginning into two different paths:
Default : valid for systems with a volume under 100 dm
3
(liters), the most frequent, where it is not required to
enter the value of the volume since it is assumed that the system has a volume of 100 dm
3
.
Manual: in this case it is necessary to set the volume of the system by entering the numeric value if known, or by
calculating the amount as the sum of the contributions of the different sections of piping or, even, by assessing
the measurement with a simple procedure that requires the injection into the system of a known amount of gas
using a syringe.
If you use volume calculation, for each section of piping it is necessary to set the material, the nominal diameter
and the length of the same. E4500 calculates the volume of the section ("partial volume") and it adds it up,
activating the context key ' ' (sum piping), to the calculation of the volume of the system. To correct any
errors of to modify the current calculation, the subtraction operation is also allowed by activating the context key
' ' (subtract piping).
When the 'Volume measurement' option is selected instead, the procedure, described also in the flow charts of
the tightness test according to UNI 7129-1: 2015, is described in the following steps:

Close both valves of the piping kit supplied for the test.

Connect the syringe to the kit opposite the pump.

Press the key relative to the context key ' '

Open the valve on the side where the syringe is connected, take exactly 100 ml (100 cc) of the gas present in
the system.

Wait for the stabilization of the pressure of the system. After a few seconds, the device displays the measured
volume. The suggested value can be accepted by pressing the key ' ' and then modified by selecting, in
"UNI 7129 Configuration" the line "volume".
It is also possible to repeat the measurement of the volume by pressing the key relative to the interactive
function ' '.
—————————————————————————————————————————————————-
Once the stabilization parameter has been set the user can proceed with the tightness test. By pressing the key
relative to the context key ' ', first the test pressure is indicated, as required by law, then you can access a
screen which displays the pressure reading of the inputs of the device.
After zeroing the device and putting the system under a pressure of at least 100 hPa, it is possible to start the
tightness test by pressing the key relative to the context key ' ', which starts the stabilization phase. In the
stabilization screen, the following values are displayed:


Internal piping volume
(litres)
Wait time
(minutes)
Maximum pressure decay allowed
(hPa)
V ≤ 100 5 0,5
100 < V ≤ 250 5 0,2
250 < V ≤ 500 5 0,1
V+
V-
OK
