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Technical Product Information

ROTARY DISPLACEMENT METER RMG 132-A

RMG Messtechnik GmbH

ROOTTARY DISPPLAACEEMENTT MMETER RMG

2

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

Application

• 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 fl ow directions.• No inlet or outlet pipes are required for operation.• Can also be used in the case of intermittent gas withdrawal.

Method of operation

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 fl owed 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 force-controlled by precision gears located outside of the measu-ring chamber.

In the further course of the rotation of the pistons, the two sections of the measuring chamber of the rotary displace-ment meter are periodically fi lled 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 compart-ment 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 po-sition for installation and direction of fl ow of the gas meter.

LF and HF pulsers can be fi tted in the totalizer. They gene-rate an electric volume pulse which is further processed by appropriate supplementary equipment. The rotary displace-ment meter starts to operate at a pressure drop of less than 0.1 mbar and a fl ow rate of less than < 1/1000 Qmax.

Testing / Gas meter calibration

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

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

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 fi lter-purifi ed gases with a solids grain size of less than 50 μm are permis-sible. It is recommended that a fi lter or at least a start-up screen be installed.The gas meter is supplied without oil. As soon as the un-pressurized gas meter has been installed in the pipeline, the cover compartments are to be fi lled with oil.This has to be done gradually in order to avoid fi lling 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.

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ROTARY DISPLACEMENT METER RMG 132-ACapacity data

CAPACITY DATA

SizeDN

(inch)Qmax

m³/hV

dm³

Qmin

m³/hPulse

Measuring range LF HF1:20 1:50 1:65 1:80 1:100 1:160 Pulses/m³ Pulses/m³*

G 4050(2“)

650.67

3 1.3 1 0.8 0.6 - 10 6000

G 65 100 5 2 1.6 1.3 1 0.6 10 6000

G 10080(3“)

160 1.07 8 3 2.5 2 1.6 1 1 3750

G 160 250 1.67 13 5 5 3 2.5 1.6 1 2400100(4“)

NOTE: Standard - measuring range 1:50 * Approx. values; see the pulser plate for the precise pulse value.

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

Average pressure loss curve

Erro

r of m

easu

rem

ent %

Flow rate m /h3Qmin Qt

QmaxG

0

-2

-1

+1

+2

Pres

sure

loss

mba

r

Flow rate m /h3

Qmin QmaxG

Natural gas

Air

2

0

1

3

4PRESSURE LOSS

SizeAir

(ρ=1.2 kg/m³)Natural gas

(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

(Average pressure loss in mbar at Qmax)

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ROTARY DISPLACEMENT METER RMG 132-ADimensions and weights, taps

DIMENSIONS AND WEIGHTS

Size DN(inch)

A B C D E Weight Flanges withthreaded holes

mm kg DIN 2501 ANSI B 16.5

G 4050(2“)

350 230 120 180

- -

4x M16 4x 5/8171 13

G 65- -

171 13

G 100 80(3“)

420 265 155 180171 16

8x M16 4x 5/8241 22

G 160 528 320 208 210

241 23

100(4“)

241 23PN16

8x 5/88x M16

300 29PN25

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

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

Pressure taps

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

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ROTARY DISPLACEMENT METER RMG 132-ATechnical data

RMG 132-AMaterial AluminiumSize G 40 – G 65 – G 100 – G160Pressure rating PN 16, ANSI 150Installation position / Direction of fl ow Horizontal or vertical / universalInstallation No inlet or outlet section requiredOperating temperature range -40°C to +60°CDesign Adapted to DIN EN 12480

Approvals- PTB approval up to 1 :160- EC approval- other international approvals

Degree of protection IP 65MaterialsCasingPistonsGears

Aluminium alloyAluminium alloySteel, hardened and ground

Type of connection Flanges with threaded holes

Connecting dimensionsDIN 2501ANSI B 16.5 RF

Variants offl anged ends

PN 16 – DIN 2501ANSI150 – ANSI B 16.5 RF

Measuring ranges 1: 50 (standard) up to 1 : 160 (option)

Accuracy< 2% at Qmin

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

Repeatability < ±0.1%Pressure loss See table on page 3Overloading For a short time up to 1.25 Qmax

Rate of pressure variations < 0.5 bar/sMeasuring 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 optionOil-level gauge On the front (standard), on both sides as option

Mechanical totalizer

- Double totalizer as standard- 8-digit index in m3 (standard) or ft3 (option)- Optical start-up display- Can be universally adapted to the direction of fl ow; a representative of the weights and measures offi ce need not be present on this occasion.

TEMPERATURE TAPS PRESSURE TAPS

Rotarydisplacement meter Thread

Installation variants for thermowells

2x inlet 1x inlet 1x inlet1x outlet Thread Seal of

threaded hole

Al / PN16M14 x1.5 X

X X M10 x1Screw fi tting with

sealing cone for pipes with dia. Ø6G 1/2 * -

Al /ANSI1503/4 NPT -

X X 1/4 NPT Screw plug 1/4 NPTG 1/2 * -

* on request

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ROTARY DISPLACEMENT METER RMG 132-A

Flow variants

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

Flow variants

Pulse transmitters

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

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

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

Variants - 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

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ROTARY DISPLACEMENT METER RMG 132-A

Ordering information (example)

Device designation:

Device designation, accessories

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

Type

ORDERING INFORMATION

Casing material Al

Size G40; G65; G100; G160

Nominal diameterDN 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 / Direc-tion of fl ow

SU - perpendicurlarly downwards (standard, if not indicated otherwise)

WR - horizontally to the rightSO - perpendicurlarly upwardsWL - 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

Casi

ng m

ater

ial

Size

Nom

inal

dia

met

er

Pres

sure

ratin

g /

Flan

ged

ends

Over

all l

engt

h

Mea

surin

g ra

nge

Stat

e in

whi

ch s

uppl

ied

- Pos

ition

for i

nsta

llatio

n /

Dire

ctio

n of

fl ow

Puls

e tra

nsm

itter

s

Ther

mow

ells

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

Status 11/2008 Rotary Displacement Meter RMG 132-AWe reserve the right for technical changes

WÄGA Wärme-Gastechnik GmbHOsterholzstraße 45D-34123 KasselPhone +49 (0)561 5007-0Fax +49 (0)561 5007-207

RMG Gaselan Regel + Messtechnik GmbHJulius-Pintsch-Ring 3D-15517 FürstenwaldePhone +49 (0)3361 356-60 Fax +49 (0)3361 356-836

CANADA

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

USA

Mercury Instruments LLC3940 Virginia AvenueCincinnati, Ohio 45227Phone +1 513 272-1111Fax +1 513 272-0211

GERMANY

RMG Regel + Messtechnik GmbHOsterholzstraße 45D-34123 KasselPhone +49 (0)561 5007-0Fax +49 (0)561 5007-107

RMG Messtechnik GmbHOtto-Hahn-Straße 5D-35510 ButzbachPhone +49 (0)6033 897-0Fax +49 (0)6033 897-130

ENGLAND

Bryan Donkin RMG Gas Controls Ltd.Enterprise Drive, HolmewoodChesterfi eld S42 5UZ, EnglandPhone +44 (0)1246 50150-1 Fax +44 (0)1246 50150-0

POLAND

Gazomet Sp. z o.o.ul. Sarnowska 263-900 Rawicz, PolenPhone +48 (0)65 54624-01 Fax +48 (0)65 54624-08

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