OPERATING AND MAINTENANCE MANUAL

Transcription

1 Series 4300 Engineered Performance

2 TABLE OF CONTENTS 0 INTRODUCTION 1 1 Scope 1 2 Description 1 3 Specifications 1 0 INSTALLATION 1 1 Mounting 1 2 Piping 1 1 Connecting Process Pressure 2 2 Vent Connections 2 3 Supply Pressure OPERATION Adjustment Proportional Band Differential Gap Set Point Low Pressure Cutout High Pressure Cutout Start-up Procedure MAINTENANCE Changing Controller Action Bourdon Tube Replacement TROUBLE SHOOTING PARTS LIST , August, 2012

3 0 INTRODUCTION 1 Scope This manual provides information on installation, operation and maintenance for the Norriseal Series 4300 Pressure Controllers. 2 Description The Norriseal Series 4300 Pressure Controller is a pneumatic pressure controller that uses a bourdon tube sensing element. The output signal may be either proportional or on/off. 3 Specifications Controller Action: Direct (increasing process pressure increases output), or reverse (Increasing process pressure decreases output. Control Modes: Proportional control with continuous bleed, or ON-OFF control with intermittent bleed. Sensing Element: Bourdon tube (For pressure ranges, see Table 1). Input Signal: Positive pressure consistent with Bourdon tube rating. Output Signal: Proportional: 3-15 psig or 6-30 psig ON-OFF: 0-20 psig or 0-35 psig Supply Pressure Medium: Clean dry air or noncorrosive gas Recommended Supply Pressure: 20 psig for 3-15 output 35 psig for 6-30 output Air Consumption: Orifice Size 20 psig supply 35 psig supply Small 15 SCFH 20 SCFH Large 35 SCFH 20 SCFH Controller Adjustment: Set Point: Continuously adjustable WARNING! The bourdon tube may be damaged if the process pressure exceeds the tube rating. Also, if a flammable medium is present in the process or supply pressure lines then a danger of personal injury and equipment damage exists if an over pressure condition occurs. Thereto set proportional band anywhere within Bourdon tube range. Proportional Band: 2% to 50% of Bourdon tube range. Recommended Differential Gap: For 20 pisg Supply: 10% to 25% of Bourdon tube range For 35 pisg Supply: 15% to 25% of Bourdon tube range Temperature Limits: -40 to 150 F (Ambient and Process) Mounting Options: May be mounted on actuator yoke or diaphragm housing. Weight: Approximately 8.6 lbs. Materials of Construction See parts list CAUTION! Before disassembly or maintenance, all pressures in this device must be relieved. Failure to relieve pressures may result in personal injury or device damage. The resulting uncontrolled venting or spilling of the line fluids may cause personal injury, loss of process control or environmental contamination. Figure 1 0 INSTALLATION 1 Mounting Make sure it is mounted vertically with the pressure gauges nearest to the top. The following instructions for mounting apply to field mounting of controllers not shipped as part of a control valve assembly. Controllers can be mounted on the actuator yoke, the diaphragm housing or the pipe. 2 Inspection Refer to Figure 2 for piping connections. Supply, output and process connections are 1/4 NPT female. The vent the connection, located in the bottom of the case, is 1/4 NPT female , August, 2012 Page 1 of 8

4 fore, suitable pressure relief devices should be installed in the process and supply pressure lines. 1 Connecting Process Pressure Process pressure connection is located in the side of the control pressure block at the rear of the case. (refer to Figure 2) Good piping practices should be followed when installing shutoff valves, vents, drains or seal systems as needed in the process pressure lines. To prevent trapping unwanted gas or liquid in the bourdon tube, the process pressure line should slope upward toward the controller for gas systems and downward toward the controller for liquid systems. The slope should be approximately 1 inch per foot. The process pressure line should be connected in a straight section of pipe approximately 10 pipe diameters from the control valve, and away from pipe bends or elbows and areas of unusually high fluid velocity. The process pressure line must be connected downstream of the control valve for pressure reducing service and upstream for pressure relief service. A needle valve installed in the process pressure line will protect the controller from sudden pressure pulsations. 2 Vent Connections The vent connection, located in the bottom of the controller case, must not be allowed to become plugged by foreign matter. Check the vent periodically to be sure it is not plugged. WARNING! Figure 2 If the controller is in an enclosed area and the flammable gas is used as the supply pressure medium, there is a danger of fire and explosion from accumulation of vented gas. To avoid personal injury and equipment damage, a vent line must be connected to the controller vent connection to carry venting gas to a safe area. 3 Supply Pressure The supply pressure medium must be clean, dry air or noncorrosive gas. Use a suitable regulator to reduce the source pressure to 20 psig for 3-15 psig output, or 35 psig for 6-30 psig output. CAUTION! If these values of supply pressure are exceeded, it is possible to lose control of the pressure stability. 3.0 OPERATION 3.1 Adjustment Required adjustments depend on controller configuration. When adjustments are made, set the proportional band or differential gap before making other adjustments. 3.1 Proportional Band To adjust the proportional band, loosen the knob located in the center slot of the proportional band adjusting plate. Slide the knob to the desired setting and retighten. 3.2 Differential Gap To adjust the differential gap of two-position (on/off) controllers, turn the adjusting screw clockwise for a wide gap and counterclockwise for a narrower gap. 3.3 Set Point To adjust the set point pressure, turn the knob on the pressure adjustment assembly. Turn the knob clockwise to increase the set point and counterclockwise to decrease it. 3.4 Low Pressure Cutout To adjust the low pressure cutout, turn the stop screw (refer to Figure 3). Increase the Figure 3 Page 2 of , August, 2012

5 cutout pressure by moving the stop screw closer to the flapper. Decrease the cutout pressure by moving the stop screw away from the flapper. 3.5 High Pressure Cutout On controllers equipped with high pressure cutout, turn the set point adjustment knob clockwise to increase the pressure at which the cutout occurs and counterclockwise to decrease the pressure. 3.2 Start-up Procedure Open the needle valve in the process pressure line Apply supply pressure to the controller. The supply pressure gauge should read 20 psig for 3-15 output, or 35 for 6-30 output. Adjust the regulator if you need to adjust the supply pressure. On the proportional controller, set the proportional band at 20 percent. On a two-position (on/off) controller, adjust the set point until the reading on the output pressure gauge suddenly increases. On a proportional controller, adjust the set point until the output pressure gauge reads as follows: a. (output) 3-15 psig = (gauge reading) 9 psig b. (output) 6-30 psig = (gauge reading) 18 psig Slowly open the upstream and downstream isolating valves, and close the bypass valve. 8. Figure 4 If the controller output pressure oscillates, partially close the needle valve in the process pressure line. If oscillation continues, adjust the proportional band to a higher setting. Adjust the set point pressure to the desired value. 4.0 MAINTENANCE WARNING! The following procedures require the controller to be taken out of service. To avoid the possibility of personal injury and equipment damage, make sure all pressure is vented from the process pressure line before disconnecting any fittings. 4.1 Changing Controller Action Refer to Figure 4 while following these steps: Disconnect and remove the supply and output pressure tubing (1 and 2) from the orifice block (3) and manifold (4). Loosen the three machine screws (5) holding the proportional band plate (6) and remove it with the sliding block assembly (7). Unhook the flapper spring (8) from the flapper (9). Unscrew the spring anchor (10) and machine screw (11). The spring may remain attached to the spring anchor. Transfer the orifice block (3) to the opposite side of the flapper (9). Install the machine screw (11) in the top hole and the spring anchor (10) in the bottom hole. Tighten both. Reconnect the spring to the flapper , August, 2012 Page 3 of 8

6 Loosen the knob (12) that holds the sliding block (7) in the center slot of the proportional band plate (6). Turn the sliding block (along with the pivot pin) 180. Reinstall it in the slot and tighten the knob. Reinstall the proportional band plate (6) while making sure that the pivot pin is on the same side of the flapper (9) as the orifice block (3). When properly positioned, the spring will pull the flapper against the pin. Reinstall the supply and output pressure tubing (1 and 2). The longer tubing section goes in the supply, the shorter section goes in the output. Refer to 3.2 Start Up Procedure to place the controller back in service. 4.2 Bourdon Tube Replacement CAUTION! Be sure that the process pressure is completely vented before starting this procedure. Refer to Figure 4 while following these steps: Disconnect the supply and output pressure tubing (1 and 2) from the orifice block (3) and manifold (4). Loosen three machine screws (5) and remove the proportional band plate (6). Unhook the flapper spring (8) from the flapper (9). Unscrew the tubing nut (13) from the fitting on the bourdon tube socket. Remove the two machine screws (14) securing the bourdon tube (15) to the mounting plate (16) and remove the bourdon tube (with flapper) from the case. Loosen the flapper pivot screws (17) and remove the flapper from the bourdon tube. Connect the flapper to the replacement bourdon tube. NOTE: Do not over-tighten the flapper pivot screws. When properly adjusted, the screws will allow the flapper to pivot freely but will prevent excessive end play. 8. Install, but do not tighten, the machine screws (14) that secure the bourdon tube to the mounting plate (16). 9. Reconnect, but do not tighten, the tubing nut (13) to the bourdon tube. NOTE: Be sure that threads are properly engaged. 10. Tighten the machine screws (14) to secure the bourdon tube to the mounting plate. 1 Tighten the tubing nut (13). 1 Connect the spring to the flapper. 13. Reinstall the proportional band plate (6) with the pivot pin on the same side of the flapper as the orifice block. The spring will pull the flapper against the pin. 14. Reconnect the supply and output pressure tubing (1 and 2) to the orifice block (3) and the manifold (4). 15. Refer to 3.2 Start Up Procedure to place the controller back in service. Page 4 of , August, 2012

7 5.0 TROUBLE SHOOTING Table 1 Trouble Shooting Symptom Probable Cause(s) Corrective Action(s) You are unable to achieve a full pressure reading on the output pressure gauge. The output pressure gauge may be defective. Replace the gauge if it is defective. The output pressure oscillates (called cycling or hunting ) There are leaks in the output pressure tubing or fittings. The nozzle may be obstructed by foreign matter. If it is equipped with a low-pressure cutout, the stop screw may be too close to the flapper. The flapper may not be perpendicular to the nozzle. The proportional band setting may be too low. The control valve plug or the stem may be sticking Check the fittings for leaks and tighten them if they are loose. Remove the nozzle from the orifice block and inspect it. Remove the obstruction if necessary. Replace the nozzle. Adjust the stop screw away from the flapper. Examine the position of the flapper relative to the nozzle. This may require the removal of the proportional band adjustment plate. Adjust the proportional band to a higher setting. Check the operation of the control valve, independent of the controller , August, 2012 Page 5 of 8

8 6.0 PARTS LIST Page 6 of , August, 2012

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12 H E A D Q U A R T E R S, M A N U F A C T U R I N G P L A N T A N D S A L E S West Little York Houston, Texas T: (713) F: (713) Due to the continuous improvement at Norriseal, specifications and/or prices are subject to change without notice or obligation.