The danger involved with the brake bend is often underestimated

Just as a comparison: in the fire brigade, two men hold a 75 mm hose with a water pressure of 8 to 10 bar!

A sensible solution

It is forbidden to use brake bends at the top of the boom, resp. on the end hose of concrete placing booms due to safety reasons. Also forbidden is the use of delivery hoses with metal nozzles.

It is impossible for a man at the end hose to hold the hose when a block-age is freed from the concrete pumps. The force set free when a blockage is released from concrete pumps is so great (up to 10 tonnes!) that it cannot possibly be held back by a man at the end hose. An example here might help to elucidate the danger: the so-called ‘B’ hose with 75 mm ø and a water pressure of 8 to 10 bar, used by the fire brigade must be held by two men. For truck-mounted
concrete pumps, however, delivery is usually carried out at 85 bar and the line diameter is as a rule 125 mm!

To avoid concrete splashing, the PM Parts Sales offer, by the way, a pin pour. With this accessory, all metal parts are covered by plastic so that there is no danger of injury if they are used correctly.

The pin pour functions like a zoom-type adjustable nozzle which adapts its present cross-section to the amount of concrete flowing at the time. In the field, this means that the concrete flows out of the delivery line uniformly and jerk-free. The pin pour has of course been given the ‘all-clear’ by the Employers’ Liability Insurance Association.