Visu

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EKA

Member of the Group

Certified accordingISO 9001:2000

Certified accordingPED 97/23/EC

Certified accordingATEX 94/9/EC

WEKA_Fly_VLI_07_EN.qxd 18.5.2007 9:31 Uhr Seite 7

Prin

cipl

es o

f des

ign ● Single-pole Magnet System

The WEKA VLI operating principle is basedon the use of a permanent bar magnetsystem which ensures the safe and reliableactivation of visual indication elements(flags), switches and transmitters, evenwhen used on thick-wall high-pressure indi-cator pipe.

● Magnetic Guide Tape

The patented magnetic guide tape is inte-grated within the indication rail to ensurethe float bar magnet is always aligned like acompass needle to the polarized flags andswitches. This ensures continuous reliabi-lity of the indicating, switching and trans-mitter control functions.

● Magnetic Coupling

Every flag of the WEKA indication rail isequipped with its own permanent magnet.Thus the indication flags magneticallyinterlock with each other and so are kept ina stable position. The patented guide tapefurther enhances performance through themagnetic damping effect that producessafe and reliable indication of liquid level,even under difficult applications with rapidlychanging liquid levels or vibrations.

● Temperature Stability

The magnetic materials used in the WEKASystem have been selected for optimal performance even at extreme tempera-tures. Years of experience have proven ourpreconditioning of components ensuringnegligible degradation of magnetic flux.

● Compact Design

The low weight of the WEKA bar magnetpermits the use of lightweight hermeticallysealed floats. Compact in size, the WEKAfloats ensure the highest possible diameterdifference between float OD and tube ID –an important advantage when dirty or highlyviscous liquids need to be measured. The short float design also often enables alarger indication range compared to compe-titive products.

● Multi-functional:

Three functions in one system!

– Level indicator– Level switch – Level transmitter

Magnetic

guide tape

Float

Indication flags

with integrated

permanent magnets

Bar magnet

Pipe

Diverse float types are available

for the different applications

WEKA VLIs can be mounted

in various ways

WEKA_Fly_VLI_07_EN.qxd 18.5.2007 9:31 Uhr Seite 8

Type

Execution

Max. operating pressure @ 20 °C

Operating temperature

Pipe size

Minimum density

Recommended viscosity of the fluidAll data are valid for the basic versions

34000E

A, K

up to 6 bar

–40 up to +100 °C

OD 33.7 mm

> 0.6 g/cm3

max. 150 cSt

Series Economy-Line

23614E

A, K

up to 6 bar

–40 up to +100 °C

OD 53 mm

> 0.8 g/cm3

max. 600 cSt

Economy-Line

The WEKA VLI (Visual Level Indicator) pro-gram is built up in a modular system. It cantherefore be readily configured to preciselymatch the requirements of a very wide variety of applications and operating condi-tions. Within each series the basic execu-

Upper and lower process ports: top to bottomUpper float chamber end: threaded capLower float chamber end:threaded flange

Execution-A

Upper and lower process ports: top to bottomUpper and lower float chamber ends: threaded flange

Execution -B

Upper and lower process ports: side to sideUpper float chamber end: capLower float chamber end: service flange

Execution -K

Upper and lower process ports: side to sideUpper and lower floatchamber ends: service flange

Execution -O

tions -A, -B, -K and -O are available: Upperand lower process connections can be topto bottom or side to side. But also mixedversions with a lateral and side processconnection can be ordered.

● Modular Design

VLI p

rogr

am

WEKA_Flyer_VLI_07_EN.qxd 30.5.2007 15:22 Uhr Seite 1

23614

A, B, K, O

up to 6 bar

–40 up to +150 °C

OD 53 mm

> 0.6 g/cm3 (> 0.4g/cm3)

max. 600 cSt

Standard 6

34300

A, B, K, O

up to 20 bar

–40 up to +400 °C

OD 53 mm

> 0.6 g/cm3 (> 0.4g/cm3)

max. 600 cSt

Standard 20

32755

A, B, K, O

up to 50 bar

–40 up to +400 °C

OD 54 mm

> 0.6 g/cm3 (> 0.4g/cm3)

max. 600 cSt

Standard 50

● Wide range of operating conditions

Operating pressures can be from vacuumto 500 bar. Float chambers are availablewith design pressures up to 630 bar. Liquiddensities > 0.3 g/cm3 and media tempera-tures from 77 K to 673 K (–196 °C to+400 °C) allow use for applications likecryogenic liquid gases LPG/LNG, waterhydraulics and steam boilers. Closed floatsare available for most liquids at pressuresup to 350 bar. Open floats are available fornon condensating liquids at pressures up to630 bar.

● Energy-free, reliable operation

WEKA VLIs are ideally suited for plant start-up operations. The indication function does not require electrical power. The floatprinciple makes this a direct method oflevel measurement, with definite level indi-cation. The control functions of a VLI areindependent of its display function. There-fore the level is always observable, even ifthe power supply fails.

Standard materials

– Stainless steel 316/316L1.4404 / 1.44321.4435

Group A4 austenitic steel

Stainless steel materials

as option

– 304/304L 1.4301 / 1.4306 1.4307

– (316Ti) 1.4571– 321 1.4541

Stainless steel with higher

molybdenum content, e.g.

– 1.4539 (904L; UNS N08904)– 254 SMO (UNS 31254)

Nickel alloys and special

metals, e.g

– Inconel®/Incoloy®/Hastelloy®

– Titanium alloys– Zirconium and Tantalum– Aluminum alloys

Engineered Plastics

– PVDF, PP, PE, PVC– ECTFE (Halar) coating– PTFE-PFA lining– Teflon-PFA coating

WEKA VLI Level Indicators can be manufactured accordingto special request in almost anynon-magnetic material, subject tophysical properties and chemicalcompatibility.

● Versatility through choice of materials

WEKA VLI Smart-Line,

Type 34000-K

Smart-Line 50

34000/34110

A, B, K, O

up to 50 bar

–40 up to +250 °C

OD 33.7 mm

> 0.6 g/cm3

max. 150 cSt

integrated shut-off valves

WEKA_Fly_VLI_07_EN.qxd 18.5.2007 9:29 Uhr Seite 2

Diverse

A, B, K, O

up to 500 bar

–10 up to +400 °C

diverse

> 0.6 g/cm3 (> 0.4g/cm3)

max. 600 cSt

High Pressure – Power

Diverse

A, B, K, O

up to 630 bar

–80 up to +400 °C

diverse

> 0.3 g/cm3

max. 600 cSt

Petro

Diverse

–

up to 50 bar

–40 up to +400 °C

diverse

> 0.4 g/cm3

max. 600 cSt

Top of Tank

Diverse

A, B, K, O

up to 10 bar

according to material

diverse

> 0.6 g/cm3

max. 600 cSt

Engineered Plastic

Petro-VLI – Our solution for your

petrochemical applications

● Excellent Readability

The wide colour contrasted indicating flagsare easily and clearly readable, even fromfar distances. The flag elements are nor-mally red and aluminum coloured, but canbe optionally ordered with alternative colourcombinations. Difficult liquids in corrosiveand high/low temperature applications donot effect the reliable functioning of WEKAVLIs, because the liquid inside the floatchamber is totally isolated from the indica-tion rail. For the same reason, readability isnot impaired by turbid conditions.

● Level Measurement à la carte

WEKA VLIs can provide an optimal solutionfor almost any level measuring and controlapplication. For most applications, a suit-able indicator can be configured from stan-dard modular components. Special solu-tions are frequently needed for unusualoperating and installation conditions. Ourcustomers can take advantage of our 40 year experience in manufacturing cus-tom level indicators based on the provenWEKA design of magnetic float and indica-tion rail. We cover an extremely wide rangeof special level instrumentation require-

ments. If necessary, the standard interfacescan be adapted to match the requirementsof customer’s control systems. Magneticflag elements of WEKA VLI indication railscan be supplied with colour combinationsother than the standard colours. The WEKAmagnet and indication rail system can alsobe used for position indication of hydraulicand pneumatic cylinder pistons and pres-sure accumulator diaphragms. WEKA’sextensive custom design expertise can pro-duce reliable instrumentation solutions for linear displacement monitoring require-ments.

● Applications

WEKA has accumulated a wealth of knowl-edge about design and manufacturing of indicators and sensors for special applica-tions. We have many years of practicalexperience in the use of WEKA VLI LevelIndicators in chemical and other processindustries, shipbuilding, thermal powerplants, hydraulic systems, railways, vehicu-lar applications, petrochemical industries,and refrigeration systems, to name just a few.

WEKA_Fly_VLI_07_EN.qxd 18.5.2007 9:29 Uhr Seite 3

Indication Rails

The indication rails of WEKA VLIs are neverin contact with the process media, and areconsequently maintenance-free. The flagsof these indication rails are 36 mm wide,and therefore easily read even from far distances. The lightweight flags are mag-netically coupled to each other and respondpositively even at float displacementspeeds of 2 meters per second. The specialdesign of WEKA VLIs ensures reliable read-out at all times: the flags hold their posi-tions even in the presence of vibration andtemperature variations. For outdoor installa-tions, refrigerant applications and food-pro-cessing industries we recommend indica-tion rails with a polyolefin protective tubewhich is more resistant towards aggressiveatmospheres, and also prevents ice forma-tion and condensation.– The standard indication rail is made ofpolycarbonate. This is suitable for mediatemperatures ranging from cryogenic to+150 °C, and has a viewing angle of 240°.The profile has stainless steel end-caps.The flags are red and aluminum anodized, but are optionally available with other colour combinations, for example to conform to a process media colour coding scheme. – For media temperatures up to +250 °C, the rail is made of alu-minum and the cover of trans-parent polycarbonate.– For media temperatures up to +400 °C,the rail is made of aluminum and the coverof glass. The flags are black and aluminiumenamel varnished.

Magnetic Switches

WEKA VLIs are available with magneticswitches installed at the rear of the floatchamber, actuated by the rear field of thebar magnet in the float. These switches add level detection functions to VLIs. Theswitches may be connected directly toinputs of PLCs or computer-based systems,or through contactors for control of valvesor pumps. The magnetic switches are bi-stable: each is latched in one state (open orclosed) on the first pass of the float’s barmagnet, and reset to the original state onthe second (reverse) pass. The magneticswitches are available as on-off (SPST) orchangeover (SPDT) types. The stainlesssteel housings allow them to be used inpractically any type of environment, andwith media temperatures up to +350 °C.

2

1 The number of switching points is limitedonly by the availability of space. Magneticswitch modules are available for use inhighly combustible atmospheres: either asintrinsically safe (EEx i) versions or withpressure-tight explosion-proof (EEx d) hous-ings that conform to the European Directive94/9/EC (ATEX).

Transmitters

WEKA VLIs are available with an optionalelectronic transmitter to provide a continu-ously variable electrical signal that can befed to a remote level indicator, PID con-troller, recorder or PLC. This can be in theform of a 3-wire (current or resistance) or 2-wire (current loop) output. These trans-mitters are available for media tempera-tures up to +350 °C. A choice of outputconnections are available: plug-in connector,terminal box, or pre-wired cable lead. Trans-mitters are optionally available for use inhighly combustible atmospheres: either asintrinsically safe (EEx i) versions or withpressure-tight explosion-proof (EEx d) hous-ings that conform to the European Directive94/9/EG (ATEX).

Measuring Scales

Measuring scales are available with printedor engraved aluminium dibond or stainlesssteel scales. The standard scale division is 10 cm: users may optionally order otherscale divisions.

Detailed information about the WEKA VLIproduct range, including accessories, isavailable at our website www.weka-ag.ch.

4

3

1

2

3

4

Transmitters make the visual indicator

to a level transmitter

WEKA VLI Standard, Type 34300-K

ON/OFF

ON/OFF

2

Magnetic

switches

are available

in various

versions

3

20 mA100%

4 mA0%

VLI C

ompo

nent

s

WEKA_Fly_VLI_07_EN.qxd 21.5.2007 14:44 Uhr Seite 4

1940 Arthur Welter and August Karrer founded WEKA GmbH

1949 reorganized as WEKA AG1950 WEKA Stainless Steel Valves1962 First patent for the WEKA Magnetic Level Indicator1978 WEKA Cryogenic Valves and Couplings 1979 License contract with GEMS Sensors, USA,

for WEKA Magnetic Level Indicators1981 WEKA becomes part of the IMO Group, USA1982 Approval according to the German (AD-HP 0)

and Swiss (SVDB501) pressure vessel rulesAudit of the first WEKA Quality Control System

1991 New facilities in Bäretswil, approx. 25 km south-east of Zurich

1995 Takeover of the European production of the GEMS Tank Level Indication Systems

1997 WEKA, as part of GEMS Sensors Group, is acquired by Danaher Corp., USA

2001 WEKA becomes member of the ARCA Group, Germany

2002 Audit of the Total Quality Management System (TQM) by German Lloyd according toISO 9001:2000 and CE directive 97/23/EC Modul H/H1

2003 Approval by Zelm Ex according CE directive 94/9/CE (ATEX 95)

●Kn

ow-H

ow●

Qual

ity●

Flex

ibili

ty

Member of the ARCA Flow Group:

www.arca-valve.com www.feluwa.com

www.artes-valve.com

www.von-rohr.ch

www.weka-ag.ch

WEKA_Fly_VLI_07_EN.qxd 18.5.2007 9:30 Uhr Seite 5

Flye

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Visual Level Indicators

Tank Level Indicators

Cryogenic Components

Stainless Steel Valves

WEKA AG, Schürlistrasse 8

CH-8344 Bäretswil, Switzerland

Phone +41 43 833 43 43

Fax +41 43 833 43 29

info@weka-ag.ch · www.weka-ag.ch

Your contact for WEKA Tank Level Indicators:

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WEKA_Fly_VLI_07_EN.qxd 18.5.2007 9:30 Uhr Seite 6