Differential Pressure and Flow Meter Media 5 Indicator 160 PN 40

Transcription

1 Differential Pressure and Flow Meter Media 5 Indicator 160 PN 40 Application Instrument designed to measure and indicate differential pressure or measured variables derived from it For gases or liquids Differential pressure ranges from mbar Static pressures up to 40 bar Optionally with limit switch with two inductive alarm contacts. Optional measurements: Liquid level in pressure tanks, especially for cryogenic, liquefied gases Differential pressure between flow and return pipe Pressure drop across valves and filters Flow rate acc. to the differential pressure method Special features Suitable for liquids, gases and steam Limit switch can be easily retrofitted Overloadable on one side up to the perm. static pressure Suitable for field (degree of protection IP 54) and panel mounting Zero adjustment on the front Adjustment of measuring span 1:2 Housing of indicating unit with burst protection Directly connectable valve block (flange mounting) with test connection to check the pressure in the tank Connection for pressure switch Fig. 1 Media 5, Indicator 160 with attached valve block and operating pressure gauge Versions (Figs. 1 and 2) Media 5 consisting of: Indicator NG 160 with pointer mechanism Differential pressure cell (brass) PN 40 1) Version free of oil and grease for oxygen Measuring ranges from mbar ECO measuring diaphragm Zero adjustment on the front Process medium connection G 3/8 A Optionally equippable with: Scales Scale from 100% linear or squared; Scale according to DIN 19204; Detachable scales for different media; Special scales Inductive limit switch with up to three alarm contacts A1/A2/A3 (proximity switches) Version for hazardous locations Valve block directly flange mounted onto Media 5 devices Pressure gauge Screw joints Special versions available on request 1 2 Fig. 2 Media 5, Indicator 160 with limit switches and attached valve block with operating pressure gauge 1 Zero adjustment 2 Alarm contacts A1/A2 3 Valve block with pressure gauge and shut-off valves 4 Screw joints 3 4 1) Nominal pressure PN 50 available on request Associated Information Sheet T 9500 EN Edition September 1999 Data Sheet T 9519 EN

2 Principle of operation (Fig. 3) The differential pressure cell operates according to the deflection method and contains a ECO measuring diaphragm (1.5) which is designed to handle measuring spans from mbar. The diaphragm rod (1.7) is connected to a lever (1.8) and is supported and guided by the measuring springs. The lever leads the deflection of the measuring system out of the pressure chamber. The pressure chamber is sealed by means of a flexible disk (1.9). The measuring springs, which are connected to the housing, and the diaphragm ensure that the position of the lever is independent of the static pressure. The differential pressure cell can be overloaded from one side, because the measuring diaphragm flexes against the housing wall whenever the measured values are out of range. The differential pressure p = p 1 p 2 produces a force on the diaphragm (1.5) which is balanced by the measuring springs (1.4). The deflection of the measuring diaphragm and the lever (1.8) is proportional to the differential pressure measured and is converted to pointer (2.4) position with the adjustable transmission element (2.1) and the pointer mechanism (2.2) having jewelled bearings. The measuring springs (1.4) installed in the differential pressure cell determine the lower and upper limit of the respective measuring span (measuring range limit) of the device (see Table 2 "Technical data"). The span can be continuously adjusted within these limits of application according to the ratio 1:2 at the transmission element. This adjustment changes the transmission ratio between the lever (1.8) and the pointer mechanism (2.2). The measuring unit shaft (3.1) carries the metal tags (3.2) and moves them according to the operating direction into the limit switch unit with the two alarm contacts (proximity switches) A1 and A2 (3.3). If a metal tag enters the inductive field of the associated proximity switch, the switch becomes highly resistive (contact open). If the tag leaves the inductive field, the proximity switch becomes low resistive (contact closed). This function corresponds to that of a mechanical-type switching contact. The proximity switches are adjustable independent of one another and according to any user requirement. They provide a signal when the differential pressure either increases or decreases and the metal tags enter or leave the inductive field of the switch. The proximity switches have a LED indicator, allowing the limit values to be adjusted on site without any problems. Switching amplifiers (transistor relays) must be connected in the output circuit of the inductive alarm contacts A1/A2 in such a way that they meet the operational requirements of any connected control and signalling devices A1 p 2 ( ) (+) p 1 p 2 p 1 Fig. 3 Functional diagram of the indicator with 2 alarm contacts 1 Differential pressure cell 1.1 Housing of dp-cell 1.2 High pressure chamber 1.3 Low pressure chamber 1.4 Measuring springs (6 per measuring range) 1.5 Measuring diaphragm 1.6 Diaphragm plates 1.7 Diaphragm rod 1.8 Lever 1.9 Flexible disk A Indicating unit 2.1 Transmission element 2.2 Pointer mechanism 2.3 Scale 2.4 Pointer 3 Limit switch 3.1 Measuring unit shaft 3.2 Metal tags 3.3 Alarm contacts A1/A2 4 Valve block 4.1 Valve block with pressure gauge, shut-off valves, screw joints and test connection 2 T 9519 EN

3 Limit switch (alarm contacts A1, A2, A3) Proximity switches (NC, normally closed) Metal tag outside inductive field Switching signal "ON" (L-signal of the proximity switch) - Function: contact closed or output activated - Low resistive (undamped), power consumption 3 ma Adjustment range 1.1 Alarm contact A1 Adjustment range Adj. range 2.1 Alarm contact A3 Adj. range 2.2 Alarm contact A2 Metal tag inside inductive field Switching signal "OFF" (0-signal of the proximity switch) - Function: contact open or output disabled - Highly resistive (damped), power consumption 1 ma A1 = 1st min. contact A2 = 2nd min. contact A3 = max. contact Fig. 4 Limit switch with 3 alarm contacts in the indicating unit Table 1 Functions of the alarm contacts A1 and A2 Overview of functions Proximity switch for... Tapping of gas (min. contact) Adjustment ranges Filling of tank (max. contact) Alarm contacts A1 A2 A1 A2 Metal tag inside field Metal tag outside field Limit switch with 2 alarm contacts - Terminal assignment - LED1 LED Table 2 Functions of the alarm contacts A1, A2, A3 Overview of functions Proximity switch for... Adjustment ranges Tapping of gas (2 min. contacts) Filling of tank (1 max. contact) Alarm contacts A1 A2 A3 Activation when metal tag inside field Switching points Min. contacts when indication decreases Max. contacts when indication increases + + A1 A2 Fig. 5 Terminal assignment of A1 and A2 Limit switch with 3 alarm contacts - Terminal assignment - LED1 LED2 LED3 Table 3 Technical data for limit switch in type of protection EEx ia IIc T6 Maximum values for connection to certified intrinsically safe circuits U 0 16 V I K 52 ma P 169 mw Max. values at terminals 41/42; 45/46; 51/52 Effective internal inductance L i 250 µh Effective internal capacitance C i 50 nf Temperature class T6 T5 T4 Perm. ambient temperature 60 C 75 C 80 C A1 A2 A3 Fig. 6 Terminal assignment of A1, A2, A3 3 T 9519 EN

4 Table 2 Technical data All pressures in bar or mbar (gauge) Differential pressure meter Measuring range mbar ) Measuring span min to max Nominal pressure PN 40 1), overloadable on one side up to 40 bar Indicator 160 Performance Indicator linear to differential pressure Terminal-based non-conformity < ± 2.5 % < æ1.6 % (including hysteresis) Sensitivity < 0.5 % < 0.25 % Effect of static pressure < 0.03 % / 1 bar Limit switch unit Max. 3 alarm contacts A1/A2/A3 with proximity switches and LC display (acc. to Namur and DIN 19234) Control circuit Rating according to the connected transistor relay 2) Proximity switch 3) Type SJ 3.5N-LED 4) Switching accuracy < ±2 % Range of inversion, approx. < 0.6% Perm. ambient temperature range for oxygen C C Perm. storage temperature range C Degree of protection acc. to DIN IP 54 Weight Without valve block With valve block Approx. 3.0 kg Approx. 5.0 kg 1) Oxygen version for nominal pressure of up to PN 50 available on request. 2) For example WE77/Ex 2 or from the K system KFA6-SR2-Ex2.W. 3) Proximity switches can be used in hazardous areas, corresponding to the Certificate of Conformity PTB No. Ex-95.D.2195X. 4) Other limit switches available on request. Note: All errors and deviations are given in % of the adjusted measuring span. For flow measurement, see Data Sheet T 9550 EN. The technical data related to the special version are the same as for the standard version. Table 3 Materials (WN = Material Number according to DIN) Version Standard version Special version Housing of differential pressure cell Cu Zn 40 Pb CrNi-steel Measuring diaphragm and seals ECO Measuring springs Diaphragm plates and function parts CrNi-steel Lever Housing of indicating unit Polycarbonate 4 T 9519 EN

5 Installation (see Fig. 6) Tube mounting - With mounting device and clamp for attaching to a vertical or horizontal 2" tube. Wall/panel mounting Through two M 8 tapped holes located in the valve block or on the rear cover of the dp-cell. Panel mounting With either cheese head screws M 4 and thread M 4 in the panel or hexagon head screws with M 4 nuts (see Fig. 7/panel mounting). Process medium connection: Tapped hole ISO 228 G 3 8. Installation and dimensions in mm Tube mounting Mounting device Vertical tube Horizontal tube Clamp Press. gauge NG 100, AB-Wesel Dimensions in mm Safety version a b S1 EN S3 EN SW17 b a Wall mounting Panel mounting Panel cut-out Ø ,2-0,3 Center line of the indicating unit Holes 8.5 for fastening screws M 8 Ø Cut-out 52 Six tapped holes M 4 or holes with 4.5, for hexagon head screws with nuts M 4 Option of using either 3 x 120 or 4 x 90. Fig. 7 Dimensions 5 T 9519 EN

6 Ordering text Differential Pressure Meter/Flow Meter Media 5 Nomenclature for ordering: - Complete the order number according to the instrument version chosen - Instrument version Order No A - Media 5, dp cell CuZn40Pb2 0 Media 5, dp cell WN ) 1 Standard version 0 Version free of oil and grease for oxygen 2) acc. to standard , Page 1 1 Measuring range Measuring span Min. Max mbar 40 mbar 60 mbar mbar 50 mbar 100 mbar mbar 80 mbar 160 mbar mbar 125 mbar 250 mbar mbar 200 mbar 400 mbar mbar 300 mbar 600 mbar mbar 500 mbar 1000 mbar mbar 800 mbar 1600 mbar mbar 1250 mbar 2500 mbar mbar 2000 mbar 3600 mbar 2 3 Zero adjustment screw with zero point correcting screw (standard version) 0 with covered zero point correcting screw 1 Limit switch unit 3) without limit contacts 0 with 2 inductive limit contacts, Type SJ 3.5N-LED with 3 inductive limit contacts, Type SJ 3.5N-LED 2 3 Additionally required order specifications Measured value adjustment 4) Unit adjusted to:... mbar Additionally required order specifications Alarm contacts Contact A1 Contact A2 Contact A3 Min. contacts = measured value decreases Metal tag is inside outside inside outside inside outside Max. contacts = measured value increases For measured value 1) Special version available on request. 2) Version for oxygen up to nominal pressure PN 50 on request. 3) For limit switch unit from factory. Standard: without adjustment. 4) For measured value adjustment from factory. Standard: 0... max. measured value. For switching value...mbar... mbar... mbar Scale version required (see T 9545 EN), Accessories: valve block, pressure gauge, screw joints (see T 9555 EN) Specifications subject to change without notice. 1fNORMAL.STY@ADRESSE = SAMSON AG MESS- UND REGELTECHNIKWeismüllerstraße 3 D Frankfurt am MainTelefon (0 69) T 9519 EN