Operation - Maintenance L-Head For dispensing controlled ratio shots of resin and isocyanate. 3000 psi (20.6 MPa, 206 bar) Maximum Working Pressure Important Safety Instructions Read all warnings and instructions in this manual. Save these instructions. See page 2 for model information.
Models Contents Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Isocyanate Hazard . . . . . . . . . . . . . . . . . . . . . . . . . . Material Self-ignition . . . . . . . . . . . . . . . . . . . . . . . . Moisture Sensitivity of Isocyanates . . . . . . . . . . . . Keep Components A and B Separate . . . . . . . . . . Foam Resins with 245 fa Blowing Agents . . . . . . . Changing Materials . . . . . . . . .
Warnings Warnings The following warnings are for the setup, use, grounding, maintenance, and repair of this equipment. The exclamation point symbol alerts you to a general warning and the hazard symbol refers to procedure-specific risk. Refer back to these warnings. Additional, product-specific warnings may be found throughout the body of this manual where applicable.
Warnings WARNING EQUIPMENT MISUSE HAZARD Misuse can cause death or serious injury. • Do not operate the unit when fatigued or under the influence of drugs or alcohol. • Do not exceed the maximum working pressure or temperature rating of the lowest rated system component. See Technical Data in all equipment manuals. • Use fluids and solvents that are compatible with equipment wetted parts. See Technical Data in all equipment manuals. Read fluid and solvent manufacturer’s warnings.
Isocyanate Hazard Isocyanate Hazard Spraying materials containing isocyanates creates potentially harmful mists, vapors, and atomized particulates. • Keep the ISO lube pump reservoir filled with Graco Throat Seal Liquid (TSL), Part 206995. The lubricant creates a barrier between the ISO and the atmosphere. • Use moisture-proof hoses specifically designed for ISO, such as those supplied with your system. • Never use reclaimed solvents, which may contain moisture.
Component Identification Component Identification A Q B C D H P G E F J N K L M FIG.
Installation Installation When hoisting the MixHead from an overhead position, always lift by the top eyebolt. Handle the MixHead with care. The internal moving parts are precisely machined for proper alignment. Any disturbance of this alignment may result in MixHead failure. Hydraulic & Chemical Hose Installation Install Hydraulic Hose The fittings are identified on the MixHead body and the hoses are color-coded to aid in identification and proper installation.
Installation 5. Manually cycle the material plunger back and forth to check for proper operation. Check for hydraulic leaks and retighten fittings as required. Make sure the proximity switch is securely tightened and making contact, and then return the material plunger to the closed/recirculation position. NOTICE Before connecting the chemical hoses, make sure the hydraulic hoses are properly connected and the cleanout plunger and material plunger have been tested for proper operation.
Maintenance Maintenance All maintenance must be done with pressure relieved and the power switched off and locked out, unless otherwise noted.
Maintenance Nozzle Grip Assembly Removal and Cleaning The nozzle grip assembly must be removed, disassembled and cleaned whenever disconnecting the chemical hoses, replacing the internal o-rings, and/or changing the injection nozzle and adjustment stem. It is advisable to maintain a supply of spare nozzle grips, adjustment stems, hex o-ring seats, locknuts, and the necessary screws and o-rings. Tools Required See Additional Tools and Accessories on page 29. • Nozzle ejector • 5/32 in.
Maintenance 4. Using a clockwise twisting motion, pull the entire nozzle grip assembly out of the MixHead body. 5. If the injection nozzle will not come out with the nozzle grip assembly, use the nozzle ejector tool to remove the injection nozzle. See Additional Tools and Accessories on page 29. Nozzle Grip Cleaning 6. Flush remaining chemical and dirt from the nozzle grip bore and mating surface of the MixHead body. 7. Disassemble the nozzle grip assembly and soak the metal parts in solvent. 8.
Maintenance Cleanout Plunger Proximity Switch Replacement • • Do not operate the MixHead unless all proximity switches are in place and the proximity switch alarm is operational and armed. A shock hazard or unpredictable machine operation could occur if the proximity switch is separated from its mating cord set, or if either the proximity switch or its mating cord set are used with a different switch or cord set.
Maintenance Proximity Switch Replacement See FIG. 3 on page 12. 1. Turn OFF the hydraulic fluid motor, bleed the hydraulic pressure to zero and allow the fluid to cool. 2. Disconnect the cord set (BA) from the machine at the Amphenol connector (BB). 3. Unscrew the knurled knob at the end of the cord set (BA) and disconnect the cord set from the proximity switch (BC) on the MixHead. 4. Unscrew the proximity switch (BC) from the MixHead using the open-end wrench. 5.
Maintenance Material Plunger Proximity Switch Replacement 6. Insert the sensor gauge (CF, DG) into the material plunger housing/sensor cap. 7. Install the replacement proximity switch into the appropriate threaded hole in the material plunger housing/sensor cap as follows. Do not operate the MixHead unless all proximity switches are in place and the proximity switch alarm is operative and armed. Tools Required • M2.
Maintenance c. e. This step will ensure a clearance of 0.010-0.015 in. (0.254-0.381 mm) between the material plunger (DF) and proximity switch (DA). While holding the conduit (DB) stationary, tighten the adapter (DC) by hand until it contacts the jam nut (DD). d. Remove the sensor gauge (DG) from the sensor cap (DH). 8. Reinstall the cover plate to the material plunger housing/sensor cap using the two M4 flat head screws. 9. Connect the proximity switch to the machine at the Amphenol connector.
Maintenance DF DA 1 DE DC DB DG DH DD 1 0.010-0.015 in. (0.254-0.381 mm) FIG. 5: Material Proximity Switch - Models 13/20 and 16/25.
Maintenance Cleanout Plunger Stroke Adjustment The cleanout plunger stroke is properly set during factory assembly so that the cleanout plunger completely clears the impingement chamber during a pour. Usually, no adjustment is needed. However, for some applications where the chemical flow is on the lower end of the MixHead flow range, improved mixing may be achieved by adjusting the cleanout plunger so that it partially blocks the impingement chamber leading into the exiting chamber.
Maintenance 4. Place the steel rod between the two tie rods on top of the adjusting plug and carefully turn the adjusting plug clockwise to a desired position within the range listed above. One complete turn moves the adjusting plug 0.078 in. (1.9812 mm). 5. Lock the adjusting plug into position by tightening the shaft nut against the cylinder housing with a hook spanner. 6. Purge all air from the hydraulic fittings. See step 3 on page 7.
Maintenance Pour Nozzle Maintenance Cleanout Plunger Retract Routine During operation, periodic lubrication with mesamoll may be all that is required to prevent sticking. However, in cases where sticking is a continual problem, the cleanout plunger retract routine may be utilized. With proper maintenance, the L-Head is capable of performing thousands of pours without the need for removing and cleaning the pour nozzle.
Maintenance Pour Nozzle Removal and Installation Step Seal and Scraper Seal Replacement NOTICE Do not attempt to replace the step seal and/or scraper seal yourself. Tools Required • Torque wrench with M6 and M8 sockets • Fine-grade wire brushes on air tool 1. Cycle the cleanout plunger to the open/pour position.
Troubleshooting Troubleshooting Any individual working with the equipment must be knowledgeable in the necessary safety procedures. Unless otherwise noted, all electrical troubleshooting must be done with the incoming power switched off and locked out at the source.
Troubleshooting Symptom Probable Cause(s) Corrective Actions Reference Hydraulic leak around Damaged o-ring Cleanout Plunger Proximity Proximity Switch not tightSwitch ened down onto Adjusting plug Replace o-ring See page 12 Tighten Proximity Switch against Adjusting Plug to compress seal See page 12 Hydraulic leak out of sens- Improper sealing ing area of Material Plunger Replace with Polypak seal and modify Sensor Cap Chemical leak out of Nozzle Grip Assembly Loose Hex o-ring Seat Replace o-
Troubleshooting 312753E 23
Parts Parts Models 5/8, 6/10, 10/14 11 10 16 1 3 18 17 2 7 9 15 4 8 13 5 14 6 12 24 312753E
Parts Parts List Ref. 1 2*† 3*† 4*† 5 6 7 8 Part No. 0135-910 ------M0450 M0454-2 M362-3 --------9 M1051-1 10 M24017 11 M24022 12 MA1009 13 MA1755 14 MA1759 15 MA1769 16 MS4086 17† --18† --* Description Qty O-RING 1 O-RING 1 O-RING 1 O-RING 1 SEAT, hex o-ring 1 LOCKNUT 1 COVER, sensor 1 1 NOZZLE, pour (20.20.5/8) 1 NOZZLE, pour (20.20.6/10) 1 NOZZLE, pour (20.20A.6/10) 1 NOZZLE, pour (20.20.
Parts Models 13/20 and 16/25 111 110 116 101 103 118 117 102 109 104 108 115 107 113 105 106 114 112 26 312753E
Parts Parts List Ref 101 102*† 103*† 104*† 105 106 107 108 Part No.
Parts Orifice Kits Orifice Selection This section is provided to give an approximate orifice size needed for a given application. There is no guarantee that this formula will give you the correct orifice. EB EC EA ED EE To help choose the correct orifice for your application, use the following equation to find a suggested ‘effective’ orifice size. Key: EA EB EC ED EE L-injection Nozzle L-style Injection Needle O-ring O-ring, fluoroelastomer O-ring, fluoroelastomer FIG.
Parts Additional Tools and Accessories Part No. MU1079 M1978-1* MU1140† MU1063* MU1080† MU1064*† MU1066*† MU1069*† MU1154*† MU1155*† MU1067† Description EJECTOR, nozzle GAUGE, sensor (5/8, 6/10, 10/14) GAUGE, sensor (13/20, 16/25) WRENCH, hook spanner (5/8, 6/10, 10/14) WRENCH, hook spanner (13/20, 16/25)) HEX L-KEY, 3 mm, long arm HEX L-KEY, 6mm, long arm HEX KEY, 5/32 in., 6 in. HEX L-KEY, 3/8 in., long arm WRENCH, open end, 1 in.
Parts 30 312753E
Technical Data Technical Data Proximity Switch Electrical Requirements . . . . Cleanout Piston: 50 mA @24VDC Material Piston: 60 mA @ 16 VDC Fittings (See FIG. 1 on page 6). . . . . . . . . . . . .
Graco Standard Warranty Graco warrants all equipment referenced in this document which is manufactured by Graco and bearing its name to be free from defects in material and workmanship on the date of sale to the original purchaser for use. With the exception of any special, extended, or limited warranty published by Graco, Graco will, for a period of twelve months from the date of sale, repair or replace any part of the equipment determined by Graco to be defective.
