Multiquip manual LS400/LS500 PUMP - PUMPING INFORMATION, Snap-Joint Couplings, New Pumps

LS400/LS500 PUMP — PUMPING INFORMATION

The use of 2 -1/2” I.D. hose in these extreme cases reduces line pressures or the addition of slight amounts of water to the mix, if permissible, will permit easier pumping. The use of certain pumping admixtures may help.

If excessive pulsation exists in the hose, it is advisable to use burlap or some means of wear protection under the hose at points where the hose may wear through the outer cover; e.g. over forms, steel or sharp curbs.

SNAP-JOINT COUPLINGS

When using Snap-Joint couplings with gaskets to join hose, see that they are washed clean after each job. Keeping the hose ends clean (heavy duty) is very important for the best job setup. A thin coat of grease on the rubber gasket or dipping both coupling and gasket in water before coupling the hose will make for easier installation.

NEW PUMPS

All new pumps are‘water pressure tested” at the factory This procedure permits a thorough inspection of entire drive system and valving under simulated full load conditions.The pump owner can do the same by making an adapter to couple to the end of the discharge cone: e.g., the use of a standard 2" pipe cap with a 3/8" drilled hole in the center, screwed on to the end of hinged cone or reducer at the pump.

Fill the hopper with water after making sure that all sand and rock have been removed from manifold. Operate pump at full throttle and the 3/8" diameter hole restriction will create sufficient back pressure to make thorough inspection of all moving parts.

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.

If it is necessary to wait 1/2 hour or more for another load of concrete, to prevent setting of the mix in the system, it is advisable to consider the following factors (A through D) affecting the concrete:

A.How old is the concrete?

B.Is there an accelerator, calcium chloride, red label, etc., in the concrete?

C.The temperature of the day, 80, 90, degrees?

D.How much system you have out and how stiff was the mix you were pumping?

PREVENTING MIX SET-UP AFTER PUMP SHUTDOWN

When the pump is stopped for any reason during a pour; e.g., moving hose, waiting for redi-mix truck, the following sugges- tions are offered:

1.Leave the hopper full of concrete at the time of shutdown. It is important not to let the redi-mixdriver wash too much water into the hopper, as this could cause separa- tion of the concrete in the hopper.

2.If the shutdown period exceeds 2 to 3 minutes, turn off the engine so the vibration does not separate the mix in the hopper which can cause a blockage in the manifold when the pump is started.

3.If it is necessary to wait 10 minutes or more for another load of concrete, it is wise to start the pump and pump 6 or 8 strokes every 5 minutes to prevent setting of the mix in the system. If waiting time is excessive, it would be wise to wash out the pump and hoses and start over when the new truck arrives.

4.When pumping stiff mixes and there is waiting time between redi-mix trucks, it is advisable to add some water to the last hopper of material and “hand mix” to ensure an easier start with the following load.

5.When the pumping job requires a stiffer mix, the following method is suggested for starting:Take a water hose with a nozzle on it and apply water with a fine spray to the concrete as it comes down the redi-mix chute into the pump hopper after the slurry procedure is completed and you are ready to start pumping.

MAYCO LS400/LS500 PUMP — OPERATION AND PARTS MANUAL — REV. #6 (09/19/11) — PAGE 33