Yokogawa In-Situ Type Zirconia Oxygen Analyzer Model ZO21DW Detector User's Manual

User’s Manual In-Situ Type Zirconia Oxygen Analyzer Model ZO21DW Detector IM 11M03A02-00E IM 11M03A02-00E 2nd Edition   INTRODUCTION The zirconia oxygen analyzer is used for monitoring and controlling the combustion conditions of processes in all fields which require combustion control. This zirconia oxygen analyzer features the direct measurement of the oxygen concentration in a furnace by inserting the detector into the furnace. However, for accurate measurement, it is preferable that there be no pressure difference between the measuring gas in contact with the sensor anode and the reference gas supplied on the cathode side. The Model ZO21DW zirconia oxygen detector is constructed in such a way that the reference gas outlet is open to the inside of the furnace. Hence, the measured gas and reference gas pressures can be kept at about the same level, making high accuracy measurements possible. This instruction manual describes all the handling and operations of the Model ZO21DW Zirconia Oxygen Detector, including installation, wiring, running, inspection, maintenance, etc. Read it thoroughly before handling the detector in order to get a full demonstration of its performance. For handling the converters associated with this detector, see the corresponding instruction manual. Before using the instruments, read any descriptions related to your instruments and system to ensure the best performance. User’s manual of instrument related to the ZO21DW is as follows: Model ZR402G Title Separate Type Zirconia Oxygen Analyzer Media No. IM 11M03A02-00E 2nd Edition : Aug. 2009 (KP) All Rights Reserved Copyright © 2009, Yokogawa Electric Corporation Manual No. IM 11M12A01-02E IM 11M03A02-00E ii  For the safe use of this equipment CAUTION The cell (sensor) at the tip of the detector is made of ceramic (zirconia element). Do not drop the detector or subject it to pressure stress. • Do NOT allow the sensor (probe tip) to make contact with anything when installing the detector. • Avoid any water dropping directly on the probe (sensor) of the detector when installing it. • Check the calibration gas piping before introducing the calibration gas to ensure that there is no leakage of the gas. If there is any leakage of the gas, the moisture drawn from the measured gas may damage the sensor. • The detector (especially at the tip) becomes very hot. Be sure to handle it with gloves. DANGER The product is very heavy. Handle it with care. Be sure not to accidentally drop it. Handle safely to avoid injury. Connect the power supply cord only after confirming that the supply voltage matches the rating of this equipment. In addition, confirm that the power is switched off when connecting power supply. Some process gas is dangerous to people. When removing this equipment from the process line for maintenance or other reasons, protect yourself from potential poisoning by using a protective mask or ventilating the area well. (1) About This Manual • This manual should be passed on to the end user. • The contents of this manual are subject to change without prior notice. • The contents of this manual shall not be reproduced or copied, in part or in whole, without permission. • This manual explains the functions contained in this product, but does not warrant that those will suit the particular purpose of the user. • Every effort has been made to ensure accuracy in the preparation of this manual. However, should any errors or omissions come to the attention of the user, please contact the nearest Yokogawa Electric representative or sales office. • This manual does not cover the special specifications. This manual may not be changed on any change of specification, construction and parts when the change does not affect the functions or performance of the product. • If the product is used in a manner not specified in this manual, the safety of this product may be impaired. IM 11M03A02-00E  iii (2) Safety and Modification Precautions • Follow the safety precautions in this manual when using the product to ensure protection and safety of personnel, product and system containing the product. (3) The following safety symbols are used on the product as well as in this manual. DANGER This symbol indicates that the operator must follow the instructions laid out in this manual in order to avoid the risk of personnel injury electric shock, or fatalities. The manual describes what special care the operator must exercise to avoid such risks. WARNING This symbol indicates that the operator must refer to the instructions in this manual in order to prevent the instrument (hardware) or software from being damaged, or a system failure from occurring. CAUTION This symbol draws attention to information essential for understanding the operation and functions. Tip This symbol gives information that complements the present topic. SEE ALSO This symbol identifies a source to which to refer. Protective Ground Terminal Function Ground Terminal (Do not use this terminal as the protective ground terminal.) Alternating current IM 11M03A02-00E iv  After-sales Warranty n Do not modify the product. n During the warranty period, for repair under warranty carry or send the product to the local sales representative or service office. Yokogawa will replace or repair any damaged parts and return the product to you. Before returning a product for repair under warranty, provide us with the model name and serial number and a description of the problem. Any diagrams or data explaining the problem would also be appreciated.  If we replace the product with a new one, we won’t provide you with a repair report.  Yokogawa warrants the product for the period stated in the pre-purchase quotation Yokogawa shall conduct defined warranty service based on its standard. When the customer site is located outside of the service area, a fee for dispatching the maintenance engineer will be charged to the customer. n In the following cases, customer will be charged repair fee regardless of warranty period. • Failure of components which are out of scope of warranty stated in instruction manual. • Failure caused by usage of software, hardware or auxiliary equipment, which Yokogawa Electric did not supply. • Failure due to improper or insufficient maintenance by user. • Failure due to modification, misuse or outside-of-specifications operation which Yokogawa does not authorize. • Failure due to power supply (voltage, frequency) being outside specifications or abnormal. • Failure caused by any usage out of scope of recommended usage. • Any damage from fire, earthquake, storms and floods, lightning, disturbances, riots, warfare, radiation and other natural changes. n Yokogawa does not warrant conformance with the specific application at the user site. Yokogawa will not bear direct/indirect responsibility for damage due to a specific application. n Yokogawa Electric will not bear responsibility when the user configures the product into systems or resells the product. n Maintenance service and supplying repair parts will be covered for five years after the production ends. For repair for this product, please contact the nearest sales office described in this instruction manual. IM 11M03A02-00E  Model ZO21DW Detector In-Situ Type Zirconia Oxygen Analyzer IM 11M03A02-00E 2nd Edition CONTENTS INTRODUCTION........................................................................................................i  For the safe use of this equipment....................................................................ii  After-sales Warranty...........................................................................................iv 1. 2. 3. SPECIFICATIONS...................................................................................... 1-1 1.1 Standard Specifications.................................................................................... 1-1 1.2 Model and Codes............................................................................................... 1-2 1.3 External Dimensions......................................................................................... 1-3 INSTALLATION.......................................................................................... 2-1 2.1 Installation Site................................................................................................... 2-1 2.2 Probe Insertion Hole.......................................................................................... 2-1 2.3 Detector Installation.......................................................................................... 2-2 PIPING........................................................................................................ 3-1 3.1 3.2 3.3 4. Piping for System 1............................................................................................ 3-1 3.1.1 Parts Required for Piping in System 1................................................ 3-2 3.1.2 Connection to the Calibration Gas Inlet.............................................. 3-2 3.1.3 Piping for the Reference Gas Inlet...................................................... 3-3 Piping for System 2............................................................................................ 3-4 3.2.1 Piping Parts for System 2................................................................... 3-5 3.2.2 Piping for the Calibration Gas............................................................. 3-5 3.2.3 Piping for the Reference Gas............................................................. 3-6 3.2.4 Valve Operation of Reference Gas Outlet.......................................... 3-6 Piping for System 3............................................................................................ 3-7 WIRING....................................................................................................... 4-1 4.1 4.2 General................................................................................................................ 4-1 4.1.1 Cable Specification............................................................................. 4-1 4.1.2 Wiring Procedure................................................................................ 4-2 Wiring for Detector Output................................................................................ 4-3 4.2.1 4.3 Wiring for Power to Detector Heater................................................................ 4-4 4.3.1 4.4 Connection to the Detector................................................................. 4-3 Connection to Detector....................................................................... 4-4 Power and Grounding Wiring........................................................................... 4-5 4.4.1 Power Wiring....................................................................................... 4-5 4.4.2 Grounding Wiring................................................................................ 4-5 IM 11M03A02-00E vi 5. NAME AND FUNCTION OF COMPONENTS............................................ 5-1 6. OPERATION............................................................................................... 6-1 6.1 6.2 7. Start-Up............................................................................................................... 6-1 6.1.1 Inspection of Piping and Wiring Conditions........................................ 6-1 6.1.2 Checking of Set Valves....................................................................... 6-1 6.1.3 Supplying Heater Power..................................................................... 6-1 6.1.4 Calibration........................................................................................... 6-1 Stationary Operation......................................................................................... 6-2 6.2.1 Checking Operating Conditions.......................................................... 6-2 6.2.2 Stopping and Restarting Operations.................................................. 6-2 INSPECTION AND MAINTENANCE......................................................... 7-1 7.1 Inspection and Maintenance of the Detector.................................................. 7-2 7.1.1 Cleaning the Calibration Gas Tube..................................................... 7-2 7.1.2 Replacing the Sensor Assembly......................................................... 7-3 7.1.3 Stopping and Re-starting Operation................................................... 7-6 Customer Maintenance Parts List.......................................CMPL 11M06B02-01E Revision Information................................................................................................i IM 11M03A02-00E  1. 1-1 <1. SPECIFICATIONS> SPECIFICATIONS In this chapter, the specifications of the ZO21DW detector is described. 1.1 Standard Specifications The probe, as a whole, is not explosion-protected (Calibration gas inlet, reference gas outlet) and only its terminal box section is explosion-protected. Sample Gas Temperature: 0 to 600°C Sample Gas Pressure: -20 to +20 kPa Insertion Length: 0.4, 1.0, 1.5, 2.0, 3.0 m Ambient Temperature: -10 to +70°C (terminal box temperature) Reference-air Flow Rate: 800 ml/min. (Use instrument air. Reference gas is discharged into the furnace.) Material in Contact with Gas: SUS316, Zirconia, SUS304 (flange) Installation: Flange mounting Probe mounting angle; Between the horizontal and vertically down positions Note: Probe protector (ZO21R-L-150-∗B/R, GS11M12A01-01E) is required when insertion length is 3 m and horizontal installation. Joint; Rc1/8 Flange; JIS 10K-100-FF SUS304, ANSI Class 150-4-RF SUS304, and DIN PN10 DN100-4 SUS304. Construction: The terminal box of ZO21DW flameploof specification 　　　　TIIS flameploof type certification 　　　　Protection Concept: d2G4 Weight: With insertion length of 0.4 m, approx. 6.5 kg; 1.0 m, approx. 10.0 kg; 1.5 m, approx. 13.0 kg; 2.0 m, approx. 17.0 kg; 3.0 m, approx. 20.0 kg IM 11M03A02-00E 1-2 <1. SPECIFICATIONS> 1.2 Model and Codes Model ZO21DW Insertion length Suffix code -L · · · · · · · · · · · · · · · · · · · Description · · · · · · · · · · Probe with flameproof terminal box -040 · · · · · · · · · · · · · · · · · · · · · · · 0.4m -100 · · · · · · · · · · · · · · · · · · · · · · · 1.0m -150 · · · · · · · · · · · · · · · · · · · · · · · 1.5m -200 · · · · · · · · · · · · · · · · · · · · · · · 2.0m -300 · · · · · · · · · · · · · Flange joint connection Option code · · · · · · · · · · 3.0m -J · · · · · · · · · · · · · · · · · · · · · JIS 10K-100-FF SUS304 -A · · · · · · · · · · · · · · · · · · · · · ANSI Class 150-4-RF SUS304 -E · · · · · · · · · · · · · · · · · · · · · DIN PN10 DN100-4 SUS304 Style code *A · · · · · · · · · Options · · · · · · · · · · Style A /CV · · · · · · With check valve /SV · · · · · · With stop valve /G Cable glands (2 pieces)　(Note1) ······ Note1: Cable gland [/G] must be specified when installed in hazardous area. IM 11M03A02-00E Name Part No. Description CABLE GLAND G7272YE Matal Fittings with resisting pressure. O. D.ø11 to ø13 <1. SPECIFICATIONS> 1-3 External Dimensions Unit : mm L ( *) 315±5 Flange C Calibration gas inlet Rc 1/8 øB øA t Reference gas inlet Rc 1/8 ( *) L = 400, 1000, 1500, 2000, 3000 (mm) ø150 Terminal box Approx. 210 48 1.3 ø42.7 Reference gas return 2-G3/4 Wiring hole F1.1E.ai Model and Suffix codes Length L (mm) Flange Flange A B C t Weight (kg) ZO21DW-L-040-J*A 400 Approx. 6.5 ZO21DW-L-100-J*A 1000 ZO21DW-L-150-J*A 1500 ZO21DW-L-200-J*A 2000 ZO21DW-L-300-J*A 3000 Approx. 20 ZO21DW-L-040-A*A 400 Approx. 6.5 ZO21DW-L-100-A*A 1000 ZO21DW-L-150-A*A 1500 ZO21DW-L-200-A*A 2000 ZO21DW-L-300-A*A 3000 Approx. 20 ZO21DW-L-040-E*A 400 Approx. 6.5 ZO21DW-L-100-E*A 1000 ZO21DW-L-150-E*A 1500 ZO21DW-L-200-E*A 2000 ZO21DW-L-300-E*A 3000 JIS 10K-100-FF ( or equivalent ) ANSI CLASS 150-4-RF ( or equivalent ) DIN PN10-DN100-4 ( or equivalent ) 210 175 228.6 190.5 220 180 8 - ø19 8 - ø19 8 - ø18 Approx. 10 18 Approx. 13 Approx. 17 Approx. 10 24 Approx. 13 Approx. 17 Approx. 10 20 Approx. 13 Approx. 17 Approx. 20 IM 11M03A02-00E Blank Page  2-1 <2. INSTALLATION> 2. INSTALLATION 2.1 Installation Site The following should be taken into consideration when installing the detector : (1) Easy access to the detector for checking and maintenance work. (2) A location in which the ambient temperature is not too high (below 70°C) and the terminal box is not subject to radiant heat. (3) A clean environment without any corrosive gases. (4) No vibration. 2.2 Probe Insertion Hole When preparing the probe insert hole, the following should be taken into consideration : CAUTION • The outside dimension of detector may vary depending on its options. Use a pipe that is large enough for the detector. • If the detector is mounted horizontally, the calibration gas inlet and reference gas inlet should face downwards. • When using the detector with pressure compensation, ensure that the flange gasket does not block the reference gas outlet on the detector flange. If the flange gasket blocks the outlet, the detector cannot conduct pressure compensation. Where necessary, make a notch in the flange gasket. • The sensor (zirconia cell) at the probe tip may deteriorate due to thermal shock if water drops are allowed to fall on it, as it is always at high temperature. (1) The detector probe tip should not be pointed upward. Note : If the probe tip is placed upward, the cell (sensor) in the probe tip may deteriorate due to condensation. (2) If the insertion probe length is more than 2.5 meters, the detector should be attached almost vertically (no more than a 5 tilt). (3) The detector probe should be situated almost at a right angle to the gas flow to be analyzed or, at the very least, the probe tip should be on the down flow side. IM 11M03A02-00E 2-2 <2. INSTALLATION> (vertical) Bounds of the probe insertion hole location Flange matches the detector specifiions 100 mm (horizontal) Greater than ø52 mm 100 mm Eight-hole flange F2.1E.ai Note : Make sure the reference gas outlet of the detector is not blocked by the gasket on the flange surface. Figure 2.1 Example of probe insertion hole 2.3 Detector Installation CAUTION The cell (sensor) at the tip of the detector is made of ceramic (zirconia). Do not drop the detector, as inpact will damage it. The gasket should be used on the flange surface to prevent gas leakage. The gasket material should be heatproof and corrosion-proof. The following should be taken into consideration when mounting the detector : (1) Make sure the cell mounting screws (four pcs.) have not come loose. (2) In a case where the detector is attached horizontally, the cable lead-in hole should face downward. IM 11M03A02-00E  3. 3-1 <3. PIPING> PIPING This chapter describes the line - installation procedures for two typical system configurations of the zirconia oxygen analyzer using the ZO21DW detector. CAUTION • Ensure that each check valve, stop valve and joint used for piping do not allow leakage. Especially, if there is any leakage of the calibration gas from pipes and joints, it may cause clogging of the pipes or incorrect calibration. • Be sure to conduct leakage test after piping. • Basically, apply instrument air (dehumidified by cooling to the dew point -20°C or lower, and removing any dust, oil mist and the like) for the reference gas. System 1 : Instrument air is used as the reference gas. Calibration is carried out manually with the portable ZO21S standard gas unit. The zero gas and span gas (air) are supplied from the standard gas unit to the detector by connecting the tube only when it is calibrated. System 2 : Instrument air is used as the reference gas. This instrument air is also used as the span gas in calibration. The zero gas in calibration is supplied from the zero gas cylinder. System 3 : Basically the same as system 2. However, calibration is carried out automatically with the converter which has a calibration-execution command function. 3.1 Piping for System 1 The piping in System 1 is illustrated in Figure 3.1. Model ZR402G Converter ZO21DW Zirconia Oxygen Analyzer, Detector EXA ZR402G Stop valve Signal (6-core shield cable) ~ Heater (2-core) flowmeter Needle Air Set valve Reference gas 100 to 240 V AC Contact input Analog output, Contact output Digital output (HART) Instrument air Model ZO21S Standard gas unit Calibration gas ~ 100/110/115 200/220/240 V AC F3.1E.ai Figure 3.1 Piping for System 1 Piping in System 1 is as follows : • Place a stop valve through a nipple at the calibration gas inlet of the detector, and mount a joint for a ø6 × ø4 mm soft tube at the stop valve connection hole of the inlet side (see Section 3.1.2). The tube is to be connected to this joint only during calibration. IM 11M03A02-00E 3-2 <3. PIPING> CAUTION • The stop valve should be connected directly to the detector. If any piping is present between the detector and the stop valve, water may condense in the pipe, which may cause damage to the sensor by rapid cooling when the calibration gas is introduced. The stop valve should be closed except while the calibration gas is being introduced. • The reference gas should have an oxygen concentration identical to that of fresh air (21%). 3.1.1 Parts Required for Piping in System 1 Check that the parts listed in Table 3.1 are ready. Table 3.1 Parts required for piping Piping section At the calibration gas inlet At the reference gas inlet Parts required Description Stop valve Recommended by YOKOGAWA (L9852CB or G7016XH) * Nipple Rc 1/4 or 1/4 NPT On the open market Tube connecting joint Rc 1/4 (1/4 NPT) – ø6 × ø4 mm soft tube On the open market Air set Recommended by YOKOGAWA (K9473XH/K9473XJ) Piping joint Rc 1/4 or 1/4 NPT On the open market Note : The parts with an asterisk (*) may not be required. 3.1.2 Connection to the Calibration Gas Inlet When carrying out calibration, connect the piping (ø6 × ø4 mm tube) from the standard gas unit to the calibration gas inlet of the detector. First, mount a stop valve (of a quality specified by YOKOGAWA) on a nipple (found on the open market) as illustrated in Figure 3.2, and mount a joint (also found on the open market) at the stop valve tip. (The stop valve may be mounted on the detector prior to shipping the detector.) Note 1: Mount the stop valve close to the detector. Stop valve Nipple Tube connection joint F4.2E.EPS Figure 3.2 Connection to the calibration gas inlet IM 11M03A02-00E  3-3 <3. PIPING> 3.1.3 Piping for the Reference Gas Inlet Reference gas piping is required between the air source (fresh air) and the flow setting unit and between the flow setting unit and the detector. Insert the air set next to the flow setting unit in the piping between the air source and the flow setting unit. Use a ø6 × ø4 mm (or nominal size 1/4 inch) stainless steel pipe between the flow setting unit and the detector. IM 11M03A02-00E 3-4 <3. PIPING> 3.2 Piping for System 2 Piping in System 2 is illustrated in Figure 3.3. ZO21DW Zirconia Oxygen Analyzer, Detector Model ZR402G Converter EXA ZR402G Signal (6-core shield cable) Stop valve or Check valve ~ Heater (2-core) Reference gas flowmeter Needle valve 100 to 240 V AC Contact input Analog output, Contact input Digital output (HART) Air Set Instrument air Span gas (Same as Zero gas Calibration) Calibration gas Calibration gas pressure regulator Model ZA8F flow setting unit Zero gas cylinder Calibration gas unit case F3.3E.ai Figure 3.3 Piping for System 2 System 2 illustrated in Figure 3.3 requires piping as follows : • Mount the check valve or stop valve through a nipple to the reference gas inlet of the detector. CAUTION The stop valve should be connected directly to the detector. If any piping is present between the detector and the stop valve, condensed water may be produced in the pipe, which may cause damage to the sensor by rapid cooling when the calibration gas is introduced. • Supply air pressure (flow) may vary depending on the furnace pressure. It is recommended to use a flow gauge and an air set that is suitable for the furnace pressure. CAUTION • When using the ZA8F Flow Setting Unit and ZR40H Automatic Calibration Unit, please note that the supplying airflow (pressure) will vary depending on the furnace pressure. IM 11M03A02-00E  3-5 <3. PIPING> 3.2.1 Piping Parts for System 2 Check that the parts listed in Table 3.2 are ready. Table 3.2 Piping parts Piping section Calibration gas piping At the reference gas inlet Parts required Description Stop valve or Check valve Recommended by YOKOGAWA (L9852CB or G7016XH for Stop valve, E7042VR or E7042VV for Check valve) * Nipple Rc 1/4 or 1/4 NPT Zero gas cylinder Recommended by YOKOGAWA (G7001ZC) Regulator valve Recommended by YOKOGAWA (G7013XF or G7014XF) Piping joint Rc 1/4 or 1/4 NPT Air set Recommended by YOKOGAWA (K9473XH/K9473XJ) Piping joint Rc 1/4 or 1/4 NPT On the open market On the open market On the open market Note : The parts with an asterisk (*) may not be required. 3.2.2 Piping for the Calibration Gas This piping is to be installed between the zero gas cylinder and the ZA8F flow setting unit, and between the ZA8F flow setting unit and the ZO21DW detector. The cylinder should be placed in a calibration gas unit case or the like to avoid any direct sunlight or radiant heat so that the gas cylinder temperature does not exceed 40°C. Mount a regulator valve (specified by YOKOGAWA) on the cylinder. Mount a check valve or stop valve (specified by YOKOGAWA) on the nipple (found on the open market) at the calibration gas inlet of the detector as illustrated in Figure 3.4. (The check valve or the stop valve may have been mounted on the detector when shipped.) Connect the flow setting unit and the detector to a stainless steel pipe ø6 × ø4 mm (or nominal size 1/4 inch). Stop valve or Check valve Piping for the Calibration gas, ø6 × ø4 mm Stainless steel pipe Piping for the Reference gas, ø6 × ø4 mm Stainless steel pipe F4.8E.EPS Figure 3.4 Check the valve connection to the calibration gas inlet IM 11M03A02-00E 3-6 <3. PIPING> 3.2.3 Piping for the Reference Gas Reference gas piping is required between the air source (instrument air) and the flow setting unit, and between the flow setting unit and the detector. Insert the air set next to the flow setting unit in the piping between the air source and the flow setting unit. Use a ø6 × ø4 mm (or nominal size 1/4 inch) stainless steel pipe between the flow setting unit and the detector. 3.2.4 Valve Operation of Reference Gas Outlet 1. For safety, stop the furnace that the detector is to be installed in. If furnace internal pressure is high, this is especially dangerous. 2. Before starting instrument air flow, completely shut the stop valve in front of the reference gas outlet. 3. Check that the reference gas outlet is not blocked by a flange gasket or the like. 4. Set the instrument air pressure higher than furnace internal pressure. 5. Completely open the stop valve in front of the reference gas outlet and, after turning on instrument air flow, start furnace operation. As furnace internal pressure rises, confirm that instrument air continues to flow and adjust the valve or increase supply pressure if necessary. 6. After furnace internal pressure stabilizes, adjust flow. 7. If furnace operation is stopped, stop instrument air flow and completely shut the stop valve in front of the reference gas outlet. You may leave reference gas flowing if you wish. IM 11M03A02-00E  3.3 <3. PIPING> 3-7 Piping for System 3 Piping in System 3 is illustrated in Figure 3.5. In System 3, calibration is automated but the piping is basically the same as that of System 2. See section 3.2. ZO21DW Zirconia Oxygen Analyzer, Detector Model ZR402G Converter EXA ZR402G Check valve Signal (6-core shield cable) Heater (2-core cable) flowmeter Reference gas Needle valve Calibration gas ~ 100 to 240 V AC Contact input Analog output, contact output Digital output (HART) Air Set Instrument air Calibration gas pressure regulator Zero gas cylinder Model ZR40H Auto Calibration unit Calibration gas unit case F4.9E.EPS Figure 3.5 Piping for System 3 IM 11M03A02-00E Blank Page  4. 4-1 <4. WIRING> WIRING In this Chapter, the wiring necessary for connection to the Model ZO21DW detector is described. 4.1 General CAUTION NEVER supply current to the converter or any other device constituting a power circuit in combination with the converter, until all wiring is completed. 4.1.1 Cable Specification Cable specifications are shown in Table 4.1. Table 4.1 Cable specifications Terminal name of converter Name Need for shields Cable type Number of wires  CVVS 6 Converter heater CVV 2 L, N, Power supply CVV 2 or 3 * AO-1+, AO-1-, AO-2+, AO-2- Analog output CVVS 2 or 4 DO-1, DO-2, DO-3, DO-4 Contact output CVV 2 to 8 AC-Z, AC-S, AC-C Automatic Calibration unit CVV 3 DI-1, DI-2, DI-C Contact input CVV 3 CELL+, CELLHTR TC+, HTR TCCJ+, CJ- Converter signal HEATER  Note *: When the case is used for protective grounding, use a 2 cores cable. CAUTION • Select suitable cable O.D. to match the cable gland size. • Protective grounding should be connected in ways equivalent to JIS D type (Class 3 grounding), (the grounding resistance is 100Ω or less). IM 11M03A02-00E 4-2 <4. WIRING> 4.1.2 Wiring Procedure Wiring should be performed according to the following procedure: 1. Be sure to connect the shield line to FG terminal of the converter. 2. The outer sheath of the signal line should be stripped to a length of 50 mm or less. The most outer sheath of the power cable should be stripped to a length of 20 mm or less. 3. Signals may be affected by noise if signal lines, power cable and heater cable are located in the same conduit. When using conduit, signal lines should be installed in a separate conduit than power and heater cables. 4. Install metal blind plug(s) in unused cable connection gland(s) of the converter. 5. Metal conduit should be grounded. Zirconia Oxygen Analyzer, Model ZO21DW Detector Model ZR402G Separate type Zirconia Oxygen Analyzer/ Converter Analog Analog output 1 4-20 mA DC output 2 Digital output 4-20 mA DC 1 FG 12 FG 2 3 4 5 6 7 8 9 10 11 AO1 AO1 AO2 AO2 CJ CJ TC TC CELL CELL (+) (-) (+) (-) (+) (-) (+) (-) (+) (-) 13 14 15 16 17 18 19 20 21 22 DI-1 DI-2 DI-C AI AI AC- AC- AC- FG FG (+) (-) ZERO SPAN COM Contact input 2 CELL CELL (+) (-) TC (+) TC (-) CJ (+) CJ (-) Solenoid valve for span gas for automatic calibration Contact input 1 Solenoid valve for zero gas for automatic calibration Flow setting unit 23 24 25 26 27 28 29 30 31 32 DO-1 DO-1 DO-2 DO-2 DO-3 DO-3 DO-4 DO-4 HTR HTR Contact output 1 Contact output 2 Contact output 3 Contact output 4 33 L 34 N 35 G 36 FG 100-240V AC 50/60 Hz HTR HTR *1 *1 *1 The protective grounding for the converter should be connected to either the protective ground terminal in the equipment or the ground terminal on the case. Grounding standard: JIS D type (Class 3 grounding), ground resistance: 100 Ω or less. F4.1E.ai Figure 4.1 Wiring connection to the converter (ZR402G) IM 11M03A02-00E  4.2 4-3 <4. WIRING> Wiring for Detector Output This wiring enables the converter to receive cell output from the detector, output from a thermocouple and a reference junction compensation signal. Install wires that allow for 10Ω of loop resistance or less. Keep detector wiring away from power wiring. Basically, PVC sheathed PVC insulated cable (six cores) is used for this wiring. ZR402G Converter Detector CELL(+) CELL(+) CELL(-) CELL(-) TC(+) TC(+) TC(-) CJ(+) TC(-) CJ(-) CJ(-) CJ(+) Shielded cables FG F4.2E.ai Figure 4.2 Wiring for detector output 4.2.1 Connection to the Detector To connect cables to the detector, proceed as follows: (1) Mount conduits of the specified thread size or cable glands to the wiring connections of the detector. The detector may need to be removed in future for maintenance, so be sure to allow sufficient cable length. (2) The sizes of the terminal screw threads are M3.5. Each wire in the cable should be terminated in the corresponding size of crimp terminal respectively. (3) Except when “600V silicon rubber insulated glass braided wire” is used, connect the cable shield to the FG terminal of the converter. IM 11M03A02-00E 4-4 <4. WIRING> 4.3 Wiring for Power to Detector Heater This wiring provides electric power from the converter to the heater for heating the sensor in the detector. Basically, PVC insulated PVC sheathed control cables (2 cores) are used for this wiring. Detector HTR 7 HTR 8 ZR402G Converter HEATER F4.3E.ai Figure 4.3 Wiring for power to the detector heater 4.3.1 Connection to Detector When connecting the cable to the detector, proceed as follows: (1) Mount cable glands or conduits of the specified thread size to the wiring connections of the detector. The detector may need to be removed in future for maintenance, so be sure to allow sufficient cable length. (2) The size of the terminal screw threads is M3.5. Each cable should be terminated in the corresponding size crimp-on terminals contact respectively. IM 11M03A02-00E  4.4 4-5 <4. WIRING> Power and Grounding Wiring This wiring supplies power to the converter and grounds the converter/detector. ZO21DW Detector ZR402G Converter Grounding to the ground terminal on the converter case L N G Converter case Jumper plate FG terminal Lock washer Crimp-on terminal of the ground wire 100 - 240VAC 50/60Hz Ground F4.4E.ai Figure 4.4 Power and Grounding wiring 4.4.1 Power Wiring Connect the power wiring to the L and N terminals of the converter. Proceed as follows: (1) Use a 2-core or a 3-core shielded cable. (2) The size of converter terminal screw threads is M4. Each cable should be terminated corresponding crimp-on terminals. 4.4.2 Grounding Wiring The ground wiring of the detector should be connected to the ground terminal of the detector case. The ground wiring of the converter should be connected to either the ground terminal of the converter case or the protective ground terminal in the equipment. The grounding terminals of the detector and the converter are of size M4. Proceed as follows: (1) Keep ground resistance to 100Ω or less. (2) When connecting the ground wiring to the ground terminal of the converter case, be sure that the lock washer is in contact with the case surface (see Figure 4.4.). (3) Ensure that the jumper plate is connected between the G terminal and the protective ground terminal of the converter. IM 11M03A02-00E Blank Page  5. 5-1 <5. NAME AND FUNCTION OF COMPONENTS> NAME AND FUNCTION OF COMPONENTS In this Chapter, the name and function of components are described for the ZO21DW detector. Flange Stop valve Vent pipe for reference air Probe Insert this part into the furnace. You can select a length of 0.4, 1.0, 1.5, 2.0 or 3.0 m. Terminal box Waterproof structure Calibration gas tube Sensor (cell) Filter Filter retainer Spring washer Bolt O ring (metallic) Contact Connects the positive pole of the sensor to the electric circuit in the probe. U-shaped pipe F5.1E.ai Figure 5.1 Name and Function of Each Component in the Detector IM 11M03A02-00E Blank Page  6. 6-1 <6. OPERATION> OPERATION This chapter describes the operations for running the system related only to the ZO21DW Detector. For the entire zirconia oxygen analyzer operation, see the instruction manual for the converter. 6.1 Start-Up 6.1.1 Inspection of Piping and Wiring Conditions In referring to Chapters 3 and 4, inspect the piping and wiring to see that they are correctly installed. 6.1.2 Checking of Set Valves Set up valves and associated components used in the analyzer system as follows: (1) If a stop valve is used in the detector's calibration gas inlet, fully close this valve. (2) If instrument air is used as the reference gas, adjust the air set secondary pressure so that an air pressure equals measured gas pressure plus approx. 50 kPa (or measured gas pressure plus approx. 150 kPa when a check valve is used, maximum pressure rating is 300 kPa) is obtained. Turn the reference gas flow setting valve in the flow setting unit to obtain a flow of 800 to 1000 ml/min. (Turning the valve shaft counterclockwise increases the rate of flow. Before turning the valve shaft, if the valve has a lock nut, first loosen the lock nut.) After completing the valve setup, be sure to tighten the lock nut. 6.1.3 Supplying Heater Power Supply power for the heater from the converter to the detector. Connect the power to the converter and turn ON the power switch in the converter. The time from turning ON the power to starting measurement after the sensor in the detector reaches the required temperature is about ten minutes. 6.1.4 Calibration The calibration procedure varies with the converter used. Carry out calibration according to the instruction manual for that converter. CAUTION When combining with the ZR402G converter, select the ZO21D as a detector in commissioning mode of the ZR402G. IM 11M03A02-00E 6-2 <6. OPERATION> 6.2 Stationary Operation 6.2.1 Checking Operating Conditions In order to maintain normal operating conditions, determine which items are to be inspected periodically, and check them regularly for errors. Items recommended for periodic inspections are as follows for your reference. For maintaining or recovering performance, see Chapter 7. Table 6.1 Example of Items for Periodic Inspection Inspection Item Purpose & detail of inspection Inspection System System System interval 1 2 3 Complete closing of calibration gas inlet To prevent condensation which may break sensor. Check for a complete closing of needle 1 to 7 days valve. Set flow rate of flow setting unit Check that flow is about 800 ml/min. and 600ml/min. for reference gas and calibration gas, respectively for correctly measured and calibrated values. Pressure in the calibration gas cylinder To determine the intervals between replacement of calibration gas (zero gas) cylinders. Specify min. pressure and check for higher pressure.  1 to 7 days   1 to 2 week   6.2.2 Stopping and Restarting Operations Before stopping operations, it is important for you not to make the detector sensor inoperable. If you stop the operation of the zirconia oxygen analyzer at the same time as the boiler or furnace, etc., condensation forms in the sensor and dust adheres to it. If you restart operations with the sensor in this state, as it heats up to 750°C, it causes dust to accumulate which significantly deteriorates its performance. In an extreme case with a lot of condensation, the analyzer may break. To prevent such an occurrence, you have to take the following steps to stop the equipment : (1) Do not stop to supply reference gas to keep the stop valve in the discharge tube of the reference gas open because the measuring gas may flow backward into the detector. (2) Keep the power supply to the analyzer ON as long as possible. If this is impossible, remove the detector. (3) If both of the above are impossible, keep air flowing into the calibration gas piping at a rate of about 600 ml/min. If none of the above precautions for stopping operations can be done, supply air into the calibration gas piping for 5 to 10 minutes at a rate of about 600 ml/min. IM 11M03A02-00E  7. 7-1 <7. INSPECTION AND MAINTENANCE> INSPECTION AND MAINTENANCE This chapter describes the inspection and maintenance procedures for the ZO21DW Zirconia Oxygen Analyzer to maintain its measuring performance and normal operating conditions. CAUTION When checking the detector, carefully observe the following: (1) Do NOT touch the probe if it has been in operation immediately just before being checked. (The sensor at the tip of the probe heats up to 750°C during operation. If you touch it, you will get burned.) (2) Do not subject the probe to shock or cool it rapidly. The sensor is made of ceramic (zirconia). If the detector is dropped or bumped into something, the sensor may be damaged and no longer work. (3) Do not reuse a metal O-ring to seal the cell assembly. If you replace the cell or remove it from the probe for checking, be sure to replace the metal O-ring. Otherwise, the furnace gas may leak, and then the leaking corrosive gas will cause the built-in heater or thermocouple to go open circuit, or the detector may corrode. (4) Handle the probe with care so that the dust-filter mounted screws on the tip of the probe do not hurt your finger(s). (5) Before opening or closing the terminal box, first remove dust, sand, or the like from the terminal box cover. IM 11M03A02-00E 7-2 <7. INSPECTION AND MAINTENANCE> 7.1 Inspection and Maintenance of the Detector 7.1.1 Cleaning the Calibration Gas Tube The calibration gas, supplied through the calibration gas inlet of the terminal box into the detector, flows through the tube and comes out at the tip of the probe. The tube might become clogged with dust from the measurement gas. If you become aware of clogging, such as when a higher pressure is required to achieve a specified flow rate (600±60 ml/min), clean the calibration gas tube. To clean the tube, follow these steps: (1) Remove the detector from the installation assembly. (2) Following Section 7.1.2, later in this manual, remove the four bolts (and associated spring washers) that tighten the sensor assembly, and the pipe support as well as the U-shaped pipe. (3) Use a rod 2 to 2.5 mm in diameter to clean the calibration gas tube inside the probe. In doing this, keep air flowing from the calibration gas inlet at about 600 ml/min and insert the rod into the tube (3-mm inside diameter). However, be careful not to insert the rod deeper than 40 cm for a general-purpose detector, or 15 cm for a high-temperature detector. (4) Clean the U-shaped pipe. The pipe can be rinsed with water. However, it should be dried out thoroughly before reassembly. (5) Restore all components you removed for cleaning. Follow Section 7.1.2 to restore all components in their original positions. Be sure to replace the O-ring(s) with new ones. Exploded view of components Rod (with outside diameter of ø2 to ø5 mm) Calibration gas tube F7.1E.ai Figure 7.1 Cleaning the Calibration Gas Tube IM 11M03A02-00E  7-3 <7. INSPECTION AND MAINTENANCE> 7.1.2 Replacing the Sensor Assembly The performance of the sensor (cell) deteriorates as its surface becomes soiled during operation. Therefore, you have to replace the sensor when its life expectancy expires, for example, when it can no longer satisfy a zero-gas ratio of 100±30 % or a span-gas ratio of 0±18 %. In addition, the sensor assembly is to be replaced if it becomes damaged and can no longer operate during measurement. If the sensor becomes no longer operable (for example, due to breakage), investigate the cause and remedy the problem as much as possible to prevent recurrence. CAUTION • If the sensor assembly is to be replaced, allow enough time for the detector to cool down from its high temperature. Otherwise, you may get burned. If the cell assembly is to be replaced, be sure to replace the metal O-ring and the contact together. Additionally, even in a case where the cell is not replaced, if the contact becomes deformed and cannot make complete contact with the cell, replace the contact. • If there is any corroded or discolored area in the metal O-ring groove in which the contact is embedded, sand the groove with sandpaper or use a metal brush, and then sand further with a higher grade of sandpaper (no. 1500 or so), or use an appropriate metal brush to eliminate any sharp protrusions on the groove. The contact’s resistance should be minimized. • Use sensor assemblies manufactured in or after Sept. 2000: the serial number on the side of the sensor assembly should be 0J000 or later (for example: OK123, 1AA01 etc) 1. Identifying parts to be replaced In order not to lose or damage disassembled parts, identify the parts to be replaced from among all the parts in the sensor assembly. Normally, replace the sensor, metal O-ring and contact together at the same time. If required, also replace the U-shaped pipe, bolts, filter and associated spring washers. 2. Removal procedures (1) Remove the four bolts and associated washers from the tip of the detector probe. (2) Remove the U-shaped pipe support together with the U-shaped pipe. Remove filter also. (3) Pull the sensor assembly toward you while turning it clockwise. Also, remove the metal O-ring between the assembly and the probe. Remove filter also. (When replacing the assembly, be careful not to scratch or dent the tip of the probe with which the metal O-ring comes in contact (the surface with which the sensor flange also comes in contact). Otherwise, the measurement gas will not be sealed.) (4) Use tweezers to pull the contact out of the groove in the tip of the probe. (5) Clean the sensor assembly, especially the metal O-ring contact surface to remove any contaminants adhering to that part. If you can use any of the parts from among those removed, also clean them up to remove any contaminants adhering to them. (Once the metal O-ring has been used, it can not be reused. So, be sure to replace it.) IM 11M03A02-00E 7-4 <7. INSPECTION AND MAINTENANCE> 3. Part assembly procedure (1) First, install the contact. Being careful not to cause irregularities in the pitch of the coil spirals (i.e., not to bend the coil out of shape), place it in the ringed groove properly so that it forms a solid contact. Groove in which the contact (E7042BS) is placed F7.2E.ai Figure 7.2 Installing the Contact (2) Next, make sure that the O-ring groove on the flange surface of the sensor is clean. Install the metal O-ring in that O-ring groove, and then insert the sensor in the probe while turning it clockwise. After inserting it until the metal O-ring comes in contact with the probe’s O-ring contact surface, properly align the U-shaped-pipe insertion holes with the bolt openings. (3) Attach the U-shaped pipe to its support with filter, then fully insert the U-shaped pipe and its support into the probe. (4) Coat the threads of the four bolts with antiseize grease and then screw them in along with the washers. First, tighten the four bolts uniformly by hand, and then use a torque wrench to tighten all areas of the metal O-ring uniformly, that is, to make sure the sensor flange is perfectly horizontal to the O-ring’s working face in the probe. This is done by tightening first one bolt and then its opposing bolt each 1/8 turn, and then one of the other bolts followed by its opposing bolt, each also 1/8 turn. This continues in rotating fashion until they are all fully tightened with the torque wrench preset to approximately 5.9 N • m. If they are not uniformly tightened, the sensor or heater may be damaged. Replacement of the sensor assembly is now complete. Install the detector and restart operation. Calibrate the instrument before making a measurement. IM 11M03A02-00E  7-5 <7. INSPECTION AND MAINTENANCE> Metal O-ring Sensor U-shaped pipe support Bolts (four) Contact Probe Filter U-shaped pipe Washers (four) 1/8 turn – tighten bolts 1/8 turn (approximately 45°) each F7.3E.ai Figure 7.3 Exploded View of Sensor Assembly CAUTION Optional Inconel bolts have a high coefficient of expansion. If excess torque is applied while the bolts are being tightened, abnormal strain or bolt breakage may result. So, tighten the bolts following the instructions given above. IM 11M03A02-00E 7-6 <7. INSPECTION AND MAINTENANCE> 7.1.3 Stopping and Re-starting Operation When operation is stopped, take care of the followings so that the sensor of the detector cannot become unused. CAUTION When operating an instrument such as boiler or industrial furnace is stopped with the zirconia oxygen analyzer operation, moisture can condensate on the sensor portion and dusts may stick to it. If operation is restarted in this condition, the sensor which is heated up to 750°C firmly fix the dusts on itself. Consequently, the dusts can make the sensor performance very lower. If a large amount of water is condensed, the sensor can be broken and never re-useful. To prevent the above nonconformity, take the following action when stopping operation. (1) If possible, keep on supplying the power to converter and flowing reference air to the sensor. If impossible to do the above, remove the detector. (2) If unavoidably impossible to supply the power and removing the detector, keep on following air at 600ml/min into the calibration gas pipe. When restarting operation, be sure to flow air, for 5-10 minutes, at 600ml/min into the calibration gas pipe before supplying the power to converter. IM 11M03A02-00E Customer Maintenance Parts List Model ZO21DW-L Zirconia Oxygen Analyzer Detector (Pressure balance type) 12 1 10,11 8 5 7 6 4 3 2 9 Item Part No. Qty Description 1 2 3 4 5 E7097BN G7109YC E7042DW E7042BR E7042UD 1 4 4 1 1 Cold Junction Assembly Bolt (M5x12, SUS304 Stainless steel) Washer Plate Cell Assembly 6 7 8 9 E7042AY K9470BJ E7042BS E7042BQ 1 1 1 1 Filter Metal O-Ring Contact Pipe 10 G7011XH G7013XH E7042VR E7042VV G7067XA G7248XA G7007XH 1 1 1 1 1 1 1 Needle Valve (for ZO21DW-L ...-J, -E/SV) Needle Valve (for ZO21DW-L ...-A/SV) Check Valve (for ZO21DW-L ...-J, -E/CV) Check Valve (for ZO21DW-L ...-A/CV) Nipple (for ZO21DW-L ...-J, -E/SV) Nipple (for ZO21DW-L ...-A/SV) Needle Valve 11 12 All Rights Reserved, Copyright © 1992, Yokogawa Electric Corporation. Subject to change without notice. CMPL 11M06B02-01E 6th Edition : Aug. 2009 (KP) Blank Page  Revision Information  Title : In-Situ Type Zirconia Oxygen Analyzer Model ZO21DW Detector User’s Manual  Manual No. : IM 11M03A02-00E Apr. 1989/1st Edition Newly published Aug. 2009/2nd Edition All over revised IM 11M03A02-00E Blank Page User’s Manual In-Situ Type Zirconia Oxygen Analyzer Model ZO21DW Detector Supplement Thank you for selecting our In-Situ Type Zirconia Oxygen Analyzer Model ZO21DW Detector. User's Manual, IM 11M03A02-00E, 2nd Edition, supplied with the product, some revisions/additions have been made. Please replace the corresponding pages in your copy with the attached, revised pages. Revisions: - Page 3-2, - Page 3-.5, - CMPL Section 3.1.1, "Parts Required for Piping in System 1" Table 3.1 Parts required for piping: Change of the description. Section 3.2.1, "Piping Parts for System 2" Table 3.2 Piping parts: Change of the description. "CMPL 11M06B02-01E": Revised to 7th edition. All Rights Reserved, Copyright © 2013, 1st Edition: Apr. 2013 (YK) Subject to change without notice. IM 11M03A02-00E 2nd Edition 3-2 <3. PIPING> CAUTION • The stop valve should be connected directly to the detector. If any piping is present between the detector and the stop valve, water may condense in the pipe, which may cause damage to the sensor by rapid cooling when the calibration gas is introduced. The stop valve should be closed except while the calibration gas is being introduced. • The reference gas should have an oxygen concentration identical to that of fresh air (21%). 3.1.1 Parts Required for Piping in System 1 Check that the parts listed in Table 3.1 are ready. Table 3.1 Parts required for piping Piping section At the calibration gas inlet At the reference gas inlet Parts required Description Stop valve Recommended by YOKOGAWA (L9852CB or G7016XH) * Nipple R1/4 or 1/4 NPT On the open market Tube connecting joint R1/4 or 1/4 NPT – ∅6  ∅4 mm soft tube On the open market Air set Recommended by YOKOGAWA (K9473XH/K9473XJ) Piping joint R1/4 or 1/4 NPT On the open market Note : The parts with an asterisk (*) may not be required. 3.1.2 Connection to the Calibration Gas Inlet When carrying out calibration, connect the piping (∅6  ∅4 mm tube) from the standard gas unit to the calibration gas inlet of the detector. First, mount a stop valve (of a quality specified by YOKOGAWA) on a nipple (found on the open market) as illustrated in Figure 3.2, and mount a joint (also found on the open market) at the stop valve tip. (The stop valve may be mounted on the detector prior to shipping the detector.) Note 1: Mount the stop valve close to the detector. Stop valve Nipple Tube connection joint F4.2E.EPS Figure 3.2 Connection to the calibration gas inlet IM 11M03A02-00E 3-5 <3. PIPING> 3.2.1 Piping Parts for System 2 Check that the parts listed in Table 3.2 are ready. Table 3.2 Piping parts Piping section Calibration gas piping At the reference gas inlet Parts required Description Stop valve or Check valve Recommended by YOKOGAWA (L9852CB or G7016XH for Stop valve, E7042VR or E7042VV for Check valve) * Nipple R1/4 or 1/4 NPT Zero gas cylinder Recommended by YOKOGAWA (G7001ZC) Regulator valve Recommended by YOKOGAWA (G7013XF or G7014XF) Piping joint R1/4 or 1/4 NPT Air set Recommended by YOKOGAWA (K9473XH/K9473XJ) Piping joint R1/4 or 1/4 NPT On the open market On the open market On the open market Note : The parts with an asterisk (*) may not be required. 3.2.2 Piping for the Calibration Gas This piping is to be installed between the zero gas cylinder and the ZA8F flow setting unit, and between the ZA8F flow setting unit and the ZO21DW detector. The cylinder should be placed in a calibration gas unit case or the like to avoid any direct sunlight or radiant heat so that the gas cylinder temperature does not exceed 40°C. Mount a regulator valve (specified by YOKOGAWA) on the cylinder. Mount a check valve or stop valve (specified by YOKOGAWA) on the nipple (found on the open market) at the calibration gas inlet of the detector as illustrated in Figure 3.4. (The check valve or the stop valve may have been mounted on the detector when shipped.) Connect the flow setting unit and the detector to a stainless steel pipe ø6  ø4 mm (or nominal size 1/4 inch). Stop valve or Check valve Piping for the Calibration gas, ø6 × ø4 mm Stainless steel pipe Piping for the Reference gas, ø6 × ø4 mm Stainless steel pipe F4.8E.EPS Figure 3.4 Check the valve connection to the calibration gas inlet IM 11M03A02-00E Customer Maintenance Parts List Model ZO21DW-L Zirconia Oxygen Analyzer Detector (with Flameproof Terminal Box) 12 1 10,11 8 5 7 6 4 3 2 9 Item Part No. Qty Description 1 2 3 4 5 E7097BN G7109YC E7042DW E7042BR E7042UD 1 4 4 1 1 Cold Junction Assembly Bolt (M5x12, SUS304 Stainless steel) Washer Plate Cell Assembly 6 7 8 9 E7042AY K9470BJ E7042BS E7042BQ 1 1 1 1 Filter Metal O-Ring Contact Pipe 10 G7011XH G7013XH E7042VR E7042VV G7067XA G7248XA G7007XH 1 1 1 1 1 1 1 Stop Valve (for ZO21DW-L ...-J, -E/SV) Stop Valve (for ZO21DW-L ...-A/SV) Check Valve (for ZO21DW-L ...-J, -E/CV) Check Valve (for ZO21DW-L ...-A/CV) Nipple (for ZO21DW-L ...-J, -E/SV) Nipple (for ZO21DW-L ...-A/SV) Needle Valve 11 12 All Rights Reserved, Copyright © 1989, Yokogawa Electric Corporation. Subject to change without notice. CMPL 11M06B02-01E 1st Edition : Apr. 1989 (YK) 7th Edition : Apr. 2013 (YK)