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SERVING THE GAS INDUSTRY WORLDWIDE

Technical Product Information

ROTARY RO OTARY DISP DISPLACEMENT PLA ACE EMENTT M METER ETER RMG 132-A

RMG Messtechnik GmbH


ROTARY DISPLACEMENT METER RMG 132-A Application, method of operation, testing, maintenance

2

Application

Testing / Gas meter calibration

• RMG 132-A rotary displacement meter for volumetric gas measurement in gas distribution stations and in domestic, administrative and industrial buildings. • Suitable for use with all non-corrosive gaseous media, such as natural gas, propane, butane, nitrogen, air, etc. • For vertical or horizontal installation in both flow directions. • No inlet or outlet pipes are required for operation. • Can also be used in the case of intermittent gas withdrawal.

The rotary displacement meters correspond to DVGW, PTB and EC regulations and other international and national regulations of various countries. In our staterecognized testing laboratory for gas measuring devices, each rotary displacement meter is tested in operational condition and checked for compliance with the error range. It is then provided with an official seal which identifies it as being approved for custody transfer metering.

Method of operation

The quality details resulting from the strength and leak tests are documented in accordance with national and international standards.

The rotary displacement meter is a gas meter which measures the volume of gas and operates on the displacement principle. It records the gas volume at actual line conditions (i.e. volume at measurement conditions) which has flowed through the gas meter. A downstream volume corrector can be used to convert this volume into the volume at base conditions. The rotary displacement meter consists of the actual measuring element and a totalizer to display the volume at measurement conditions. When the gas decreases, there is a pressure drop between the meter inlet and outlet which produces a torque at the two rotary pistons. As soon as this torque exceeds the holding torque of the rotary pistons, the pistons start to rotate. The rotation of the pistons is forcecontrolled by precision gears located outside of the measuring chamber. In the further course of the rotation of the pistons, the two sections of the measuring chamber of the rotary displacement meter are periodically filled and evacuated. There is a non-contact seal between the two measuring chamber sections which is achieved by minimum gaps between the rotary pistons themselves and between the rotary pistons and the casing. The rotational movement of the pistons is transferred through a magnetic coupling to the pressureless compartment of the totalizer where the rotations are added and then displayed on a digital index as volume (m3, ft3). The totalizer is installed rotatably and can be adjusted to the relevant position for installation and direction of flow of the gas meter. LF and HF pulsers can be fitted in the totalizer. They generate an electric volume pulse which is further processed by appropriate supplementary equipment. The rotary displacement meter starts to operate at a pressure drop of less than 0.1 mbar and a flow rate of less than < 1/1000 Qmax.

Installation and maintenance The rotary displacement meter is to be installed in the pipeline with minimum stress using appropriate seals and screws according to standards. No base is required for the gas meter. During installation, the rotary displacement meter is to be aligned using a spirit level, so that the piston axes are in a horizontal position.This ensures uniform lubrication of the gear parts in the front and rear covers. For troublefree operation of the gas meter, only filter-purified gases with a solids grain size of less than 50 μm are permissible. It is recommended that a filter or at least a start-up screen be installed. The gas meter is supplied without oil. As soon as the unpressurized gas meter has been installed in the pipeline, the cover compartments are to be filled with oil.This has to be done gradually in order to avoid filling beyond the sight-glass area. When commissioning the gas meter, pressure shocks are to be avoided. The process should be performed slowly. Maintenance of the gas meter is limited to an oil-level check which is to be performed approximately once a year. For this purpose, the rotary pistons must be at rest. If the oil level falls below the centre mark of the sight glass, oil has to be topped up. We would recommend using the oil types Shell Tellus oil 10 or BP Energol HLP 10 or a comparable oil with a kinematic viscosity of 10 mm2/s at 40°C. The totalizer is completely maintenance-free. The gas meter can also be used in outdoor installations if an appropriate protection against the weather is provided. For special information about installation and maintenance, see the Operating and Maintenance Instructions 132.20.


ROTARY DISPLACEMENT METER RMG 132-A Capacity data CAPACITY DATA Qmin Size

G 40

DN

Qmax

V

(inch)

m³/h

dm³

65

50

LF

HF

1:20

1:50

Measuring range 1:65

1:80

1:100

1:160

Pulses/m³

Pulses/m³*

3

1.3

1

0.8

0.6

-

10

6000

5

2

1.6

1.3

1

0.6

10

6000

0.67

(2“)

G 65

Pulse

m³/h

100

3 G 100

80

160

1.07

8

3

2.5

2

1.6

1

1

3750

250

1.67

13

5

5

3

2.5

1.6

1

2400

(3“)

G 160

100 (4“)

Error of measurement %

NOTE: Standard - measuring range 1:50

* Approx. values; see the pulser plate for the precise pulse value.

+2 +1 0 -1 G

Qmax

-2 Qmin

Qt

Flow rate m3/h

Average error curve (Qt - as a function of the measuring range)

Pressure loss mbar

PRESSURE LOSS

4 Air

3 2

Natural gas

1 0

Qmin

G Flow rate m3/h

Average pressure loss curve

Air

Natural gas

(ρ=1.2 kg/m³)

(ρ=0.83 kg/m³)

G40

1.5

1.0

G65

3.3

2.3

G100

3.6

2.5

G160

3.4

2.4

Size

Qmax

(Average pressure loss in mbar at Qmax)


ROTARY DISPLACEMENT METER RMG 132-A Dimensions and weights, taps DIMENSIONS AND WEIGHTS Size

G 40 G 65

4

G 100

DN (inch)

50 (2“)

80

A

B

C

D

mm

350

420

230

265

120

155

100

528

320

208

Weight kg

180

180

(3“)

G 160

E

210

(4“)

-

-

171

13

-

-

171

13

171

16

241

22

241

23

241

23

300

29

Flanges with threaded holes DIN 2501

ANSI B 16.5

4x M16

4x 5/8

8x M16

4x 5/8

PN16 8x M16 PN25

8x 5/8

8x M20

NOTE: The overall lengths greyed out have rings on both sides.

1 - Totalizer,

2 - Measuring element,

3 - Pressure tap,

4 - Temperature tap,

5 - Pulser connection,

6 - Oil-level gauge

Temperature taps

Pressure taps

The temperature taps are required for installing thermowells for resistance thermometers. They are located on the inlet and outlet flanges of the gas meter. Note: Standard – without thermowells; threaded holes sealed with screw plugs.

Pressure taps are required to determine the pressure at measurement conditions when a volume corrector is connected or for differential pressure measurement via the gas meter. The gas meter has one pressure tap on each of the inlet and outlet flanges.


ROTARY DISPLACEMENT METER RMG 132-A Technical data RMG 132-A Material

Aluminium

Size

G 40 – G 65 – G 100 – G160

Pressure rating

PN 16, ANSI 150

Installation position / Direction of flow

Horizontal or vertical / universal

Installation

No inlet or outlet section required

Operating temperature range

-40°C to +60°C

Design

Adapted to DIN EN 12480 - PTB approval up to 1 :160

Approvals

- EC approval

5

- other international approvals Degree of protection

IP 65

Materials Casing

Aluminium alloy

Pistons

Aluminium alloy

Gears

Steel, hardened and ground

Type of connection

Flanges with threaded holes DIN 2501

Connecting dimensions

ANSI B 16.5 RF

Variants of

PN 16 – DIN 2501

flanged ends

ANSI150 – ANSI B 16.5 RF

Measuring ranges

1: 50 (standard) up to 1 : 160 (option) < 2% at Qmin

Accuracy

< 1% at Qmax (factory-provided: 0.5%)

Repeatability

< ±0.1%

Pressure loss

See table on page 3

Overloading

For a short time up to 1.25 Qmax

Rate of pressure variations

< 0.5 bar/s

Measuring taps

Pressure and temperature taps are located in the inlet and outlet of the meter casing.

Pulse transmitters

1x LF(reed), further LF or HF (NAMUR) pulsers as option

Oil-level gauge

On the front (standard), on both sides as option - Double totalizer as standard - 8-digit index in m3 (standard) or ft3 (option)

Mechanical totalizer

- Optical start-up display - Can be universally adapted to the direction of flow; a representative of the weights and measures office need not be present on this occasion.

TEMPERATURE TAPS Rotary displacement meter

Thread M14 x1.5

2x inlet

1x inlet

1x inlet 1x outlet

Thread

Seal of threaded hole

X

X

M10 x1

Screw fitting with sealing cone for pipes with dia. Ø6

X

X

1/4 NPT

Screw plug 1/4 NPT

X

Al / PN16 G 1/2 *

-

3/4 NPT

-

G 1/2 *

-

Al /ANSI150

* on request

PRESSURE TAPS

Installation variants for thermowells


ROTARY DISPLACEMENT METER RMG 132-A Flow variants

Flow variants

6

The position for installation or direction of flow can subsequently be changed by simply turning the totalizer or the totalizer cap. For further details, see the Operating and Maintenance Instructions 132.20.

Pulse transmitters

HF

The totalizer can optionally be fitted with one or more pulse transmitters. Signals are picked up through a lateral plug.

Variants

Types LF - reed switch, polarity-independent - operating voltage U = 5-24 V DC - switching current, max. I = 10 mA

- NAMUR slot-type initiator, polarity to be observed - operating voltage U = 8 V DC - current input approx. 3 mA

- without pulse transmitter - 1 x LF (standard) - 1 x LF, 1 x HF - 1 x LF, 2 x HF - 2 x LF - 2 x LF, 1 x HF


ROTARY DISPLACEMENT METER RMG 132-A Device designation, accessories

Ordering information (example) Device designation:

Al

Size

G40; G65; G100; G160

Nominal diameter

DN 50 (2˝ ) DN 80 (3˝ ) DN 100 (4˝)

Pressure rating/ Flanged ends

PN16; ANSI150

Overall length E

See table

Measuring range

1:20; 1:50; 1:65; 1:80; 1:100; 1:160

State in which supplied Position for installation / Direction of flow

SU - perpendicurlarly downwards (standard, if not indicated otherwise) WR - horizontally to the right SO - perpendicurlarly upwards WL - horizontally to the left

Pulse transmitters

1x LF, 1x LF 1x HF, 1x LF 2x HF, 2x LF, 2x LF, 1x HF

Thermowells

0; 1; 2* * Type of installation: 1x inlet, 1x outlet 2x inlet

Accessories • Thermowell - Integral thread M14x1.5 G 1/2 – on request Connection of the temperature sensor G1/4 - Integral thread 3/4 NPT Connection of temperature sensor on request

• Start-up screen (mesh size 0.4 mm) • Volume corrector • Fastening bracket for Volume corrector • Three-way check valve

Thermowells

Pulse transmitters

Measuring range

Overall length

Nominal diameter

State in which supplied - Position for installation / Direction of flow

Casing material

Pressure rating / Flanged ends

ORDERING INFORMATION

Size

Casing material

Type

RMG 132-A - Al - G65 - DN50 - PN16 - 171 - 1:80 - SU - 2x NF - 2x (inlet)

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SERVING THE GAS INDUSTRY WORLDWIDE

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WWW.RMG.COM . G.CO

GERMANY RMG Regel + Messtechnik GmbH Osterholzstraße 45 D-34123 Kassel Phone +49 (0)561 5007-0 Fax +49 (0)561 5007-107

WÄGA Wärme-Gastechnik GmbH Osterholzstraße 45 D-34123 Kassel Phone +49 (0)561 5007-0 Fax +49 (0)561 5007-207

RMG Messtechnik GmbH Otto-Hahn-Straße 5 D-35510 Butzbach Phone +49 (0)6033 897-0 Fax +49 (0)6033 897-130

RMG Gaselan Regel + Messtechnik GmbH Julius-Pintsch-Ring 3 D-15517 Fürstenwalde Phone +49 (0)3361 356-60 Fax +49 (0)3361 356-836

ENGLAND

CANADA

Bryan Donkin RMG Gas Controls Ltd. Enterprise Drive, Holmewood Chesterfield S42 5UZ, England Phone +44 (0)1246 50150-1 Fax +44 (0)1246 50150-0

Bryan Donkin RMG Canada Ltd. 50 Clarke Street South, Woodstock Ontario N4S 7Y5, Canada Phone +1 519 53-98531 Fax +1 519 53-73339

POLAND

USA

Gazomet Sp. z o.o. ul. Sarnowska 2 63-900 Rawicz, Polen Phone +48 (0)65 54624-01 Fax +48 (0)65 54624-08

Mercury Instruments LLC 3940 Virginia Avenue Cincinnati, Ohio 45227 Phone +1 513 272-1111 Fax +1 513 272-0211

We reserve the right for technical changes

Status 11/2008

Rotary Displacement Meter RMG 132-A


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