Rotary piston gas meters have been manufactured since 1930 by Aerzener Maschinenfabrik, one of the largest and oldest manufacturers worldwide. The basis for the design of the gas meter series results from many years of experience and continual dialogue with the end users, as well as using the harmonized EU-standards which will apply to all installations within the European Market. They are manufactured in accordance wiht the Aerzen tradition for quality corresponding to the quality assurance system, certified to DIN ISO 9001 and as per pressure device guideline DGRL 97/23/EG.

The Aerzener gas meters comply with the Measuring Instrument Directive 2004/22/EC (MID).

Mode of operation

Rotary piston gas meters operate according to the positive displacement principle. They are used for metering gas in closed piping systems. A pressure difference between the inlet and outlet of the gas meter produces a driving torque on the rotary pistons. Once the driving torque exceeds the inertia of the rotors, they start rotating. During rotation, the cavities formed between the rotors and the cylinder housing fill and discharge with a volume of gas. Therefore, the rotation of the pistons is a value for the gas which has flown through. The rotation is transmitted via an adjusting gear to the counter, it records the gas volume that has passed across the gas meter in actual cubic meters. The rotors turn very freely, because no metal contact takes place within the measuring chamber. Measuring starts at Δp< 0.1 mbar and Q~1/1000 Qmax.

More flexibility by new counter design

The Aerzen rotary piston gas meters are equipped with a proven double roller type counter, which enables upon commissioning an adjustment to the flow direction by the customer without intervention of the counter. Consequently, less storing time is necessary and costs of short-term modifications regarding specific projects can be avoided.

The adjustment at site to the requested flow direction can be effected easily and without use of tools. The counter provides two displays working in opposite direction which are covered by a shield when delivered. After determination of the flow direction, the cover is removed and the corresponding display becomes visible. If necessary - the counter head can be turned by 90° when unfastening 2 hexagon socket screws.

Advantages:

• Largest series of all competitors up to G 4000 (6500 m³/h)
• In series HTB design 5 bar operating pressure (G 40 - G 400)
• Extended measuring range up to 1:160
• Guaranteed measuring precision and repeatability within the calibration validity
• Reduced assembly dimensions (3 x DN possible)
• Minimum maintenance, oil change intervals are 16 years on gas streams with utmost purity
• Double roller type counter in series makes change of the flow direction at site possible by the customer
  
• No straight inlet or outlet length required compared to turbine wheel counter
• Pressure and temperature connections are available in the housing on both sides
• Flexible customer-orientated solutions by additional equipment