Liquid level instruments BM 24 /BM 51

Transcription

1 KROHNE 09/ GR/PRINTO Liquid level instruments / Status: 10/99 Variable area flowmeters Vortex flowmeters Flow controllers Electromagnetic flowmeters Ultrasonic flowmeters Mass flowmeters Level measuring instruments Communications engineering Engineering systems & solutions

2 Liquid level instruments / Level gauges are used for measuring liquid levels in open-topped or pressurized vessels and tanks. Operating principle Both instruments operate on the float principle. A float with built-in magnet system is guided on a non-magnetic tube. It follows the liquid level in the vessel, thereby causing the magnet system to move the follower magnet inside the tube. Changes in level are transmitted via a flexible wire cable to a measuring drum. The weight of the follower magnet is balanced by a spring motor. System operation is thus non-interacting. The indicating device and data transfer system are actuated by the measuring drum via a toothed gearing. Approved as part of an overfill protection system Legible local display, data transfer optional Various materials for aggressive media Up to 6 m tube length Temperature range C ( F) up to 40 bar (580 psig) Up to 24 m (80 ft) tube length 118

3 Special versions Guide tube extension Type designation: V If required, the guide tube can be extended between the two flanges (dimension a) in order to protect the indicator against overheating when product temperatures are high. Liquid/liquid interface detection Type designation: TS If two liquids with different densities are stored in one tank, then the float for detecting the boundary layer is designed such that it sinks in the light and floats on the heavy liquid. The difference in the densities of the two liquids needs to be at least 100 g/l (6.24 lb/ft 3 ). Below-tank-height indicator housing Type designation: U For large tanks, the indicator can be mounted as shown in order to permit better reading. In this case, the wire cable which transmits the level to the indicator is carried on guide rollers. Floating roof version Type designation: S The below-tank-height indicator mounting instrument is used for liquid level measurement in tanks with a floating roof. However, a guide tube with float is not provided; instead, the measuring cable is connected direct to the floating roof. Guide tube centering unit Tube centering is mandatory for approved instruments with guide tube lengths exceeding > 3 m (> 9.8 ft). The centering unit is standard equipment and is used if the level is to be measured almost down to the bottom of the tank. The float can slide over the end of the guide tube on the centering unit down to the bottom of the tank. The float immersion depth plus 37 mm (1.5 ) (end stop spring) is then the minimum level that can be measured. Dimensions in mm Flange connections of guide rollers for: Below-tank-height indicator housing, Floating roof version. Flanges to DIN 2501 and ANSI B 16.5 Flange 1 DN 40, PN 16 DN 25, PN /2, 150 lb 1, 150 lb Flange 2 DN 15, PN 16 DN 15, PN 16 1/2, 150 lb 1/2, 150 lb Product Overview Vibration Continuous, non-contact Switches Ultrasonic Radar Ultrasonic Buoyancy Capacitance Continuous, contact Ultrasonic Buoyancy TDR / 119

4 Responsibility for suitability and intended use of our instruments rests solely with the purchaser. Technical data Instrument type Measuring range Standard Option Tank product Density Standard For approved instruments* Viscosity Standard For approved instruments* Solids content* Particle size* Accuracy Max. allowable operating pressure Standard (51)/Ex/Z0 (51)F... dependent on flange pressure rating and float pressure resistance Indicator Scale markings 2-pointer version (standard) 1-pointer version 2-pointer version* Connection... flanges to DIN 2501 Standard Option... flanges to ANSI B for the heating device: pipe Information on higher pressure ratings and other standards on request Cable entry (for electrical options) Protection category (EN / IEC 529) Materials Housing Flange gasket Finish Flanges and guide tube Max. process temperature Without options ESK, K, P (51) with approval as part of an overfill protection system With Options ESK, K, P 3, 6, 9, 12 m (10, 20, 30, 40 ft) 18, 24 m (60, 80 ft) liquids kg/l ( lb/ft 3 ) kg/l ( lb/ft 3 ) 5000 mpa s 100 mpa s 100 g/l (6.24 lb/ft 3 ) dia. 200 µm ± 2 mm (± 0.08 ) of measured value 40 bar (580 psig) 26 bar (378 psig) 3 bar ( 44 psig) circular scale dia. 280 mm (11 ) m and cm m 3, %, ft or inches m 3, %, ft or inches and cm DN 50, PN 40 DN , PN , lb 10 x 1 mm (0.39 x 0.04 ) (only for standard version) PG 16 other connections on request IP 56, equivalent to NEMA 3 cast aluminium C 4400 electrostatic powder coating (RAL 5015) see table Instrument versions C ( F) C ( F) see Product temperatures for built-in options 1.5, 3, 6 m (5, 10, 20 ft) liquids kg/l ( lb/ft 3 ) kg/l ( lb/ft 3 ) 5000 mpa s 100 mpa s 100 g/l (6.24 lb/ft 3 ) dia. 200 µm ± 3 mm (± 0.12 ) of measured value 6 bar (87 psig) 5 bar (72 psig) 3 bar (44 psig) circular scale dia. 160 mm (6.3 ) m and cm m 3, %, ft or inches m 3, %, ft or inches and cm DN 80, PN 16 DN 50, DN 100 DN 200 / PN , lb M 18 x 1.5 mm other connections on request IP 56, equivalent to NEMA 3 grey cast iron buna N electrostatic powder coating (RAL 5015) C ( F) C ( F) * Only for instruments approved as part of an overfill protection system. 120 /

5 Selection of float type Select float as a function of the pressure, temperature and density of the liquid. In addition, the required degree of corrosion resistance must be considered when selecting materials. Form Dimensions Material Min. density Max. allowable Product temperature (diameter x wall thickness or height) operating pressure min. max. in mm in inches kg/l lb/ft 3 bar psig C F C F Ball 297 x x 0.06 Stainless steel (316 Ti) Ball 297 x x 0.08 Stainless steel (316 Ti) Ball 297 x x 0.10 Stainless steel (316 Ti) Cylinder 210 x x 9.84 PP Cylinder 170 x x 9.06 Hard glass Cylinder 166 x x 8.27 PVDF Cylinder 185 x x 8.27 PTFE bonded with PFA Cylinder 210 x x 9.84 PVC Ball 297 x x 0.08 Hastelloy-C Ball 255 x x 0.08 Titanium Disk 195 x x 7.28 Stainless steel (316 Ti) Cylinder 142 x x 6.50 Titanium Cylinder 140 x x 7.87 Hard glass Cylinder 190 x x 7.09 PP Cylinder 140 x x 8.31 PVC Instruments approved for use in Zone 0 (EC) Ball 297 x x 0.06 Stainless steel (316 Ti) Ball 297 x x 0.08 Stainless steel (316 Ti) Ball 297 x x 0.08 Hastelloy-C Ball 255 x x 0.08 Titanium Disk 195 x x 7.28 Stainless steel (316 Ti) Cylinder 142 x x 6.50 Titanium Instruments approved as part of an overfill protection system Ball 297 x x 0.06 Stainless steel (316 Ti) Ball 297 x x 0.08 Stainless steel (316 Ti) Ball 297 x x 0.08 Hastelloy-C Ball 255 x x 0.08 Titanium Cylinder 142 x x 6.50 Titanium Disk 195 x x 7.28 Stainless steel (316 Ti) Cylinder 142 x x 6.50 Titanium Important: The specified max. allowable operating pressure applies to 20 C (68 F) only! Float test pressure = 1.3 times the max. allowable operating pressure. (Approved instruments = 1.5 times the max. allowable operating pressure.) Product Overview Vibration Continuous, non-contact Switches Ultrasonic Radar Ultrasonic Buoyancy Capacitance Product temperatures for built-in options ESK/K, P/K C F C F Hazardous areas, ambient temperature < 60 C (140 F) Non-hazardous areas, ambient temperature < 40 C (104 F) Non-hazardous areas, ambient temperature < 60 C (140 F) P Hazardous areas, ambient temperature < 60 C (140 F) Non-hazardous areas, ambient temperature < 40 C (104 F) Non-hazardous areas, ambient temperature < 60 C (140 F) Options ESK, K, P: see Indication and long-distance data transmission Continuous, contact Ultrasonic Buoyancy TDR / 121

6 Instrument versions Version Flange material Guide tube material Tube diameters < 10 m < 32.8 ft > 10 m > 32.8 ft mm inches mm inches /N Steel = C22 (AISI C 1020) Stainless steel (316 Ti) 44.5 x x x x 0.14 ( DN 200, 8 ) 48.3 x x 0.14 /NR** Steel = C22 (AISI C 1020) Stainless steel (316 Ti) 44.5 x x x x 0.14 (DN 300, 12 ) 48.3 x x 0.14 Stainless steel (316 Ti) plated /RR Stainless steel (316 Ti) Stainless steel (316 Ti) 44.5 x x x x x x 0.14 /R-PP Stainless steel (316 Ti) Stainless steel (316 Ti) 44.5 x x 0.01 RF coated with PP with PP tube 50 x x 0.01 /R-PVC Stainless steel (316 Ti) Stainless steel (316 Ti) 44.5 x x 0.01 RF coated with PVC with PVC tube 50 x x 0.01 /R-PTFE Stainless steel (316 Ti) Stainless steel (316 Ti) 44.5 x x x x 0.14 RF coated with PTFE with PTFE tube 50 x x x x 0.12 /R-AL Stainless steel (316 Ti) Stainless steel (316 Ti) 44.5 x x x x 0.14 (AISI C 1020) with aluminium tube 50 x x x x 0.12 aluminium plated / B* Version same as /N, Stainless steel (316 Ti) 28 x x /NR, /RR double-walled for heating /RR Stainless steel (316Ti) Stainless steel (316 Ti) 28 x x /R-PTFE Steel = C22 Stainless steel (304) 28 x x (AISI C 1020) with PTFE tube RF coated with PTFE /R-PP Steel = C22 Stainless steel (304) 28 x x (AISI C 1020) with PP tube RF coated with PP /M Steel = C22 Stainless steel (304) 28 x x (marine) (AISI C 1020) ** only with mounting flange > DN 80 (ANSI 3 ) ** only with mounting flange > DN 100 (ANSI 4 ) 122 /

7 Indication and long-distance data transmission Limit switches Up to four electronic limit switches, Type TG 22 or SC 3,5-N0, may be installed in the indicators to allow initiation of signalling or switching functions at specific levels. These limit switches utilize an inductive slot sensor actuated by an aluminium vane that is mounted in the indicator mechanism. Once a preset level has been reached, the aluminium vane dips into the sensor slot and dampens its oscillating circuit, thus initiating the appropriate signalling or switching functions. An isolation switching amplifier is required to operate the TG 22 or SC 3,5-N0. If limit switches are provided, the instrument type designation is extended by the symbols K1 K4 (e.g. /NR/K4-...). Electrical signal output To convert the measured value into a current of 4 to 20 ma, the ESK transmitter is built into the indicator housing. The ESK is suitable for installation in hazardous areas. For ordering, the type designation of the electrical signal output is extended by the letters ESK (e.g. /RR/ESK-...). Suitable thermal protection can be fitted for high process temperatures. Pneumatic signal output A WT 80 pneumatic converter with VR 80 amplifier may be built into the indicator housing of the and to allow long-distance data transmission. To order, the type designation of the instrument with a pneumatic signal output is extended by the code letter P (e.g. /RR/P-...). Available versions K ESK P K1 K4 + ESK K1 K4 + P (K1, K2 + ESK) Product Overview Continuous, non-contact Switches Ultrasonic Radar Ultrasonic Buoyancy Capacitance Continuous, contact Ultrasonic Buoyancy TDR Vibration / 123

8 Technical data Limit switches TG 22 / SC 3.5-N0 Rated voltage 8 V DC Power consumption active area clear 3 ma active area obscured 1 ma Ambient temperature C ( F) Protection category to EN 60529/IEC 529 IP 67, equivalent to NEMA 6 Electromagnetic compatibility (EMC) (SC 3,5-N0) to EN , EN Electrical characteristics to DIN (NAMUR) Only relevant for use in hazardous areas! Only for connection to intrinsically safe circuits with the following peak values: TG 22 SC 3.5-N0 No-load voltage U O 15.5 V 16 V Short-circuit voltage I K 52 ma 52 ma Output P 169 mw 169 mw Self-inductance (Li) 160 µh 150 µh Self-capacitance (Ci) 40 nf 100 nf Connection diagram TG 22 / SC 3,5-N0 K1 = 1 Limit switch, Terminals 1,2 K2 = 2 Limit switches, Terminals 3,4 K3 = 3 Limit switches, Terminals 5,6 K4 = 4 Limit switches, Terminals 7,8 Individual type approval TG 22 Individual type approval SC 3.5-N0 PTB No. Ex-83/2022 X PTB No. Ex-95.D.2195X Electrical signal output ESK Power supply Current consumption Repeatability < 0.1%* Power influence < 0.1%* Load resistance dependence < 0.1%* Max. load resistance/load 2-wire circuit V DC 4 20 ma for 0% 110% of measured value RA = U 12.7 V, max. 800 Ω 20 ma Temperature influence < 10 µa/k of measured value* Ambient temperature at ESK C ( F) Linearity error < ± 0.1%* Protection category to EN 60529/IEC 529 IP 20, equivalent to NEMA 1 *without considering the resolution steps Only relevant for use in hazardous areas! Only for connection to intrinsically safe circuits with the following peak values: ESK No-load voltage U O Short-circuit current I K Output P Effective inner self-capacitance (Ci) Effective inner self-inductance (Li) Individual type approval 30 V 100 ma 1 W < 20 nf negligible PTB No. Ex-94.C.2067 ESK R ext. = 800 Ω 4 20 ma U s = V DC Pneumatic converter WT 80 Inlet air pressure 1.4 bar ± 0.1 bar (20.3 psig ± 1.45 psig) Air consumption (normal) 480 l/h (2.1 SCFM) Max. air capacity 1800 l/h (7.9 SCFM) Output bar ( psig) Linearity error ± 0.5% Hysteresis 0.25% Sensitivity 0.1% Ambient temperature at WT C ( F) Temperature effect 0.03% / C (0.054% / F) Inlet pressure dependence 0.2% / 0.1 bar (0.14% / 1 psig) Load characteristic 1.2% at 300 l/h (1.3 SCFM) [at 0.6 bar (8.70 psig)] 3% at 600 l/h (2.6 SCFM) Connections 1 /8 NPT 124 /

9 Dimensions and weights of instruments with 1 m (3.28 ft) guide tube length and standard float. = 31 kg (4 kg)* [70 lb (9 lb)*] = 25 kg (2 kg)* [56 lb (4.5 lb)*] * for each additional 1 meter (3.28 ft) tube length Product Overview Vibration Continuous, non-contact Switches Ultrasonic Radar Ultrasonic Buoyancy Capacitance Dimensions in mm (inches) Continuous, contact Ultrasonic Buoyancy TDR / 125

10 Approvals Application Only with explosion protection In stationary storage tanks for flammable water pollutants, classes AI, AII and B (excl. CS 2 ), float and guide tube in Zone 0 Overfill protection with explosion protection In stationary storage tanks [max. operating pressure is 3 bar (43.5 psig)] for flammable water pollutants, classes AI, AII and B (excl. CS 2 ), float and guide tube in Zone 0 Instrument version /... /Z0 /... /P/Z0 /... /Kn/Ex/Z0 /... /ESK/Ex/Z0 /... /ESK/Kn/Ex/Z0 /... /Z0 /... /P/Z0 /... /ESK/Ex/Z0 /... /Kn/Ex/Z0 /... /P/Kn/Ex/Z0 /... /ESK/Kn/Ex/Z0 /... /Kn-F/Ex/Z0 /... /P-F/Z0 } } Certification mark PTB-No. lll B/S 1167 PTB-No. lll B/S 1932 PTB-No. Ex-83/2014 PTB-No. lll B/S 1017 PTB-No. lll B/S 1930 PTB-No. Ex-83/2015 PTB-No. Ex-83/2055 F PTB-No. lll B/S 1933 F Overfill protection without explosion protection In stationary storage tanks [max. operating pressure is 3 bar (43.5 psig)] for flammable water pollutants, class AlII /... /Kn-F/WB /... /P-F/WB PTB-No. lll B/S 1816 F PTB-No. lll B/S 1933 F Type code Instrument Liquid level instrument Liquid level instrument Material See table Instrument versions Contacts K n n = number of contacts (max. 4) Built-in options ESK Electrical signal output ESK P Pneumatic signal output Range of application N Normal range Z0 Mechanical instrument with float and guide tube in Zone 0; flammable, water pollutants liquids, classes AI, AII and B Ex/Z0 Electrical equipment for use in hazardous areas F/Ex/Z0 Hazardous-area electrical equipment as part of an overfill protection system for flammable water pollutants, classes A I, A II and B F/WB Part of an overfill protection system for flammable water pollutants, class A III Special versions* V Guide tube extension TS Liquid/liquid interface detection U Below-tank-height indicator housing S Floating roof version ** B Heating system ( only)** BM ** not for instruments approved as part of an overfill protection system ** not for instruments approved for use in Zone 0 (EC) 126 /