Model WEP Electro-pneumatic positioner. WEP positioner A valve control without compromise

Transcription

1 Data Sheet DS/WEP-EN Rev. C Model WEP Electro-pneumatic positioner WEP positioner A valve control without compromise Standard - ma input Single acting, force-balance operating principle Excellent dynamic response short positioning time and negligible positioning error Field adjustable for valve strokes between mm and mm (/ in and in) Accurate means of split-ranging the signal and/or selecting the valve action Set and forget reliability Complies with relevant international standards for test procedures, environmental protectionagainst harsh plant conditions Single feedback cam with three standardcharacteristics

2 Model WEP, identifies the valve positioner of the P Series of field mounting instruments; it consists of two functional parts: the input stage accepts a - ma signal and produces a corresponding -5 pneumatic signal used by the positioning section. WEP positioner ensures that the control valve plug position is always directly proportional to the input signal, regardless of diaphragm actuator hysteresis, packing-box friction or offbalance force on the valve plug. The valve responds to infinitely small changes in the controller output signal when process lags require the use of wide proportional band. Problems usually associated with plant instability due either to oversized valves or non-linear trim characteristics are minimized by selecting one of the three feedback cam alternative positions. Turn-down ratio to by a single controller output signal split ranging for sequential operation of two or more control valves is standard. FUNCTIONAL SPECIFICATIONS Input signal to ma dc Split-range Any value up to 5% of specified input range Output to actuator Up to 95% of auxiliary supply pressure; direct or reverse acting selectable on the positioning section Cam characteristics See figure. Linear, quadratic or square root pattern. Special characterization is available on request. PERCENT INSTRUMENT PRESSURE SPAN 8 6 Direct acting positioner 6 8 PERCENT VALVE STEM TRAVEL 6 8 Reverse acting positioner Linear cam Square root cam Quadratic cam Input resistance < 7 Ω Auxiliary air supply pressure (instrument air). to, to, to 6 Auxiliary supply static supply : 5 Nl/h (. 75,.75, supply : 6 Nl/h (.8 6 supply : 56 Nl/h (. scfm) Flow capacity supply: - input increasing: up to 9 Nl/h - input decreasing: up to 9 75,.75, supply: - input increasing: up to 6 Nl/h - input decreasing: up to 9 6 supply: - input increasing: up to 8 Nl/h - input decreasing: up to 9 Nl/h Ambient temperature: Reference : +5 to +5 C ± C (+59 to +77 F ± F) Operative limits : - and +85 C (- and +85 F) Relative humidity : Reference : 5% to 65% RH rmal, operative, transport/storage limits : to % RH condensing permissible Barometric pressure : Reference : 96, 96 m, 7 mmhg ±% rmal, operative, transport/storage limits : atmospheric pressure Vibration (IEC 65-) : Reference : none rmal, operative limits : severity class steady state - f = to Hz; displ..5 mm - acc..5 g - f = to 6 Hz; displ..5 mm - f = 6 to 5 Hz - acc. g Start point and span adjustments Separate, continuous, internal on the positioning section Stroke length Any value between mm and mm (/ in and in) providing feedback lever rotation is 5

3 6 6 PERFORMANCE SPECIFICATIONS (Reference conditions, - ma standard input range, standard linear cam and direct acting positioner. Unless otherwise specified errors, are quoted as % of span) Accuracy ± % (includes combined effects of non-linearity, hysteresis and repeatability). Indication accuracy: ± % f.s.d. Operating influences Ambient temperature per K (8 F) change between the limits of - and +6 C (- and + F) Zero error: ±.% of span Span error: ± % of reading Double the effect between the limits of - and - C (- and - F) or +6 and +85 C (+ and +85 F) Auxiliary supply per 5, 5 m, 5 change Total effect (zero and span) : ± % Humidity and ometric pressure : no effect EMI/RFI Comply with EN 58-/EN 58- requirements and tests; CE marking. Mounting position Total effect with reference to figures below: ±% for a tilt of ±9 from α axis +7% for a tilt of -9 from ß axis -% for a tilt of +9 from ß axis FRONT VIEW α PHYSICAL SPECIFICATIONS Materials Manifold, I/P converter housing and cover, positioner section case Low-copper content aluminium alloy with baked epoxy finish; AISI 6 ss. Positioner section cover P.T.B. - glass fibre reinforced polibutilentereftalathe, impact - resistant self-extinguishing polyester. Colour: red RAL Input bellows: Brass; AISI 6 ss. Other internal parts: AISI series ss Identification tag AISI 6 ss permanently mounted - characters max (legend to be specified) Gauges Brass with stainless steel case or AISI 6 ss, as specified Optional extras Supply and output Gauges Ext. dia mm indication on 6 (66 mm long) scale. - / - / -6 Airset with/without gauge Environmental protection Wet and dust-laden atmospheres The instrument is weatherproof and completely enclosed to IP 55 according to IEC59 (IP 65 for I/P converter). Pneumatic connections Supply and output / in NPT female Electrical connections One / NPT or Mx.5 or PG.5 or / GK threaded conduit entry, direct on converter housing SIDE VIEW (ß) Terminal block Two terminals for signal wiring up to.5 mm on converter unit. Net weight.5 kg approx. (5.5 lb) aluminium case version without optional extras Packing: Cardboard box -9 +9

4 ORDERING INFORMATION Select one character or set of characters from each category and specify complete catalog number. PRODUCT CODE abc d e f g h i j k lm BASE MODEL ELECTRICAL CERTIFICATION MATERIALS OF CONSTRUCTION INPUT SIGNAL RANGE ELECTRICAL CONNECTION SPRING PRESSURE RANGE OF THE ACTUATOR PRESSURE GAUGES CAM CHARACTERISTIC ACTION PRESETTING abc BASE MODEL - st to rd characters Electro-pneumatic positioner Code WEP d ELECTRICAL CERTIFICATION - th character t certified e MATERIALS OF CONSTRUCTION - 5th character Input bellows and relevant parts Brass AISI 6 ss Case Aluminium Aluminium Positioner case cover Polyester Polyester f INPUT SIGNAL RANGE - 6th character to ma dc to ma dc, Split range to ma dc, Split range 6 g ELECTRICAL CONNECTION - 7th character /" NPT - f /" GK - f M x.5 - f Pg.5 - f 5 h SPRING PRESSURE RANGE OF THE ACTUATOR - 8th character to 5 to. to i PRESSURE GAUGES - 9th character Output Supply te : The material of the case is Stainless Steel Materials (te) - - Brass Brass AISI 6 ss AISI 6 ss 5 j CAM CHARACTERISTIC - th character Standard k ACTION PRESETTING - th character Direct action Reverse action 5 lm th to th characters Use code

5 "Ex" Safety marking label DIMENSIONS (not for construction unless certified) Supply gauge I/P converter unit Output gauge Electrical connection 5 Min. clearance to remove the cover Exhaust Serial number tag Pneumatic positioner section Identification tag Exhaust External earth connection PNEUMATIC AND ELECTRIC CONNECTIONS Internal earth connection I/P module Electrical cable entry Input current signal Terminal block 5 Supply pressure 6 6 Output pressure I/P converter section

6 Contact us ABB Ltd. Howard Road St. Neots Cambridgeshire PE9 8EU UK Tel: + ()8 75 Fax: + ()8 798 ABB Inc. 5 E. County Line Road Warminster PA 897 USA Tel: Fax: te We reserve the right to make technical changes or modify the contents of this document without prior notice. With regard to purchase orders, the agreed particulars shall prevail. ABB does not accept any responsibility whatsoever for potential errors or possible lack of information in this document. We reserve all rights in this document and in the subject matter and illustrations contained therein. Any reproduction, disclosure to third parties or utilization of its contents - in whole or in parts is forbidden without prior written consent of ABB. Copyright ABB All rights reserved DS/WEP-EN Rev. C. ABB Automation Products GmbH Schillerstr. 7 5 Minden Germany Tel: Fax: ABB S.p.A. Via Statale 6 Lenno (CO) Italy Tel: Fax: