Hose pipes, one of the efficient delivery systems used extensively in the environmental construction industry, pose a major risk when air trapped in them becomes compressed temporarily. This compressed air when being released causes the hose to whip powerfully creating a hazard to nearby workers, machine operators and equipment. The risk is even higher these days because most hoses are connected to some type of hydraulic systems.
Data shows that hose whipping accidents are quite common, particularly in cases of pumping concrete. Hose whipping may cause serious mishaps and may sometimes prove to be fatal. The occurrence may injure workers involving the company in hassling legal lawsuits, compensation procedures, and loss of manpower and work.
Causes of Hose Whipping
Air in the delivery system typically compresses when it gets trapped on being pushed from behind but its movement ahead in the hose is restricted. An easy release of air does not lead to whipping. But, absence of a vent builds up the energy making the trapped air potentially dangerous. Damages may also occur from splattering of the deliverable at the time when compressed air is released.
Air may enter the hose when –
• Starting the equipment.
• Using the pump in reverse.
• Using the delivery system even after the deliverable has been completely discharged.
• Removing a blockage.
• Letting the deliverable fall freely after shutting down the pump.
• Consistency of the deliverable is too dense to be released smoothly. Such deliverables invariably come out of the hose in a stop and go manner raising the incidence of air entering the hose.
Preventing Hose Whip Accidents
Simple safety measures help enhance loss prevention from hose whipping –
• Move away from the hose until the material to be delivered starts coming out of the hose.
• Use appropriate personal protective equipment (PPE) to avoid injuries from debris coming out with pressurized air.
• Use hose whip checks, simple gadgets which prevent whipping of the hose. Different types of whip checks allow effective whipping control. Strong stocking type restraints prevent sudden hose movements. A different type of steel cord restraint minimizes the whip in the event the hose gets detached from the main pipe.
• Perform job safety analysis (JSA) of all losses and near losses. This assessment management tool has been designed specifically to reduce the risk of executing a task to as low as reasonably practicable.
• Educate all personnel about hose whipping accidents, how they occur and their prevention. Customize training according to workers role.