Keep this manual easily accessible for all users .
Ask for a written approval of the manufacturer for
all cases not planned in this instruction manual .
Please respect all national rules for installation,
operation and service of gas meters .
1 Characteristics
Delta QD meters are designed to measure gases
of the 1st, 2nd and 3rd gas families as speci-
fied in EN437 as well as various filtered and non-
corrosive gases .
General characteristics: See Annex 1
2 Packing
• The meter, depending on the size or version is
delivered:
• In a cardboard box, protected by carton inserts .
The packing shall contain the filling lubricant, plugs
for the installed transmitters and this instruction
manual .
2.1 Storage
If the meter is not going to be used immediately,
it should be stored under cover in a clean, dry
environment, in the horizontal position .
The caps fitted in the inlet and outlet pipe must
stay in place until installation .
2.2 Handling
The meter is delivered without lubricant in cov-
er . Before shipping or handling, ensure that the
lubricant has been thoroughly drained from the
front cover to prevent spillage into the measuring
chamber .
3 Installation
3.1 General
Due to the volumetric principle of the Delta QD
meter, its metrology is not influenced by the in-
stallation conditions . Nevertheless the respect of
the following rules will insure the best use of your
meter:
4
Recommended installation: See Annex 2
Check visually that the meter has not been dam-
aged during transport .
• No welding is allowed with meter installed .
• The meter should be installed with the impellers
horizontal . Allowed deviation: +/- 5° .
• Never install a meter at a low point in the piping
where the meter could be subject to the accu-
mulation of water or particles .
• If Teflon tape is used to tight threaded joint then
the best attention must be taken to avoid intro-
ducing tape in the measuring chamber .
• The meter should be installed without stress in
the piping .
• The use of a filter, placed upstream of the me-
ter, is advisable in gas with high particulate con-
tent . See § 3 . 2 .
Before installation:
• The piping upstream of the meter should be
free of dust .
• Remove the protective caps .
• Ensure that the direction of gas flow corre-
sponds with the arrow situated on the meter
body .
• Check that the impellers turn freely .
3.2 Filtration
Rotary meters work better if there are no particles
within the gas . It is advisable therefore to filter the
gas upstream of the meter . Recommended level
of filtration is 100 μm or better .
While the meter is in service, periodically check
the cleanliness of the filter, especially in the case
of a new installation or after work has been per-
formed on the upstream piping .
For installation with flow direction from bottom to
top a particular attention has to be taken to the
filtering conditions to avoid that accumulation of
dust downstream of the meter may come back
into the meter . For example a second filter can
be installed downstream of the meter .
3.3 Lubrication
3.3.1 General
Choose the lubricant according to the operating
conditions . This lubricant should be neutral and
non detergent . Important:
• A lack of lubricant could cause premature wear
of the meter .