Preparing A Duct System For Testing - Lindab LT 600 Mode D'emploi

5. Preparing a duct system for testing

Figure 3: Connection to the duct system
The duct system should be tested in accordance with
DIN EN 12237, DIN EN 1507, DIN EN 1507 and DIN EN
12599 . A specific pressure may be stipulated as stated
in the standards .
Any positive or negative target pressure can be
selected within the measuring range . If the duct system
is particularly large or complex, leakage testing can
be restricted to sections of the system . (See DIN EN
12599)
DIN EN 12599 compliant leakage testing should be car-
ried out while the duct system is being installed, when
the ducts are still accessible (for example they have not
been insulated yet) . The duct surface area being tested
should always be greater than 10 m² . The duct surface
area should be measured and calculated as defined in
DIN EN 14239, and should be established in advance .
You are recommended to estimate the anticipated leak-
age flow rate in advance (see the appendix) .
Before you start testing, seal off the duct section being
tested from the rest of the system . All openings, out-
lets, etc . must be carefully sealed .
It is extremely important to seal properly around
the openings and the test connections.
The connecting points in the duct system being tested
must be defined in advance, for the 50 mm air hose as
well as the thin pressure measuring tube . The connect-
ing points should be about 2 m apart from each other
to prevent one affecting the other .
Use suitable joints to prepare the connections for the
50mm air hose and the pressure measuring tube .
Do not subject the hose connections to torsional
stresses.
Use the connection on the front (10) for positive
pressure, and the connection on the top (5) for
negative pressure.
Always use adapters on the front, even for negative
pressure testing.
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manual-LTEST-1082_EN-DE-FR-SE.indd 6
Next, attach the thin pressure measuring tube to the
"+" connection (2) on the front, to the left above the 50
mm connection .
The pressure measuring tube is always attached
to the "+" connection (2). The device automatically
detects positive pressure and negative pressure.
The "-" connection (3) must be left clear.
A bayonet closure is used for the "+" connection of the
pressure measuring tube: turn clockwise to lock and
counterclockwise to open .
In principle, you should always start the leakage
test initially without an adapter . After you find out
the leakage flow rate, you can use the relevant adapter
to improve the measuring accuracy . See page 4 . The
adapters have different names, indicating the maximum
measurable flow rate in l/s .
DIN EN 15727 compliant measurements usually use
lower flow rates and are carried out in the same way . It
is also possible to depart from the recommended spac-
ing of 2 m between the hose and the tube . In order to
take measurements on the pressure side for very small
components, the thin 4m tube can be plugged directly
into the adapter instead of the 50 mm hose, and a
nipple connection is used with the component .
2012-03-28 12:32:38