Leister WELDY 124.306 Instrucciones De Funcionamiento página 4

Cross-section of an overlap weld
Seam thickness reduction = A – B
A : Thickness of the upper and lower membrane
B : Thickness of the welded seam
C : Welded section 1
D : Welded section 2
E : Test channel
Preparation
• Connect ball valve (4) to compressed air.
ATTENTION: Connection up to maximum 6 bar (80 psi). If the pressure of maximum 6 bar
(80 psi) is exceeded, a pressure-reducing valve (not in scope of supply) must be mounted
on the compressed air connection (4).
Testing
The test conditions, such as test pressure and test duration, must be adapted to the welding mate-
rial, welding material thickness, test channel dimensions and temperature.
• Precondition: Both ends of the test channel must be airtight, e. g. close off by hot gas welding or with
clamping device.
• Place the compressed air tester with test needle at the end of the test channel as follows:
– Heat the point to be tested on the test channel of the weld seam using a Weldy hot air blower with pen-
dulum-like movements (Figure D).
– Place test needle (2) approx. 2,5 cm into the test channel (Figure E).
Fig. D
• Test method:
– Open the ball valve, the manometer (3) must display the calculated compressed air value (bar/psi) (Figure F).
– The overlap weld seam is regarded as tight if the pressure drop during the test time is not more than 10 % of
the calculated initial value (Figure G).
• After the test time has passed, the air channel sealed airtight at the opposite end is opened.
The air must escape abruptly!
• Remove compressed air tester with test needle.
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Fig. E
E
C
B
Fig. F
D
A
B
made in Switzerland
Art. no 142.475
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Fig. G