Installation and Commissioning
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Manual TRZ 04 · EN04 · February, 1st 2017
25
2 Installation and Commissioning
2.1 Installation
Notice
Any components affecting the gas flow must be avoided directly upstream of
the turbine meter (see DVGW Guideline G 492 II
1)
and PTB Guideline G 13
2)
.
An inlet pipe of a minimum of 2 x DN is required upstream of the RMG TRZ
04 turbine meter. The inlet pipe must be designed as a straight pipe section
of the same nominal diameter as the gas meter. If there is a heavy flow
disturbance, it is necessary to use flow straighteners (see table on next
page). A pipe or fitting (bend) of the same nominal diameter as the gas meter
and an overall length of 2 x DN must be installed downstream of the gas
meter.
Temperature measuring instruments may only be installed at a distance of 1
x DN or in the case of nominal diameters of
DN 300 at a minimum distance
of 300 mm.
If there are flow disturbances (e.g. due to a gas pressure regulator) upstream
of the inlet pipe, it is also necessary to use a perforated-plate straightener.
You can use perforated-plate straighteners complying with ISO 5167-1 or of
type RMG LP-35, the latter resulting in a pressure loss which is 2.5 times
lower than that of the standardized flow straightener.
The opening angle of reducers or expansion fittings installed upstream of a turbine
meter of type TRZ 04 or TRZ 04-K must not exceed 30°.
In order to obtain precise measurement results, the turbine meter must be installed in
the gas line in such a way that no seals protrude from the flanges into the pipeline.
1)
can be ordered at DVGW, Josef-Wirmer-Str. 1-3, D-53123 Bonn (www.dvgw.de)
2)
can be ordered at PTB, Bundesallee 100, D-38116 Braunschweig (www.ptb.de)
2 DN
2 DN
1 DN
Perforated-plate straightener
d
e
d
DN
DN
d = e = 0.13 DN
•
LP-35 perforated-plate straightener
