Multiquip C-30HD operation manual When pumping vertically

7.10Shake out around 2 feet of concrete before reconnecting hose to pump. After this is done, connect hose to pump and resume the pumping operation.

8.If it is necessary to wait 1/2 hour or more for another load of concrete, it is advisable to consider the factors affecting the concrete that is already in the pump and system. To prevent setting of the mix in the system: 1) how old is the concrete ? 2) is there an accelerator, calcium chloride, red label, etc., in the concrete ? 3) the temperature of the day, 80, 90, degrees? 4) how much system you have out and how stiff was the mix you were pumping? If, for any reason, the mix should set up in the system, the following procedure is suggested:

Note: Use extreme care! The hose is under pressure! Disconnect the hose from the pump and wash the pump out immediately. Reconnect the hose and fill the hopper with water. DO NOT try to push all the concrete out of all of the hose line at one time. For example: If you had 200 ft. of system out, you would disconnect each hose. Clean it out by pushing water through the first hose off the pump, then continue progressing through all the hoses, until all the system is clean. If waiting time is excessive, it would be wise to wash out the pump and hoses and start over when the new truck arrives. This can be avoided by being attentative to the pump and system, also taking into consideration the above 4 factors affecting the mix.

9.“Down-hill pumping” can be difficult on some jobs.The slurry procedure would be the same as explained on the pages titled Operating Suggestions. It is suggested that a sponge 2”x 4”x 6” be placed in the hose before the start of pumping. Wet the sponge before placing it in the hose. The reason for using the wet sponge is to keep the slurry from running too far ahead of the concrete and so reducing the possibility of separation. When the pump is stopped, the material can flow slowly down, due to gravity, and cause the hose to collapse.When pumping is resumed, you can expect a blockage at the point of hose collapse. To prevent this from happening, the hose can be “kinked off” at the discharge end when the pump is stopped to prevent the gravity flow of the material in the hose. The use of stiffer mixes when pumping down-hill will decrease gravity flow of the material in the hose and will assure a smoother operation between the cam roller bearing and cam plate. As with any job, make sure that the hose and the couplings are in good workable shape.

C-30HD OPERATING INFORMATION

10. When pumping vertically:

A. When pumping vertically up the side of a building, above 40 feet, we would recommend the installation of steel pipe securely fastened at intervals as necessary to support the pipe. Ninety degree, long radius pipe sweeps should be installed at the top and bottom of the steel line. Use a 25 ft. hose, or short section, off the pump; and for the balance of the horizontal distance to the vertical line, use steal pipe. This type of installation has been satisfactory on many jobs being pumped in excess of 100 feet high. Line pressures are always less using steel pipe as compared to hose.

B.When pumping vertically, using all hose, it is recommended not to go higher than 50 feet with hose. The hose should be tied off at intervals of 10 feet, if possible. Special attention should be given when tieing the hose off at the top as the hose will have a tendency to stretch when filled with concrete. This will increase the possibility of a blockage at the point where the hose is tied off. To avoid this, a long radius of 90 degree elbow is recommended. The suggested place to tie off is on the hose, under the clamp. Note: It is strongly recommended that pipe be used on all vertical pumping for safety and convenience.

If it is absolutely necessary to use hose, then use this section as a guide.

11.If the volume at the end of hose starts to decrease gradually and eventually almost stops, it is quite likely that the valve seats have had excessive wear and need replacement. Once they have reached a certain wear point, they may “channel out” rapidly and material will reciprocate past the ball on each stroke. The hollow steel ball should be replaced when it starts to show dents or appears to be badly worn. Sand and aggregate materials in some areas are extremely sharp and hard and therefore highly abrasive. Under these conditions when pumping stiff mixes, or to high elevations which cause line pressures, it will be noted that valve components may have short wear life. If this condition exists, it is advisable to remove the manifold only, and inspect the lower seat at the end of each day. If it appears that the seat is beginning to “channel out, replace before starting the next day’s pour. The upper valve seat can be inspected after each washout by running your finger around lower edge of seat where the ball makes contact.You can reach this from the inside of the hopper. Be sure that the engine is turned off.

PAGE 16 — C-30HD — PARTS & OPERATION MANUAL — REV. #4 (03/06/01)