wbz08_manual_en by neue formen GmbH & Co. KG

Vortex Meter WBZ 08 / WZ 07

OPERATING INSTRUCTIONS

Serving the Gas Industry Worldwide

STATUS MAY 2011

by Honeywell

...............................................................................................................................................................................................................

Note: Unfortunately, paperwork does not automatically update itself but technical developments are constantly being made. Therefore, we reserve the right to change the descriptions and statements contained in our operating instructions without prior notice. However, you can conveniently download the most recent version of this manual (and those of other devices) from our website www.rmg.com.

RMG Messtechnik GmbH Otto-Hahn-Str. 5 35510 Butzbach (Germany) Fax: +49 (0)6033 897-130 E-mail: Messtechnik@Honeywell.com

Phone numbers: Switchboard: +49 (0)6033 897-0 Customer Service: +49 (0)6033 897-127 Spare Parts: +49 (0)6033 897-173

CONTENTS

DESCRIPTION ...................................................................................................... 1 WBZ 08 .................................................................................................................................... 1 Introduction ....................................................................................................................................... 1 Configuration..................................................................................................................................... 1 Typical Application-Specific Fluids..................................................................................................... 2 Method of Operation ......................................................................................................................... 2 Construction...................................................................................................................................... 3 Features ............................................................................................................................................ 3 Instrumentation ................................................................................................................................. 4 Custody Transfer Metering ................................................................................................................ 4 Pressure Loss: ................................................................................................................................... 5 Field of Application – Table 1 ............................................................................................................ 5 Nominal Diameter and Measuring Range .......................................................................................... 6 Dimensions ....................................................................................................................................... 8

WZ 07 ...................................................................................................................................... 9 Introduction ....................................................................................................................................... 9 Special Features ................................................................................................................................ 9 Fields of Application .......................................................................................................................... 9 Specifications .................................................................................................................................. 10 Measuring Ranges – Table 2 (delta-shaped body)............................................................................ 10 Pressure Loss: ................................................................................................................................. 11 General Drawing .............................................................................................................................. 12 Dimensions – Table 3 ...................................................................................................................... 12 WZ 07-S Variant .............................................................................................................................. 13

Electronic System ................................................................................................................. 14 Overview ......................................................................................................................................... 14 Safety Barrier .................................................................................................................................. 15 WS 02b Measuring Amplifier for Vortex Meters............................................................................... 16

INSTALLATION .................................................................................................. 17 Metering Line with Meter ..................................................................................................... 17 Electrical Connections and Wiring ....................................................................................... 17 Wiring Diagram for Amplifiers and the Safety Barrier ...................................................................... 18

STARTUP............................................................................................................ 19 Checking the Resistance of the Thermistor Sensor ............................................................ 19 Setting the Amplification Factor .......................................................................................... 20 Rough setting .................................................................................................................................. 21 Fine setting ..................................................................................................................................... 21

Square-Wave Output Signal .................................................................................................. 22 Replacement of components ................................................................................................ 22 Oscillograms ......................................................................................................................... 23 ............................................................................................................................................................................................................... Manual WBZ 08 · EN02 · 2011-05

CONTENTS

MAINTENANCE .................................................................................................. 24 Thermistor Sensor Types TF 01 and TF 02 .......................................................................... 24 Inspection of the Thermistor Sensors .................................................................................. 25 Inspection of the Bluff Body ................................................................................................. 25

ANNEX ............................................................................................................... 26 Connector Pin Assignments of the SBWS 02b Safety Barrier ............................................. 27 Connector Pin Assignments of the WS 02b Measuring Amplifier for Vortex Meters ......... 27 Parts List for the WBZ 08 / WZ 07 Vortex Meters............................................................... 28 Working Sheet A1 ................................................................................................................. 30 Error Curve as a Function of the Reynolds Number ReD.................................................................. 30

Working Sheet A2 ................................................................................................................. 32 Characteristics of Industrial Gases .................................................................................................. 32

Working Sheet A3 ................................................................................................................. 33 Influence of Pulsation on Vortex Meters .......................................................................................... 33

Data Sheet ............................................................................................................................. 35 Certificates of Conformity .................................................................................................... 37

DESCRIPTION

Description WBZ 08 Introduction If a bluff body is located in a flowing fluid, vortices are shed on its downstream side. As early as in 1878, Kármán discovered the laws of this phenomenon which is called Vortex Street (see Figure 1). The frequency of this vortex shedding is proportional to the flow velocity within a certain range. By utilizing this effect, very precise flow and volume measurements can be taken, while including the surface flowing through.

Figure 1: Kármán Vortex Street

Configuration Vortex meters can be used for volume measurement of gases and liquids (e.g. type WZ 09). In the event of gases, they can be used in conjunction with additional instruments for pressure- and temperature-corrected volume measurement or in conjunction with a density meter for determining the mass flow. The vortex meter types WBZ 08 and WZ 07 can only be used for gases. A vortex meter has an electronic pulse output. Therefore, it can be used in processes with electronic computers, controllers and data-processing equipment.

DESCRIPTION

Typical Application-Specific Fluids

1 2 3 4 5 6 7 8 9 10 11 12

Acid gas Air Ammonia Argon Butadiene Butane Carbon dioxide Carbon monoxide Chlorine Ethane Ethylene Flare gas

13 14 15 16 17 18 19 20 21 22 23

Helium Hydrogen Methane Natural gas Neon Nitrogen Oxygen Pentane Propane Propylene Town gas

Method of Operation When a fluid flows around a body, vortices are shed periodically. In the wide range of Reynolds numbers, the number of vortices shed per unit of time is proportional to the rate of flow. Correct dimensioning of the measuring element and proper installation into the housing will therefore result in a fail-safe, high-precision measuring instrument for wide flow ranges (see Figure 2). The vortex frequency depends not only on the flow velocity, but also on the shape of the measuring element and the ratio between the size of the measuring element and the pipe diameter. The meter factor (pulses per unit of quantity) can be determined in advance by measuring the geometrical quantities. The meter factor is independent of pressure, temperature, density and viscosity. The vortices produced by the measuring element give rise to velocity and pressure oscillations. These pressure oscillations pass a thermistor sensor in the measuring channel. The thermistor sensor changes its resistance in the same rhythm. For custody transfer metering, the required signal monitoring is ensured by a double configuration.

DESCRIPTION

Construction Vortex meters consist of the following parts: case, measuring element, measuring head with thermistors and signal amplifiers. A vortex meter requires a metering line whose length is important for its accuracy and must be dimensioned in such a way that perturbing influences upstream and downstream of the vortex meter are avoided.

Additionally, a flow straightener is fitted into the inlet piping in order to prevent disturbances due to swirl and asymmetrical flow profiles. The meter case incorporates the measuring element sealed off by O-rings. Due to the fact that the thermistor sensors are fitted into the measuring channels of the measuring head, they are not directly exposed to the flow. This method of vortex sampling results in an optimum signal formation and allows inspection of thermistors to be carried out without interruption of operation. The downstream amplifier shapes and amplifies the signals outputted by the thermistors which are supplied by a constant current. This signal can be further processed and corrected by the RMG Flow Computers of the ERZ 2000 or EC 900 series or the CS 905 counter system.

Features Thanks to its simple construction, the absence of actuated parts, and its digital mode of operation, a vortex meter is a flow meter with a high reliability in operation and a high accuracy of measurement. Benefits:          

Wide measuring range (1/50) High accuracy (± 0.5%) Safe against overloading Installation at any meter position Indifferent to shocks or vibrations High reproducibility Double signal output Maintenance can be carried out without interruption of operation Better resistance to soiling than any other systems Explosion protection

DESCRIPTION

Instrumentation Due to its physical mode of operation, a vortex meter has no mechanical counter. A comprehensive range of additional electronic equipment is available for applications where vortex meters are used. E.g. 4

1. Pulse-processing devices 2. Electrical and electromechanical counters 3. Flow computers 4. Density correctors, volume correctors (ERZ 2000 / EC 900 Flow Computer

series), etc.

Output pulses can be directly transmitted to data-processing equipment and process control computers, etc.

Custody Transfer Metering A double-pulse transmitter is required for custody transfer metering. Moreover, a pulse-monitoring device must be installed in the computer. The RMG Flow Computers of the ERZ 2000 and EC 900 series are approved for custody transfer metering and are fitted with a double-pulse input and a monitoring device as standard. Definition

Reynolds number: Dimensionless number indicating the condition of the flow. Characteristic quantities of the Reynolds number include  Flow rate Qa  Pipe diameter DN  Density of the fluid   Dynamic viscosity of the fluid 

DESCRIPTION

Vortex Meter Type WBZ 08 DN 150 G650/1000/1600 Air 1 bar E [%]

Natural gas 40 bar

5 -1 10 4

10 5

ReDN

10 6

10 7

ReDN = 0.354

Qb DN



 

(ReDN  Qb  Pb)

Figure 2: Characteristic as a function of the Reynolds number

Pressure Loss: The pressure loss p of the metering line is calculated from the following equation: p  1900   

Q2 DN 4

Pressure loss p (mbar) Volume at actual conditions Q (m3/h) Nominal diameter DN (mm) Density at actual conditions  (kg/m3)

Field of Application – Table 1 Ranges of accuracy of measurement

Applications System WBZ 08,WZ 07 vortex meter WZ 09 vortex meter Orifice p transmitter Rotary displacement meter TRZ, TRZ-K turbine meter

Liquids

Gas

Liquefied gas

Measuring range

Linearity

Reproducibility in %

Accuracy in %

yes

50:1

± 0.31)

< ± 0.1

± 0.53)

yes

30:1

± 0.5

± 0.15

±1

yes

3:1

± 0.1

± 22)

yes

20:1

± 0.5

± 0.1

±1

yes

20:1

± 0.3

± 0.1

± 0.5

with DN = 40/50/80 ± 0.5% of the upper range value 3) accuracy < 0.5% for diameters larger than DN 100 1) 2)

DESCRIPTION

Nominal Diameter and Measuring Range DN mm / in

Size

Measuring range (custody transfer metering) (m³/h) Qnmin Qamin Qamax

Meter Max. factor K frequency** approx. f(Hz) (pulses/m³) (related to Qamax)

40 1 ½"

G G

40 65

3/ 6/ 13 5/ 10/ 20

65 100

16700

400

50 2"

G G

65 100

5/ 10/ 20 8/ 16/ 32

100 160

8000

365

80 3"

G G G

(100) 160 *250

8 13 8/ 20

160 250 400

2400

350

100 4"

G G G

(250) 400 *650

20 32 20/ 50

400 650 1000

1100

370

150 6"

G (650) G 1000 G *1600

130

50 80 50/ 130

1000 1600 2500

310

220

200 8"

G (1000) G 1600 G *2500

160

80 130 80/ 200

1600 2500 4000

140

260

250 10"

G (1600) G 2500 G *4000

200

130 200 130/ 320

2500 4000 6500

130

300 12"

G (2500) G 4000 G *6500

320

200 320 200/ 500

4000 6500 10000

110

400 16"

G (4000) G 6500 G *10000

320

320 500 320/ 800

6500 10000 16000

500 20"

G (6500) G 10000 G *16000

500

500 800 500/1300

10000 16000 25000

600 24"

G (10000) G 16000 G *25000

800

800 1300 800/2000

16000 25000 40000

DESCRIPTION

Due to physical laws, the lower range limit must be calculated when dimensioning the meter: Qa min 

Qn min  Pn Pa

[m3 / h]

However, the value for Qamin given in the above table cannot be violated downwards. The maximum measuring range 1:50 is only possible with sizes marked "*". Avoid any sizes which are indicated in parentheses. Pressure loss of the complete metering line: p  2000   a 

Qamin: Qnmin: Pa: f: K: Qa 

p: DN: a:

Qa 2 DN 4

Minimum quantity at actual conditions Minimum quantity at atmospheric pressure Minimum operating pressure (bara) Signal frequency (Hz) at Qamax Pulse value (meter factor) (pulses/m3) (guide value)

f  3600 K

[m3 / h]

Pressure loss (mbar) Nominal diameter (mm) Density at actual conditions (kg/m3)

DESCRIPTION

Dimensions Metering line for custody transfer metering applications with a density transducer and a condensate separator located in the outlet piping.

Sensors

Flow straightener

Flow meter Density transducer

Cover

Gas drier

Shut-off valves

Inlet piping

Insulating cover

DN Bluff body

Outlet piping

Vortex meter 1.5 DN

3 DN

2.5 DN 20 DN A

3 DN B

5 DN C

C**

L**

40 50 80

1 ½" 2" 3"

800 1000 1600

120 150 240

380 400 560

1300 1550 2400

1350

3190

100 150 200

4" 6" 8"

2000 3000 4000

300 450 600

600 750 1000

2900 4200 5600

1450 1200 1400

3750 4650 6000

250 10" 300 12" 400 16"

5000 6000 8000

750 900 1200

1250 1500 2000

7000 8400 11200

1550 1700 2000

7300 8600 11200

500 20" 600 24"

10000 12000

1500 1800

2500 3000

14000 16800

2500 3000

14000 16800

A B C L

= = = =

*) **)

Length of the inlet piping Length of the meter Length of the outlet piping Length of the metering line Standard length with two G ¾ or G ½ weldolets for PT 100 and one G ½ weldolet. With two pockets for the density transducer and the condensate separator and a maximum of eight weldolets. For DN 80 and 100, the outlet pipe is expanded to DN 150 in its middle part.

DESCRIPTION

WZ 07 Introduction The compact vortex meters for secondary metering of the WZ 07 series complement the tried-andtested WBZ 08 series. The vortex meters of the WZ 07 series have the same metering mechanism as the WBZ 08 design for custody transfer metering. Compact dimensions and very simple installation and control conditions result from integrating this metering mechanism into the metering line. Correction and further processing of volumeproportional output pulses can be carried out using the electronic standard accessories.

Special Features    

Metering mechanism of the vortex meter is integrated into the metering line. Length of the metering line: max. 14 x nominal diameter (see Table 2). Nominal diameters from DN 25 to DN 750. Accuracy < 1% of the measured value.

Fields of Application The compact WZ 07 vortex meters can be used in a variety of applications. They are characterized as follows:  Digital representation of measured values  High accuracy  Wide measuring range  Installation at any meter position  Safe against overloading  Easy to service  Single- or double-pulse measurement  Installation and removal of sensors without interruption of operation  Substitute for the conventional orifice metering technology

DESCRIPTION

Specifications Fluid: Measuring range: Accuracy:

Gas See Table 1 DN 25-150  1% of the measured value DN 200-750 with additional inlet piping Volume-proportional square-wave pulse, open collector 24 VDC PN 10 to PN 100 ANSI 150 to ANSI 600 standard - 10 to + 50°C - 40 to + 90°C special design Higher temperatures on request. Steel / high-quality steel / glass Approved for areas subject to explosion hazards Safety barrier: II (2) G [EEx ib] IIC Measuring sensor: II 2 G EEx ia IIC T4

Output: 10

Power supply: Pressure stages: Connecting flanges: Fluid temperature range: Material: Degree of protection:

Measuring Ranges – Table 2 (delta-shaped body)

1) 2)

Qamin 1) (m3/h)

25 40 50 80 100 150 200 250 300 400 500 600 750

1,5 2 4 10 15 30 80 130 200 320 500 800 1500

Qnmin 2) (m3/h) 10 15 20 30 40 65 80 130 200 320 500 800 1500

Qamax (m3/h)

Meter factor (pulses/m3)

30 100 200 600 1200 2500 5000 8000 12000 18000 30000 50000 80000

56000 15000 8000 2500 1100 320 140 70 40 20 10 5 2

Lower range limit Qamin Lower linear range limit depends on the pressure at measuring conditions pa

DESCRIPTION

Qa min 

Qnmin pa

, Qnmin (Table) at an atmospheric pressure of 1 bar

e.g. DN 40, lower linear range limit 1 bar: Qamin = 15 m3/h (Table) 3 bar: Qamin = 15/3 = 5 m3/h > 2 m3/h  30 bar: Qamin = 15/30 = 0.5 m3/h  < 2 m3/h

Qamin (Table) = 2 m3/h must not be violated downwards.

Pressure Loss: Metering line including flow straightener p  1800   

Qa 2 DN4

Pressure loss p (mbar) Volume at actual conditions Qa (m3/h) Nominal diameter DN (mm) Density at actual conditions  (kg/m3) Metering line without flow straightener (option) p  1250   

Qa 2 DN4

DESCRIPTION

General Drawing

Dimensions – Table 3 Nominal diameter

DN 25

275

350

DN 40

440

120

560

DN 50

550

150

700

DN 80

880

240

1120

DN 100

1100

300

1400

DN 150

1650

450

2100

DN 200

1400

600

2000

DN 250

1750

750

2500

DN 300

2100

900

3000

DN 400

2800

1200

4000

DN 500

4000

DN 600

4000

DN 750

4000

From DN 200 the bluff body is welded in. For this weld-in design, the dimensions are the same as for the flanged-end design. ............................................................................................................................................................................................................... Manual WBZ 08 · EN02 · 2011-05

DESCRIPTION

WZ 07-S Variant An especially compact variant is the WZ 07 without sensor pipework. Due to its construction, this vortex meter is particularly suitable for use with small nominal diameters or high pressures.

Arrangement of the bluff body and the measuring sensor on the WZ 07-S

Note to Installing the Sensor: If the meter is installed in horizontal position, turn the marking point until it reaches the 6 o'clock or 12 o'clock position. (Signal is the most pronounced.) After you have loosened the cap nut, if possible, turn the sensor only clock-wise until it reaches its optimum position.

Example of a WZ 07-S with high-pressure connections, two-channel design, Pr connection and a PT 100 integrated into the outlet section.

DESCRIPTION

Electronic System Overview



Safety barrier SBWS 02b

Amplifier WS 02b

Channel 1

Thermistors

Safety barrier SBWS 02b 

Amplifier WS 02b Channel 2

Channel 2

19" Subrack 24 VDC

Block diagram

First of all the signals of both thermistors pass the safety barrier which can be used for one or two measuring channels. This safety barrier separates the electric circuit in the area subject to explosion hazards from the downstream electronic system. Then both signals are amplified and filtered by two separate WS 02b amplifiers. Output signals (passive output) are square-wave pulses. The safety barrier and amplifiers are housed in a 19" subrack. The amplifiers are supplied with 24 VDC, whereas the safety barrier requires no voltage supply.

DESCRIPTION

Safety Barrier Method of Operation The safety barrier serves to connect two WBZ sensors with thermistors to two WS 02b amplifiers for vortex meters. The safety barrier sees to it that the circuit with the thermistors located in the area subject to explosion hazards remains intrinsically safe. There are two variants for sensors with thermistors of the Type THERMOMETRICS FP10DAxxxP-D available: Sensor installed in a standard case TF 01, TF 03: SBWS 02b/01-210/005/00 - for ambient temperatures up to 85°C Sensor installed in a special case TF 02 L: SBWS 02b/01-141/006/00 - for ambient temperatures up to 90°C - for aggressive gases

The safety barrier is a passive 2-channel Zener barrier which limits the electric energy supplied to the thermistors if a fault or error occurs. The two channels are brought together and earthed at the earth terminal (PE). However, the safety barrier is irrelevant to the measuring function of the WS 02b measuring amplifier, since the electrical operating conditions of the thermistor in undisturbed operation depend on the measuring amplifier. Specifications Type Safety Barrier Sensor type Sensor connections:

Explosion protection:

SBWS 02b/01-210/005/00

SBWS 02b/01-141/006/00

TF 01, TF 03 IOUT  8 mA. UOUT  14.1 V RI = 1.82 k

TF 02 L IOUT  6 mA. UOUT  14.1 V RI = 2.43 k

Ambient temperature:

II 2 G [EEx ib] IIC (PTB 02 ATEX 2200 X) -20°C  TA  60°C

Relative air humidity:

 95% without condensation

Outputs:

for connection of two measuring amplifiers for vortex meters (WS 02b)

Type of construction: Front plate: Connection options:

European standard-size card (160 mm * 100 mm) Height 3U-Depth 4U-2.5mm Al (32-pin) Connector as per DIN 41612 Style F

Type TF02 thermistors must only be used in conjunction with safety barrier of the type SBWS 02b/01-141/006/00! Otherwise explosion protection is not guaranteed.

DESCRIPTION

WS 02b Measuring Amplifier for Vortex Meters

Mode of Operation The WS 02b measuring amplifier for vortex meters (see the block diagram) supplies the thermistor with an adjustable constant current. This results in a DC voltage with a superimposed AC signal voltage being provided as measuring signal. The measuring signal is amplified in the input section. At the same time, the upstream and downstream bandpass filters reduce the frequencies outside the measuring frequency spectrum. Then the signal is directed to two filter channels which separate the characteristic frequency spectra of the measuring signal from each other. Depending on the available frequency, the measuring channel control system chooses the optimum channel for further processing the signal. The sinusoidal AC voltage available downstream of the intermediate repeater can already be converted under all operating conditions with a certainty of less than 10 per 10,000 pulses into square-wave pulses by a downstream Schmitt trigger. With this trigger method, a disturbing phase jitter may occur in the sequence of pulses. For this reason, the signal chain includes a controlled downstream jitter damping filter. The sequence of pulses at the output of this filter is impeccably triggered with a certainty of approx. 1 per 100,000. An optocoupler is used for potential-free decoupling of signals. The measuring amplifier for vortex meters meets the EMC requirements in accordance with the testing rules of the German Federal Institute of Physics and Metrology (PTB). Contrary to its predecessor WS 02a, a power pack was fitted onto the PCB of the WS 02b in order to dispense with a separate PCB for the power pack. Moreover, several elements for displaying status information and signals were added and the measuring amplifier for vortex meters was made to correspond to the most recent state of the art. Specifications Supply voltage: Power requirement:

18 to 27 VDC IIN  90 mA at UIN = 24 V

Isolation, primary / secondary:

VI  500 VDC 30 sec

Ambient temperature:

0°C  TA  50°C

Relative air humidity:

 95% without condensation

Measuring connection:

for connection of a WBZ sensor Type TF 01, TF 03 or TF 02 L; directly or via an SB WS 02b safety barrier IOUT  2.5 mA UOUT  24 V

Pulse output: Max. connected loads

Optocoupler output, passive (potential-free) UC  24 VDC + 10% IC  30 mA ICE  1 V at IC  2 mA

Voltage drop Type of construction:

European standard-size board (160 mm * 100 mm)

Front plate:

Height 3U-Depth 8U-2.5mm Al

Connection options:

Connectors as per DIN 41612 Style F

INSTALLATION

Installation Metering Line with Meter Vortex meters can be installed in any position. Only for the measurement of very humid gases must you install the meter in such a way that the bluff body is in vertical position and the thermistor terminals point to the top. If necessary, you must take special measures such as installing driers or filters. Additionally, a thermistor purging facility and a sensor heating are optionally available.

In order to avoid that the high accuracy of measurement of vortex meters is impaired by upstream or downstream fittings or valves, vortex meters of the Type WBZ 08 must be installed with the recommended inlet and outlet pipes (see page 8). The WZ 07 is already fitted with integrated inlet and outlet pipes. When assembling the metering line, you must observe instructions like those on the plate "Seal for inlet and outlet pipe". Moreover, you must make sure that the marked areas on the flanges abut on each other. Remove the yellow protective film at the flanges completely. Rests of this plastic film affect the flow profile and cause measuring errors! Static pressure should be measured at the p connection of the meter case. r

Electrical Connections and Wiring Mains connection of the amplifier of the vortex meter: 24 VDC. The safety barrier and the WS-02b electronic converter are completely wired and installed in a wallmounting case or a subrack. They must be located outside the area subject to explosion hazards. The thermistor sensors at the vortex meter are factory-wired with the terminals in the intrinsically safe (EEx i) connection box. Wiring of the EEx i connection box with the subrack and from there with the computer must be made on the spot in accordance with the wiring diagram (see page 18). For this purpose, you must use the following cable: LIYCY, 2x0.75 blue, twisted, max. length 150 m. The vortex meter can be fitted with an explosion-protected heating (230 VAC, 50 W) for heating the measuring head. This heating is factory-wired with the EEx e connection box.

INSTALLATION

Wiring Diagram for Amplifiers and the Safety Barrier L (+) N (-)

Flow Computer

PE 7

Connector J7

Channel 1

Output connector WA1

d18

z18

d18

z18

Amplifier WS 02b dz28

dz30

dz32

Amplifier WS 02b

dz2

dz4

dz2

dz4

d14

z14

dz28

dz30

dz32

+ 24V/DC PE

Safety barrier SBWS 02b d32

d20 d16 z16 z28

z20

Channel 1

Channel 2

19" Subrack

Area not subject to explosion hazards

Input connector W1

Cable LIYCY 2x0.75 blue, twisted max. length 150 m

Area subject to explosion hazards

+ 2



+ 3



Intrinsically safe (EEx i) connection box

Thermistors

STARTUP

Startup Required auxiliary equipment: 1 Oscilloscope 1 Ohmmeter

Checking the Resistance of the Thermistor Sensor

The sensors have a negative temperature coefficient. If the gas temperature rises, the sensor resistance declines. An intact thermistor sensor has the following resistance (R ) at a gas temperature of approx. 25°C: Standard design: approx. 8 k ± 30% (operating temperatures of -40°C to 80°C) High-temperature design: approx. 30 k ± 30% (operating temperatures of 0°C to 90°C)* 25

Prior to checking the resistance, you must absolutely switch off the voltage supply, since any connections or disconnections with voltage being applied may destroy the thermistors. For checking the resistance, you must disconnect the thermistor sensors to avoid wrong measurements being taken by the electronic system connected. Then take your measurement between the terminals 1 and 2 or 8 and 9 at the W1 connector or at the terminals 1 and 2 or 4 and 5 in the intrinsically safe (EEx i) connection box. When taking your measurement, you must comply with the relevant explosion-protection regulations, since the electric circuit must remain intrinsically safe even during measurement.

8 k ±30% at 25°C

Thermistor resistance [k]

30 k ±30% at 25°C

Temperature [°C] * only for dry gases without condensate! ............................................................................................................................................................................................................... Manual WBZ 08 · EN02 · 2011-05

STARTUP

Setting the Amplification Factor

Upon delivery of the device, the amplification factor is set to a standard value and must be optimized during startup. After replacing amplifier cards or thermistor sensors, you must set the amplification factor again. We would recommend you to set the amplification factor each time you start up the meter. You can set the amplification factor by means of the two rotary switches, located beneath the cover plate. RMG Messtechnik WBZ Verstärker WS 02b UB

Light-emitting diodes

Pegel > = <

Cover plate

Puls

Measuring sockets Rotary switches

V1 HP/TP EF GND V*10 V*01

The light-emitting diode for the operating voltage UB lights up if voltage is applied. You can read the frequency directly off the display of a Flow Computer of the Series ERZ 2000 or EC 900 connected. If there is no Flow Computer available, you must measure the signal frequency at the EF measuring socket of the amplifier. To set the amplification factor, first unscrew the cover plate. Then 4 measuring sockets (2 mm, for an oscilloscope with R  10 M) and 2 rotary switches will appear. Turning the rotary switch at the bottom will modify the amplification factor by little steps, whereas turning the rotary switch at the top will change the amplification factor by large steps (about 10 times as much). i

Example: WBZ 08 Diameter DN 80 Natural gas at 8 bar  Amplification factor 45 (see table on the next page) ............................................................................................................................................................................................................... Manual WBZ 08 · EN02 · 2011-05

STARTUP

There are several ways to set the amplification factor:

Rough setting Initial rough setting is to be made with the equipment being switched off, i.e. when there is no flow. If no order-related specifications are available, the amplification factor is set to 50 in the factory. For order-specific setting, the following values apply with a possible variation range of 卤10: Air

Natural gas or other gases

at 1.0129 bar and 20掳C

> 3 bar

for all operating pressures

40 - 80

100 - 250

> 250

Table: Standard values for rough setting

Fine setting Fine setting is to be made during operation, i.e. when there is flow. Attention:

Prior to fine setting, the heating must have been on for at least 1 hour during operation.

We would recommend making your setting with an average flow. However, the flow rate should be at least 10 to 20% higher than Qmin, so that the vortex frequency is higher than 10 to 30 Hz. The latter depends on the nominal size of the gas meter, so that a higher frequency is required for larger gas meters, for example. Setting the amplification factor by means of the light-emitting diodes Set the amplification factor in such a way that the "=" LED display lights up. If ">" lights up, the set amplification is too high and you must set a smaller amplification factor. If "<" lights up, you must increase amplification accordingly. In order to set an average value with constant flow at actual conditions, slowly increase amplification until ">" lights up. Make a note of this value. Then decrease amplification until "<" lights up. Determine the mean of these two values which will be the amplification factor to be set.

STARTUP

Setting the amplification factor using an oscilloscope For this purpose, you must pick off the signals downstream of the high-/low-pass filter (HP/TP socket, top right) and downstream of the end filter (EF socket, bottom left). All signals must show a neat sinusoidal course (see page 23).

At the EF socket, there must occur a sinusoidal signal with an amplitude of 5 to 10 Vss (see page 23, oscillogram C). If the signal is too small (less than 1 Vss), it is no longer converted into squarewave output signals. If amplitudes are too great (greater than 15 Vss), the amplifier is overloaded and may become unstable. This may result in additional pulses being produced. The quality of the thermistor signal can be detected by means of the V1 measuring socket (top left). However, this sinusoidal signal must clearly show zero passages, so that the downstream filtration can operate properly. (In this case, the low-frequency disturbance curve is to be regarded as zero line. See oscillogram B.)

Square-Wave Output Signal There are square-wave output signals (Channel 1 / Channel 2) available for further processing. The amplitude of the square-wave signal depends on downstream equipment. Note: Signals at this output can only be picked off, if the open collector is supplied externally, i.e. by the signal processor (< 10 V and < 10 mA). Output pulses can be visually monitored by means of the "Puls" diode.

Replacement of components As part of a repair it may be necessary to replace one or more of the following components:  Thermistor sensor  Amplifier WS 02b  Safety barrier SBWS 02b After replacement of the components listed above, no calibration is needed on a test rig. The date of the next recalibration also does not change.

STARTUP

Oscillograms

This illustration shows oscillograms of ideal signals under perfect flow conditions. The amplitude of the square-wave signal depends on downstream equipment. Signal A Signal of the preamplifier ............................. B Signal downstream of the prefilter ............... C Signal downstream of the end filter ............. D Output signal ...............................................

Pick-up V1  HP/TP  on the front of the WS 02b  EF Terminals 1 and 2 or 8 and 9 of the WA1 output connector

MAINTENANCE

Maintenance Thermistor Sensor Types TF 01 and TF 02

Fields of application for sensors (in hazardous areas of Zone 1) Pressure and ambient temperature: Type TF 01, TF 03: up to 100 bar, 85掳C (dimensions of TF 03 like TF 01) Type TF 02 L: up to 320 bar, 90掳C for aggressive fluids. ............................................................................................................................................................................................................... Manual WBZ 08 路 EN02 路 2011-05

MAINTENANCE

Inspection of the Thermistor Sensors Thermistor sensors may become soiled after a lengthy period of operation (the degree of soiling depends on the cleanness of the gas). In such a case, the computers of the ERZ 2000 and EC 900 series indicate a fault and start to operate in alarm mode. As an option, thermistor purging with filters is available. For inspection, cleaning or replacement purposes, the thermistor sensors can be removed as follows during operation: 1. 2. 3. 4. 5.

Open the cover. Shut the straight-way valve. Turn the handle of the vent valve by 180掳. (Arrow will point to the blank joint.) Open the blank joint at the vent valve by 1 turn and vent. Unscrew the cap nut towards the thermistor sensor support and pull out the tight sensor.

To clean the sensor, blow out the cross hole on the sensor case (see page 24) with compressed air. Reinstall the thermistor sensor in reverse order. Note: The marking point on the sensor case must point in the axial direction of the supply line (see page 24).

Inspection of the Bluff Body The bluff body must only be inspected if it is used with heavily soiled gases (landfill gas) or if you assume that it might have been damaged mechanically. To remove the bluff body, unscrew the fastening screw on the sensor side and remove the retaining plate. Then slide the bluff body towards the opposite side out of its seat. Before reinstalling the bluff body, you must check the O-rings. A pin inside the meter case ensures that the bluff body is exactly aligned with the direction of flow.

ANNEX

Annex Connector Pin Assignments of the SBWS 02b Safety Barrier Connector Pin Assignments of the WS 02b Measuring Amplifier for Vortex Meters 26

Parts List for the WBZ 08 / WZ 07 Vortex Meters Working Sheet A1: Error Curve as a Function of the Reynolds Number Re

Working Sheet A2: Characteristics of Industrial Gases Working Sheet A3: Influence of Pulsation on Vortex Meters Data Sheet for Vortex Meters Certificates of Conformity of the German Federal Institute of Physics and Metrology (PTB)

ANNEX

Connector Pin Assignments of the SBWS 02b Safety Barrier Pin

Signification

d2 z2 d4 z4 d6/z6 d8/z8 d10/z10 d12/z12 d14 z14 d16 z16 d18 z18 d20 z20 d22/z22 d24/z24 d26/z26 d28 z28 d30 z30 d32 z32

Output towards WS 02b, Channel 1, + n.c. n.c. Output towards WS 02b, Channel 2, + n.c. n.c. n.c. n.c. Output towards WS 02b, Channel 1, Output towards WS 02b, Channel 2, PE contacts, leading PE contacts, leading PE contacts, leading PE contacts, leading Sensor connection Thermistor 1, Sensor connection Thermistor 2, n.c. n.c. n.c. n.c. Sensor connection Thermistor 2, + n.c. n.c. Sensor connection Thermistor 1, + n.c.

Signification

d2/z2 d4/z4 d18 z18 d26 z26 d28 z28 d30 z30 d32 z32

Thermistor connection + Thermistor connection Optocoupler output pulse, + (collector) Optocoupler output pulse; - (emitter) PE terminal connection PE terminal connection Supply voltage +24V Supply voltage +24V Earth 0 V Earth 0 V PE terminal connection PE terminal connection

Connector Pin Assignments of the WS 02b Measuring Amplifier for Vortex Meters

ANNEX

Parts List for the WBZ 08 / WZ 07 Vortex Meters

ANNEX

Item Pcs. No.

Designation

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Case Bluff body O-ring Thermistor sensor Sensor case Ball valve with with venting plug Ball valve (green knob) Measuring head heating (option) Plastic cover Distribution box Flow straightener Inlet piping Outlet piping R ¾" Weldolet Seal as per DIN 2691 Screw boIt as per DIN 2510 Nut as per DIN 2510

1 1 2 1/2 1/2 2/4 2/4 1 1 1 1 1 1 1 2

* Case: GS-C25  Flanges as per DIN in St 37-2 or C22, ANSI in C 21 x Pipe: St 35.8-1 or III, RR StE 290. 7 or 360.7

Article No.

Material *x X10CrNiTi 189 Buna N (Viton)

00.47.395.00 16.80.000.14 84.07.077.00 84.07.076.00

86.90.33.00

50.34.104.00

PVC Al X5CrNi 189 x x St 35.8-I Jt 200 CK 35 C 35

 depending on: PN, DN, T  Special design:  X10CrNiMoTi 18 10

When placing your order, please specify: Type, DN, PN and manufacturer's number.

ANNEX

Working Sheet A1 Error Curve as a Function of the Reynolds Number ReD Example of an error curve

5 4

3 2 1 0 -1 -2 -3 5

10 4 X

10 5

ReD

100

10 6 5

1000

10 7 2

10000

108 2

0.01 2

0.1 2

1.0 2

10 0.01

0.1

100

ANNEX

Example: x)

X

Q D

Flow rate (at actual cond.) Q = 4800 m3/h Nominal dia.: DN = 250 Operating pressure: Natural gas p = 40 bar Density at actual conditions: ρ = 34 kg/m3 Dynamic viscosity:  = 10  10-5 x)

Reynolds number: ReD = 0.354  X

Q   D 

4800  19.2 250

ReD = 2.3  107   3.4  10 6 

31 F = -0.3%

Characteristic fluid values see Working Sheet A2

ANNEX

Working Sheet A2 Characteristics of Industrial Gases n Ri Standard Specific density gas constant

kg/mol

kg/m3 1.1715 1.2930 0.7718 1.7840

319.32 287.07 488.21 208.13

0.9916 0.9994 0.9844 0.9990

1.23 1.40 1.31 1.65

10 18 9 21

8.5 14 11.7 11.8

Gas

0106 106 Dynamic Kineviscosity matic viscosity

Mr Molar mass

Zn Supercompressibility factor at normal conditions

 Ratio of specific thermal capacity at 20°C

Pas.

J(kgK)

m2/s

Acetylene Air (dry) Ammonia Argon

C 2H 2 NH3 Ar C4H10

26.038 28.963 17.031 39.948

n-Butane i-Butane

C4H10 C 4H 8

58.123 58.123

2.708 2.697

143.05 143.05

0.9575 0.9615

1.66 ----

7 7

2.6 2.6

1-Butene 1,3-Butadiene

C 4H 6 Cl2

56.107 54.091

2.599 2.497

148.19 153.71

0.9631 0.9665

-------

7 --

2.8 ---

Carbon dioxide Carbon monoxide Carbon oxysulphide

HCI C 2H 6 C 2H 4

44.010 28.010 60.07

1.9880 1.2505 2.721

188.92 296.83 138.41

0.9932 0.9994 0.9849

1.30 1.40 ----

14 17 14

7 13.6 5

Chlorine

70.906

3.210

117.26

0.9855

1.35

3.8

Ethane Ethylene

CO CO2

30.069 28.054

1.3550 1.2611

276.51 296.37

0.9901 0.9925

1.19 1.24

9 9

6.6 7

Helium

COS

4.0026

0.17848

2077.2

1.0005

1.63

107

Hydrogen Hydrogen chloride Hydrogen sulphide

Kr -CH4

2.0158 36.461 34.076

0.08988 1.6422 1.5355

4124.6 228.04 244.00

1.00006 0.9906 0.9901

1.41 1.39 1.31

8 13 12

90 8 7.8

Krypton

CH3CI

83.80

3.749

99.22

0.9972

1.69

---

Methane Methyl chloride

Ne C 3H 8

16.043 50.491

0.7175 2.3074

518.25 164.67

0.9976 0.9763

1.31 ----

10 10

14 4.3

Neon

C 3H 6

20.179

0.8999

412.055

1.00048

1.64

Nitrogen Nitrogen monoxide Nitrous oxide

O2 SO2 H 2S

28.013 30.006 44.019

1.2504 1.3402 1.9780

296.80 277.09 188.91

0.9995 0.9990 0.9927

1.40 1.39 1.28

17 18 14

13.5 13.4 7.1

Oxygen

31.999

1.4290

259.83

0.9990

1.40

Propane Propylene

N 2O N2

44.096 42.080

2.0109 1.9129

188.55 197.58

0.9783 0.9815

1.13 ----

8 8

4 4.2

Sulphur dioxide

H 2O

64.059

2.9310

129.79

0.9751

1.27

3.8

Water vapour

18.015

0.8038

461.52

1.0000

1.33

16.2

18.64 19.02

0.84 0.85

446.0 437.0

0.9900 0.9980

1.31 1.29

11 10

13.1 11.8

Natural gas L group H group

ANNEX

Working Sheet A3 Influence of Pulsation on Vortex Meters Fundamentals A gas metering system can be affected by flow pulsations if the following equipment is installed upstream or downstream in the metering system:    

piston compressors rotary displacement meters gas pressure controllers lacking steadiness of operation piping where no gas flows (siphons).

Volume flow pulsation is the decisive quantity for assessing the performance of gas meters affected by pulsations. Volume flow pulsation is physically always linked with pressure variations. 2

  p  DN  K The following relation is established in a first approximation: Q rel rel Q

With this relation, it is possible to estimate volume flow pulsation on the basis of pressure pulsation, which can be measured in an easier way. However, direct measurement of volume flow pulsation should be preferred, since the results are more reliable. The crucial factor is the pulsation in the place of measurement. If pulsations are sufficiently high, the frequency of vortices at the vortex meter can be coupled to the frequency of pulsations due to flow-related effects. This is the case with certain pulsation frequencies. Then vortices are shed at the whole pulsation frequency or half the pulsation frequency. Disturbances in vortex shedding resulting from the coupling are generally reliably detected by a 2channel pulse monitoring system. Therefore, it is unlikely that measurement errors will not be detected. Due to the principle of the vortex meter, no inertia-related measurement errors can occur.

ANNEX

Limiting Values Frequency ranges - It is generally unlikely that measured values will be distorted in the frequency range beyond 100 Hz. In practice it is hardly possible to initiate any considerable flow variations at such frequencies. 34

- Disturbances are to be expected most frequently in the range between 0.1 Hz and 100 Hz, since with typical system dimensions an excitation of resonances of the gas column must be expected. Flow variations with a high relative amplitude may occur. - In the range below 0.1 Hz there is a quasi-steady flow which will not cause any distortion with the gas meters.

Pulsation amplitudes Investigations have shown that no disturbances are to be expected with relative flow pulsations of less than 5% (peak-to-peak) and relative pressure pulsations of less than 0.1% to 0.5% (peak-topeak). These data are to be regarded as approximate values depending on the flow rate and pulsation frequency involved.

ANNEX

Data Sheet Vortex Meter 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Mounting location Make Manufact.No. DN PN Length Max. pressure Meter size Qmin Meter factor KV Approval No. Inlet piping with flow straightener Outlet piping

Type Year Material Flanges Qmín (HP) Qmax

Hazardous area RMG

WBZ 08

35 G

7.222-80.02 Flanges Length Drawing No. Flanges Length Components Drawing No.

SBWS 02b Safety Barrier 16 17 18

Mounting location Make Degree of protection

Type

Outside hazardous area RMG SBWS 02b II 2 G [EEx ib] IIC

WBZ Vortex Signal Amplifier 19 20 21 22

Mounting location Make Voltage supply Measuring circuit

Type

Outside hazardous area RMG WS-02b, 1 channel 18 to 27 VDC U = max. 24 V, I = max. 30 mA

Explosion-Protected Heater for Sensor Heating 23 24

Mounting location Make, Type

25 26

Mains voltage Connecting cable

27 28 29

Explosion protection Degree of protection Temperature controller, surface temperature Dimensions H x W x D Material

Heat output

WBZ 08 cover Intertec, KH50 ExR Steel, heating pl. 8442 230 V/50 Hz 50 W 2 3x0.75 mm2 3x1.5 mm SIH 4GMH4G-J II 2 G EEx ia llC T4 EEx d llC T4 IP67 IP65 built-in <+70°C built-in <+135°C 125 x 120 x 64 140 x 60 x 30 Anodized aluminium, black