Installation, Operating,
and Maintenance
Instructions Parts List
12501 Telecom Drive, Tampa Florida 33637
10/9.5.1.2
Rev. 2
CONTROL VALVES |
|
Low Pressure, Single Ported, Cage Trim |
|
Classes DLO-2, DDLO-2 125# & 250# Cast Iron |
|
Classes DLOS-2 & DDLOS-2 150# & 300# Cast Steel |
|
Classes DLOS-2 & DDLOS-2 150# & 300# Stainless Steel |
|
TABLE OF CONTENTS |
|
SECTION I – INSTALLATION .................................................................................................................... |
2 |
SECTION II – OPERATION ......................................................................................................................... |
2 |
SECTION III – MAINTENANCE ................................................................................................................. |
3 |
SECTION IV – PARTS LIST....................................................................................................................... |
10 |
ILLUSTRATION INDEX
DRAWINGS, DIMENSIONS, TYPICAL INSTALLATIONS AND
MISCELLANEOUS DATA
Figure 1 - Typical Installation Expand as required for fluid flow………………………………………………2 Figure 2 - Typical Control Valve Station for Control of Compressible Fluids at 25% or Less of Inlet Pressure.
Expand further as required for fluid flow………………………………………………………………….2 Figure 3 - Typical Valve Cutaway………………………………………………………………………………3 Figure 4 - Installation Sequence…………………………………………………………………………………4 Figure 5 - Installation Sequence…………………………………………………………………………………4 Figure 6 - Installation Sequence…………………………………………………………………………………5 Drawing - Diaphragm Control Valve…………………………………………………………………………..11 Drawing - Accessory Mount View……………………………………………………………………………..12 Drawing - Diaphragm Control Valve CLASS D(D)LOS-2, D(D)LOAS-2 and CLASS
D(D)LO-2, D(D)LOA-2……………………………………………………………………………14 Drawing - Direct Acting……………………………………………………………………………………….17 Drawing - Reverse Acting……………………………………………………………………………………..18
1
SECTION I – INSTALLATION
1. VALVE POSITION
Install control valve in the highest horizontal line of piping in an accessible location and with arrow on side of valve body in direction of fluid flow. Control valve may be placed in any position, but upright is preferable for ease of maintenance.
Figure 1 - Typical Installation Expand as required for fluid flow
CAUTION!
The piping system must be adequately designed and supported to prevent extraordinary loads to the pressure
Expand outlet pipe to twice control valve inlet pipe size. Use tapered expander.
∙Connect control pipe for control pilot ahead of outlet stop valve and at least 2’ to 3’ downstream from end of expander.
∙Make control pipe connection at least 18” to 2’ from outlet stop valve, any elbow or other flow direction changing fitting.
2. PROBLEM PREVENTING PROCEDURES
∙Provide removal space above, below and around control valve for easy removal of parts during maintenance. See Dwg. 10/9.4.1 or 10/9.4.3 for dimensions.
∙Blow or flush out pipelines thoroughly before installing control valve.
∙Protect control valve and following equipment with a SELF-CLEANING STRAINER.
∙Install stop valves and gauges in inlet and outlet lines to provide means for checking adjustment and operation of equipment.
∙Provide proper inlet and outlet drainage in steam service to prevent water hammer or possible erosion in equipment.
∙Adhere to good piping practice. Install a bypass around the control valve.
3. Connect operating medium tubing from control pilot, instrument or loading device to diaphragm chamber connection of control valve or to valve positioner, if one is in use. Maximum allowable operating pressure for diaphragm actuators is 60 psig.
4. Recommended Piping for Control of Compressible Fluids at Values of 25% or Less of Inlet Pressure.
2
Figure 2 - Typical Control Valve Station for Control of Compressible Fluids at 25% or Less of Inlet Pressure. Expand further as required for fluid flow.
NOTE: Where sensing impulse is taken 2’ to 3’ downstream from control valve (expander), dimension “A” minimum of 6’ to 10’ will provide lowest noise and velocity factors, accurate pressure sensing and reasonable bypass length.
SECTION II – OPERATION
1. Close inlet and outlet stop valves.
2. Check that control valve responds properly through rated travel in relation to changes in operating pressure on the diaphragm. Rated travel is shown by position of travel indicator on valve stem relative to travel indicator scale on yoke.
3. Manually operate control valves fitted with manual operating devices through rated travel to check freedom of movement. Return manual operating device to its standby position.
4. Place control valve in operation in accordance with instructions furnished with control pilot or operating device.
Figure 3 - Typical Valve Cutaway
3
SECTION III –
MAINTENANCE
To reduce maintenance time refer to proper drawing and follow steps shown below for applicable operation.
RENEWING VALVE PLUG STEM PACKING
(See Fig. 3, Fig. 4 and 5)
Renew valve plug stem packing if control valve has been in service beyond normal maintenance and packing shows signs of wear. Wear will be indicated by leakage at the packing gland. Minor leakage of graphite packing can be corrected by tightening the packing flange.
CAUTION!
Over-tightening of the packing flange adjustments can cause erratic operation of the valve.
Where LESLIE (BRAIDED TEFLON GRAPHITE) packing is in use, additional packing rings can be installed to overcome minor leakage without dismantling the control valve or breaking valve plug connection.
Shut down inlet and outlet stop valves and check that valve body is not under pressure. Remove nuts and lift packing flange and packing bearing a sufficient height on valve plug stem to apply a split packing ring around diameter of valve plug stem. Lower packing bearing over the new ring, lower packing flange and tighten sufficiently with nuts to stop leakage.
To replace LESLIE “TEFLON” packing set or a complete GRAPHITE 11 packing set, the control valve must be dismantled.
Installation of Stem Packing
Stuffing box interior and valve plug stem must be clean, smooth and free from imperfections that may cause new packing to leak.
4
BRAIDED PTFE/GRAPHITE TYPE PACKING
Figure 4 - Installation Sequence
1. Place metal ring in stuffing box making sure it bottoms in box followed by spring and second metal ring. Install bottom Teflon adaptor chevron, four Teflon packing chevrons and top Teflon adaptor chevron in accordance with Fig. 6.
2. Install packing follower, packing flange and nuts. Tighten stuffing box nuts until follower bottoms on bonnet.
PTFE CHEVRON TYPE PACKING
Figure 5 - Installation Sequence
LAMINATED GRAPHITE PACKING
Packing tools are available from Leslie Controls and should be used to insure proper installation of packing. Packing tool reference numbers are shown on Dwg. 10/0.5.9, which also shows how to make the tools.
Figure 6 - Installation Sequence
INSTALLATION
Place spacers and packing rings over stem and into packing box in order shown on drawing, one at a time, seating each firmly and using care not to tear rings on the stem threads. Adjust packing gland nuts equally-finger tight plus 1/6 turn (one flat of nut).
ADJUSTMENT
During start-up some leakage may be observed. Do not readjust packing-allow at least 15 minutes for pressure/temperature stabilization to occur. If leakage continues adjust a maximum of 1/6 turn at a time. If pressure is raised considerably, the packing may leak slightly. Do not readjust-leakage will stop when new pressure/temperature stabilization is reached.
BREAK-IN
For best results it is recommended that after packing installation and adjustment the valve be fully stroked approximately 20 times to break-in the packing and reduce stem friction.
5
WARNING
Injury or death can occur due to failure to completely isolate valve from all sources of pressure before beginning disassembly. Do not proceed until valve has been completely isolated from the process and vented to atmosphere.
DISASSEMBLY OF ACTUATOR FROM VALVE BODY ASSEMBLY
(See Fig. 6, 6A, 7 and 9 in Appendix)
1. Close inlet and outlet stop valve and relieve all pressure from piping involved. Remove all compression from adjusting spring(s).
2. NORMALLY OPEN VALVES-DLO(S)-2. Relieve air pressure from diaphragm of actuator. Remove the tubing from upper diaphragm case.
3. NORMALLY CLOSED VALVES- DDLO(S)-2. Supply sufficient air to the actuator diaphragm to keep valve plug from touching seat while disengaging valve plug stem from actuator stem.
4. Loosen valve stem nut. Use wrench on plug stem flats and turn valve plug out of actuator stem until stems separate. Remove the tubing from lower diaphragm case.
5. Remove cap screws holding actuator to bonnet and lift off actuator.
DISASSEMBLY VALVE BODY SUBASSEMBLY (VBSA)
(See Fig. 6 and 6A in Appendix)
1. Remove actuator from VBSA as previously described in Disassembly of Actuator from Valve Body Subassembly.
2. Remove bonnet nuts (10). Also bolts (11) for DLOS only.
3. Lift bonnet assembly including valve plug
(2)from valve body (1).
4.Remove valve plug (2), packing bearing
(12)and old packing set (17). Include spring (15) for Teflon packing set.
5. Remove bonnet gasket (8), seat retainer (5), seat ring (4) and seal (3). If necessary, remove seat ring by forcing a wooden dowel into seat bore and lifting.
CLEANING
1. Clean all parts thoroughly. Polish valve plug stem with crocus cloth. It should be smooth and free of scratches in packing area. Use approved, non-residue forming solvent for cleaning. Wipe dry with clean cloth.
2. Inspect all parts and replace any excessively worn or damaged part.
3. Install a new packing set of braided Teflon graphite or Teflon chevron rings as shown on packing installation sketch Fig. 3, 4 or 5. See previous section on renewing valve plug stem packing.
4. The packing bearings have a long wearing life material which under normal usage should not require replacement, however, if damaged or worn the packing bearing (12) and/or the bonnet (6) must be replaced. (Lower bearing in bonnet is not supplied separately.)
5. The gasket (8) and seal (3) should be replaced each time the valve body subassembly is disassembled for cleaning.
All LESLIE control valves are made of the finest material obtainable, time-tested and backed by over seventy-five years of know-how. Machining is done by expert craftsmen and each valve is inspected and service tested before shipment to you.
REASSEMBLY VALVE BODY SUBASSEMBLY LAPPING VALVE PLUG AND SEAT
1. Insert raised face of seat ring (4) into seat retainer cage (5) and place these into bore of valve body bridge.
2. Place new bonnet gasket (8) into body recess.
6
3. With light pressure and turning motion assemble valve plug (2) to the bonnet (6) being careful not to damage bearings or packing set (17).
4. Apply very thin film of superfine lapping compound to the valve plug seating surface.
5. Assemble bonnet (6) complete with valve plug (2) to valve body (1) applying nuts (10) only finger tight to studs or bolts (11). The bonnet acts as a guide when grinding valve plug.
6. Use wrench on flats of valve plug stem for turning valve plug (2). Do not bear down on valve plug stem when lapping. Weight of parts is sufficient to cause lapping action.
7. As lapping progresses lift valve plug off seat occasionally and rotate 45˚ to keep compound evenly distributed. Remove all traces of compound after lapping. Excessive lapping should be avoided.
8. Remove bonnet nuts (10), bonnet assembly, and all body assembly parts. Then remove all traces of lapping compound from both valve plug (2) and seat ring (4). Check that a fine continuous ring of contact has been made on both seats. The contact ring should be visible but without depth.
9. Apply silicone grease to seat ring seal (3) and insert seal into groove of seat ring (4).
10.Insert raised face of seat ring (4) into seat retainer cage (5) and place these into bore of valve body bridge. Seat ring (4) sealing face must be firmly seated in place.
11.Place the bonnet gasket (8) in body recess and add the bonnet assembly. Apply nuts (10) to bolts or studs (11) and tighten evenly for metal to metal joint.
12.Place actuator back on bonnet. CAUTION:
For reverse acting actuators only, air pressure must be supplied to the diaphragm chamber sufficient to cause actuator stem to lift its full travel so valve plug threads may later be engaged.
13.Place packing flange (13) with concaved side of hole facing down thru window of
Loading...