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2013FallShotcreteEMag

Nozzleman Knowledge material hoses carpenter’s hammer rather than a sledge- Be sure to only use a material hose designed hammer, as you are only trying to loosen dry for dry-mix to ensure performance and allow for material by vibrating it—you do not want to predictability in terms of wear. Before every use, damage the structure of the hose; inspect all material hoses, air hoses, and water • Loosen up material from the nozzle end toward hoses for cracking, abrasions, or excessive wear, the gun. If you work the opposite way, you and replace hoses if necessary. Hose fatigue will may just be allowing more material to get vary with the type of material being used. Squeeze behind the plug and add to it; and bend hoses to determine if they have become • As you loosen up material, work to shake the too thin or can be bent too easily. If you notice a loose material out of the end of the hose; split in the hose or if it appears “bleached out” • Once the plug appears to be gone, have the and lightened in color, that hose may be due for nozzleman hold the hose while bracing him- replacement. Worn-out hoses can burst during self, as stated previously. If the plug was operation, so it is important to monitor hose loosened up properly, the material should just wear and replace as necessary (Fig. 9). Also empty out of the hose as it normally would. inspect hose couplings regularly to ensure they The nozzleman should brace himself in case are in safe working condition. A compromised the plug was only partially cleared and lets coupling may become disconnected under pres- loose; and sure, causing risk to those within range. Look • If the plug persists, work to manually shake for any cracks, dents, or misshapen couplings more material out of the hose on both sides of and replace them right away. If couplings will the plug and try to clear again when it seems be in direct contact with material during your to be loosened. job, be sure to cover the couplings to prevent Use “whip checks” on all air hose connec- buildup of material. For example, you may tions at the air compressor and gunite machine. wrap the couplings with plastic. Hose fittings Consider using whip checks on material hose should be secured adequately to the hose and connections because they are also subjected to threads should be in good condition for use. high-pressure air flow. To ensure the highest-strength coupled hose assembly, manufacturers and contractors Additional equipment should use elevator bolts instead of screws to Equipment owners should follow all manu- install dry-mix couplings on hoses. Clean and facturers’ recommendations to prolong the use grease all couplings daily to prolong their use. of their machinery and accessories. Consult all When using pre-dampened materials, hoses manuals for maintenance of any other equip- may be more susceptible to build up within the ment used on the job, such as an air compressor, hose. This buildup could potentially cause a dry-mix batch plant, or pre-dampener, and keep blockage. Be sure to review the following up with regular maintenance. Proper mainte- procedure on hose blockages with all members nance also ensures that dry-mix equipment will of your crew(s). deliver maximum output and efficiency. Con- When dry-mix hose blockages occur, the sider developing a user-friendly checklist to nozzleman should: help organize and manage the daily and weekly • Hold the nozzle firmly and brace against a wall maintenance of your dry-mix equipment. or scaffold (do not lay the nozzle down); • Direct the nozzle in a safe direction; • Signal to shut off the gun/pump and water/air input; and Todd Ferguson is Marketing • Bleed off pressure at the gun. Manager for Mesa Industries, When clearing a plug out of a dry-mix hose: Inc., the parent company of • Shut down and relieve pressure as noted; four sales divisions including • Locate the plug by walking along the hose to AIRPLACO Equipment Co., find where the hard points are; Gunite Supply & Equipment, • Once the plug is located, disconnect the nearest Mesa AST Products, and Mesa location between the nozzle and the plug; Laminated Fabrics. For more • Work on the hard points with a hammer to try information, call (513) 321-2950 or visit www. to loosen them up. I would suggest using a mesa-intl.com. 42 Shotcrete • Fall 2013


2013FallShotcreteEMag
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