Dresser Turbine Meter

[Brochure]

Dresser Turbine gas meters, ranging from 2" G40 up till 12" G 4000 for pressures up till 100 bar. All meters are based on the concept of the Removable Meter Cartridge (RMC). This unique feature enables the owner/operator to change the characteristics of the meter on-site. For meters up to 8", four types of RMC’s are available to offer maximum modular flexibility in terms of minimum capacity, maximum capacity, pressure loss, and G-rating.

The cartridges can be pre-calibrated by certified test institutes, and thus upgrades in performance or functionality of the meters can be done easily and locally. The recalibration of meters becomes a matter of hours, since cartridges can be exchanged on site with new pre-calibrated cartridges, reducing logistical efforts to a minimum and still keeping the quality and performance at the highest level. The weight of the Removable Meter Cartridge is clearly significantly lower than a complete meter, meaning that “courier” transportation of the cartridge can be done rapidly and safely without complex and time consuming packing and shipping arrangements.

The length of the meter is three times the diameter and complies in full with the European directives for turbine meters. The cartridge and the turbine wheel are machined from high quality aluminium to guarantee long term stability. Optional, the cartridge can be hard-coated (anodized) to overcome wear and corrosion of the flow channels caused by dirt and dust.
By the use of a special ring, to position the cartridge in the meter body, the cross-sectional area of the cartridge is significantly larger in comparison to conventional turbine meters.

This enables to manufacture these meters with an extended maximum capacity (extended G-rating) another unique feature. As, with most of the conventional meter manufacturers e.g. a 6” is available with typically a Qmax. of 1600 m 3 /h, the 6” iMTM-CT can handle a capacity of 2500 m 3 /h. The possibility to apply one size (diameter) smaller turbine meter will not only have a positive effect on the purchase price of the meter but will also allow to use smaller meter run piping, valves, etc. and thus will reduce the size of the metering station and its building significantly.

All the critical components, including the turbine rotor and primary gears, are housed in the cartridge (RMC), making the concept quite suitable for local production and assembly. Except for the RMC, the remaining parts like meter body, external gear box, index, etc. can be manufactured locally, if required, in accordance to local directives and quality standards. Since the high quality RMC is the actual measuring mechanism, and totally independent on the meter body tolerances, the end quality of a local produced and assembled turbine meter will still meet the highest quality requirements.

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Features

Dresser Turbine Meters Design Features

Easy “on-site” maintenance by replacing the RMC with a freshly pre-calibrated new RMC of the same G-rating or alternative G-rating.
Reduced cost of repair by removing and returning-for-overhaul, the RMC only, doing away with the long and thus unacceptable lead times for conventional meter repair and overhaul.
Increased life time by using an oil system that just not only refreshes the oil in the bearings and lubricates all moving parts, but really flushes out all the dirt and dust.
Reduced sensitivity to severe gas conditions by improved protection of the main bearings against dirt and dust.

Options

Low Weight Aluminum Meter Body
Preferably the meters must be transported by a luxury car, however this is rarely common practice, simply due to the weight of the conventional steel body meters. Thus a better alternative is to use light weight materials (aluminium) for the meter body, to enable a secure transportation by a luxury car. Aluminum is already used in many countries where care and quality of transportation is not controllable due to bad road conditions in remote areas. The aluminum bodies are, in terms of strength, equivalent to the iron GGG40 meter bodies and are being certified to be suitable for all classes up to ANSI 150 or DIN PN 16. The hard anodized coating will give the meter body a superior protection against corrosion.

Optimized Bearing Construction Including Axial Load Compensation
The shock load in combination with the weight of the turbine wheel will cause impacts between the tiny balls and the inner/outer ring of the ball bearing. This is the starting point of an excessive wear, resulting in increased friction and consequently a shift in accuracy. Eventually these bearings will collapse. The use of low weight plastic turbine wheels is not considered as a serious engineering solution, since their performance in relation to accurate measurement is very poor. In addition, the impurities within the gas will degrade the plastic wheel and thus will significantly affect the accuracy of the meter. To reduce the forces acting on the main bearings, the front main bearing (larger than the rear bearing to overcome the axial load) is positioned exactly in the vertical centre line of the turbine wheel, meaning that the resulting forces on the tiny rear bearing are eliminated. This is another unique feature and major improvement.

Dirt Protection and Full Flushing Oil System
In order to keep the bearings in proper condition, it is essential to flush out the dirt (dust) and refresh the oil on a regular time interval. Turbine meters, being equipped with commercially called “lubricated for life” bearings are not recommended at all – except in case of vertical installation – since dust within the gas will slowly accumulate over time and degrade the performance of the bearing and thus the accuracy of the meter. As clearly stated within the German law, meters without lubrication must be re-calibrated at least once per 8 years, while meters fitted with lubrication require re-calibration only once per 12 years.

One Twist and a click Multi Functional Coupling
To eliminate restrictions to future upgrades both the Dresser Turbine Meters and Series C Rotary Meters are equipped with a hybrid magnetic coupling. Using a special designed magnet inside the meter, the reading of the meter can be changed on site from “mechanical” (magnet is used to drive the follower magnet of the mechanical index) to “electronic” (magnetic field orientation is used to activate pulse wires for detecting the rotation, direction and position of the turbine wheel). The index and its functions can be exchanged with just “one twist and a click”. This means that the most basic meter version is already prepared for upgrades to a fully sophisticated electronic meter including conversion (PTZ) and communication features (GSM, ISDN, PSTN, Ethernet, etc.).

HF Sensor combined with Isolated Thermowell
Dresser Turbine Meters can be fitted with multiple High Frequency Sensors. These optional sensors can also be fitted to the meter at a later stage, without removing the meter or the cartridge from the installation. The sensor is designed and approved in accordance with ATEX, FM and CSA.

Technical Data

Dresser Turbine Meters Technical Data

Applications:
Media: natural gas, town gas, propane, inert gases. Others on request
Industry: Gas supply, heating manufacturers, chemical industry.

Pressure ratings:
• Pressure ratings for PN10/16 and up to ANSI 600.
• Various flanges are available on request.
(DIN Flanges, ANSI Flanges, JIS Flanges and others

Nominal diameters:
50 mm (2”) to 300 mm (12”.

Measuring range:
20 : 1 minimum or better at atmospheric conditions up to 50 : 1 at higher densities.

Flow rates:
8 m3/h up to 6500 m3/h
Repeatability: better than 0,1 %

Measuring accuracy:
0,2 Qmax to Qmax : ± 1 % or better
Qmin to 0,2Q max : ± 2 % or better

Temperature range:
Aluminium Standard : -25°C to + 60°C
Steel Standard -10°C to + 60°C, wider range on request

Meter Data table

Dresser Electric Turbine Gas Meter brochure

Dresser Turbine Gas Meter Extended Maximum Capacity brochure