Multiquip C-30HD Pumpingtips Andtrouble Shooting, Follow these instructions carefully

PUMPINGTIPS ANDTROUBLE SHOOTING

1.The effects of heat and excessive time on concrete: Hot concrete, commonly referred to as a hot load, is concrete that has been in the redi-mix truck in excess of 2 to 3 hours. On a hot day, this amount of time is even less. A brief explanation of why heat and time affect concrete: Concrete starts setting by drying up through a chemical reaction.The catalyst to this reaction is heat.When pumping a hot load, it is important to remember that when you have to stop pumping for any reason, add water to the concrete in the hopper and hand mix and move concrete in the hose every 5 minutes. If the shut down time becomes too long, wash out immediately.

2.ADMIXTURES: A remixtures that are designed into the concrete mix by the redi-mix company or an architectural engineering company. This section lists common admixtures and a brief explanation of their function.

A. POZZOLITH 300 R or the equivalent acts as a water retarder and a lubricant. On a lean mix, long pushes, stiff mixes, and vertical pushes, Pozzolith 300 R helps pumpability.

B. MBVR, air entraining, acts as a lubricant.

C. CALCIUM CHLORIDE, commonly referred to as C.C., is used as an accelerator. When pumping a load with calcium chloride, it is recommended that you wash out if the waiting time between delivery trucks becomes too long.

D. SUPER PLASTICIZERS, acts as an accelerator. The concrete will look very wet after the super plasticizer is added, but will begin to set up very fast. Wash out immediately if you do not have a truck waiting. Super plasticizers are used mainly on commercial jobs.

E. RED LABEL, acts as a water retarder and an accelerator. Red label will be used mainly on commercial jobs.

F. FLY ASH, is used to help increase the strength of the concrete and decrease the cement content per yard. This is one of the most common admixtures used.

NOTE: All admixtures will be shown on the redi-mix concrete ticket. Before starting the pumping job, ask the driver of the redi-mix truck to see the concrete ticket and note the admixtures that exist and take the proper action.

3.When pumping long distance or pumping stiff mixes, you can expect a drop in volume compared to shorter lines and wetter mixes due to the change in valve efficiency or cavitation.

4.Leaking manifold seals or hose coupling gaskets which leak water can cause separation and subsequent jamming at that point.

C-30HD OPERATING INFORMATION

5.Damaged hoses with internal restrictions can cause blockages.

6.If a blockage occurs in a hose, “walk the hose” until you find the point of trouble.The hose will be soft immediately past the blockage. If this happens at the start, disconnect the hose at the first coupling past the blockage. Elevate the hose at that point with the blockage area hanging down. Note: Use extreme care! The hose line is under pressure and can cause serious injury. Using a hammer, you can pound the down-stream edge of the packed area until it is free to flow. Shake all of the sand and gravel out to the end of the hose. Before reconnecting the hose, start the pump and run a small amount of concrete out to the end of the hose.This will assure that all of the separation is out of the hose.

7.The manifold is plugged if the volume at the discharge end of the hose stops, and the hose is soft. The drive belts will start to slip and the engine will lugdown.

To clear a plugged manifold, great care must be taken as a dangerous condition will exist due to pressure build-up inside the manifold.

Follow these instructions carefully:

7.1Stop the pump. Switch off the engine.

7.2DO NOT open any of the delivery system joint clamps.

7.3The senior experienced operator must warn all others to stand at least 20 feet away from the machine and turn their heads away from the manifold.

7.4The operator must position himself/herself away from the hinged side of the manifold.

7.5Wearing safety glasses, grasp the clamp arm weldment and carefully pull it open to the primary (safety) position. STOP count to 20. This will allow the pressure to release.

7.6After the pressure has been released, open the clamp arm weldment and swing the hinged discharge cone open.

7.7Remove blockage with around a 2-foot length of reinforcing steel rod. Flush the manifolds with water. Make sure the (3” x 2”) reducer is clear of any blockage before closing the discharge cone.

7.8After the blockage has been cleared and the pump manifold has been thoroughly flushed with water, close the hinged discharged cone and lock into place.

7.9Before reconnecting hose to the reducer, start the engine and pump two or three shovels of concrete through the reducer.This will insure that all the blockage has been cleared.

C-30HD — PARTS & OPERATION MANUAL — REV. #4 (03/06/01) — PAGE 15