Bosch Condens 7000 F - Carrying out Gas Tightness Test

Inspection and maintenance
Condens 7000 F – 6720871560 (2019/11)
34
11.4.2 Carrying out gas tightness test
 Turn off appliance shut-off valve.
 Undo locking screw on test nipple by turning it through 2 revolutions.
 Push the test hose of the U-tube pressure gauge onto the test nipple.
 Open the fuel shut-off valve and wait for the pressure to stabilise.
 Note and record the pressure.
 Close the appliance shut-off valve and check the pressure again a
minute later.
 Calculate the pressure drop per minute from the differential.
By means of the determined pressure drop per minute and the test
volume (V
test
), check in the following diagram ( Fig. 37, page 34)
whether the gas train is still useable.
Fig. 36 Testing the gas supply pressure
[1] Test nipple for measuring the gas supply pressure and for venting
Fig. 37 Permissible pressure drop per minute for the internal leak test with gas pressure present
[1] “Valve tight” range = applies to new installations
[2] “Valve sufficiently tight” range = valve can be used without
restrictions
[3] “Valve leaks” range = valve may not be used
(perform a test as described in the following)
x Test volume in litres
y Pressure drop in mbar within one minute
Read-off example: test volume (V
test
) 5 litres and pressure drop
4 mbar/min = range 3 (valve leaking = valve may not be used)
carry out test as described below.
If you detect a steep pressure drop of > 10 mbar/minute at a test volume
of (V
test
) of < 1 litre, increase the test volume (V
test
). For this include the
pipework up to the next shut-off valve in the tightness test and repeat the
test using the new test volume (V
test
).
If the read-off point for the test volume (Vtest) and pressure drop per
minute lies within the "Train leaks" range (see Read-off example), you
must carry out the test described below.
NOTICE:
Risk of material damage due to a short circuit!
 Never spray or let leak detection agent drip onto cable entries, plugs
or electrical cables/leads.
 Cover areas at risk before testing for leaks.
 Check all joints in the tested pipework section using a foaming leak
detection agent.
 If required, seal any leaks and repeat the test.
 If no leak is detected, replace the air/gas ratio control valve.
Complete the leak test
 Remove hose.
 After completing the measurements, retighten the locking screw of
the test nipple.
 Check tightness of the test nipples.
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