Model 750 Gas Meter
Installation, Commissioning and Maintenance Manual
Page 3 of 17
© Gyr
17-May-2016
Due to continuous product development the details above are subject to change without notice. Whilst Gyr has taken all reasonable
care in reviewing the information in this document, Gyr makes no representations in respect of, gives no guarantees or undertakings in
relation to, and to the maximum extent permitted by law, excludes all warranties in relation to, the accuracy or completeness of the information
in this document. Prospective users of this information should make their own enquiries as to its accuracy and reliability.
GENERAL INFORMATION
The Model 750 is a compact, aluminium case, slow
revving high capacity 2 litre per cycle gas meter
designed to minimise the speed of internal
components to reduce wear and ensure long term
accuracy retention. The Model 750 meter runs 60 %
slower than a 1.2 litre per cycle gas meter.
The 750 has a designed capacity of 6m3/hr of air at
125 Pa pressure drop (7.5 m
3
/hr of Natural Gas
SG0.62), a standard proven in Australia and
worldwide, to give durable meters which maintain high
levels of accuracy for many years.
SPECIFICATIONS
Connections:
Meter boss threads vertical
inlet/outlet 10 Light 1” to BS746 1987 at 152mm (
6” ) centres. 1” 10 Lt. to ¾” BSP Cap Nut and
Liner set available part number SK5.
Gases:
Natural gas, liquefied petroleum gas
(LPG), simulated natural gas (SNG), tempered
liquefied petroleum gas (TLP), town gas (TG),
butane, propane, nitrogen, and air. For gases not
listed please consult Gyr.
Meter Accuracy:
The high resolution adjustable
tangent allows for the Model 750 to be supplied
with a narrow band of accuracy, excellent
turndown ratio and superior high level of accuracy
at low flow rates.
The 750 is built for a service life of many years
and to an initial accuracy of better than +/- 1%
and typically supplied with limits of +/- 0.75% ex-
factory.
Meter Life:
Ageing life tests have provided
performance results that demonstrate the long life
and high accuracy for in excess of 20 million
cycles.
Exceeds the endurance testing requirements of
both the European Standard EN1359:1999 and
the Australian Gas Association AG702 which are
in excess of the endurance testing requirements
as specified in OMIL Recommendation 31.
Pressure
Absorption:
The
slow
revving
operation (2 litres / cycle), the low friction valve
assembly and large passage ways provide the
750 with low pressure absorption of 125 Pa at 6
m3/hr air ensuring long term accuracy retention
and low wear.
Cyclic Capacity:
0.002 cubic metres (2 litres/rev)
or 2 deci-metres per revolution.
Maximum Working Pressure:
10 - 50 kPa
standard operating pressure.
Index Drive:
Magnetically driven low mechanical
wear index drive
Index Reading:
8 wheels, 5 whole cubic metres
and 3 decimal places 99999.999 cubic metres.
White numbers on a black wheel for whole cubic
metres and white numbers on a red wheel for the
3 decimal places.
Anti-Fogging Index:
Index is coated with a
hydrophilic coating to prevent fogging of the meter
index.
Bar Code:
EAN Code 128 Specification.
Type:
Front read or top read versions available
Meter Accuracy:
The 750 is built for a service life
of many years and to an initial accuracy within the
limits of +/- 0.75%.
Case Construction:
Pressure die cast aluminium
alloy CA313 to AS1874-1988 alodine pre-
treatment followed by baked polyester powder
coat.
Corrosion Protection:
Chromate pre-treatment
of castings followed by baked polyester powder
coat for maximum corrosion protection. Provides
guaranteed 1000 hour accelerated salt spray
compliance to ASTM B117.
Operating Temperature Range:
–10 to +65
o
C.
Meter Badge:
UV Stabilised polyester badge with
serial number and customer details.
Outlet Tapping Point:
Meter outlet tapping point
screw (M4x8mm) for pressure testing or setting is
recessed to prevent accidental damage and
forward facing for easy access. Suitable for 10mm
ID (inside diameter) plastic tubing.
Security Seals:
Three red plastic (POM- Acetal)
seals to prevent undetected unauthorised access.
Adjustable Tangent:
High resolution self locking
adjustable tangent allows precision fine tuning for
both meter accuracy and trend.
