Technical details
LD
S
8.270
Leak monitoring system
s
Leak monitoring: Checking the plan
t
Procedure
Test requirement
s
The basic safety technical requirements are set out in th
e
Technical Rules for
flammable Fluids – TRbF/TRBS. The lega
l
provisions governing water usage are governed by the Germa
n
Water Resources Act (Wasserhaushaltsgesetz – WHG) and the
ordinance dealing with plants which handle water-hazardou
s
substances - VAwS – as well as the regulations implementing
the VVAwS.
Standard procedures for testing TRbF 620 8 (technica
l
rules for flammable fluids)
Standard procedures for tanks and piping
Section 1.23 Double-walled pipin
g
(1) No. 1.21 applies. Connections (see Number 1.21, Par. 5) d
o
not need to be exposed for the pressure test however
.
(2) In as far as no connections to the double-walled piping ar
e
made on site, the construction and pressure test by the
technical expert can be dispensed with
.
(3) The test pressure for the test on the surveillance space de-
pends on that given in the approval for the leak detector.
A pressure test of the inner pipe is not necessary if the test
pressure for the surveillance space is at least that for th
e
inner pipe and a certificate from an expert firm can be pro
-
vided for the construction and pressure test of the inner
pipe
.
Tightness tes
t
The double-walled piping is prefabricated and tested at the
factory. If piping configured and put together ex works is used
,
Pos. (2) applies. If the pipes are laid in one piece, as is the
general rule, the tightness of the connection fittings installed
on site must be tested with test pressure in the surveillance
space
.
The level of test pressure depends on the leak detector which
is connected and in the case o
f
–
a vacuum leak detector is max. operational piping
pressure x 1.3, but at least 5 bar
– with a positive pressure leak detector max. monitoring
pressure in the surveillance space x 1.3, but at least 5 bar.
The construction of the connection fittings, their material and
joining methods are a system component of the approval. The
y
comply with the most recent regulations. The pressure test of
the inner pipe is not necessary since the double-walled pipin
g
has already undergone a tightness test at the factory.
Acceptance test, repeat testin
g
The acceptance test or the repeat tests are dealt with in Sec-
tion 2 of the TRbF 620. According to this, the tightness test for
the double-walled piping with a leak detector is replaced by a
function test of the leak detector equipment
.
The test intervals are set out in the VAwS. Repeat tests are t
o
be carried out after 5 years (in protected areas after 2.5 years).
§§ 62/63 WHG also refers to the need to comply with the
legislation of the Federal State involved. In the regulations for
plants - VVAwS -, here, e.g. in Bavaria, it stands in Par. 18.1 o
f
the VVAwS that leak detectors must be subjected to a function
test at least once a year. The function test is to be carried out
by specialist personnel or by an accredited expert firm.
31.03.2026 Subject to technical changes. Page 31
