This PowerPoint is intended as a general review of high-pressure air bag set-up and safety practices. There are various different air bag systems currently used in Snohomish County. Always refer to your departments SOP/SOG’s as well as manufacturers recommendations prior to use. All high-pressure airbag operations should be performed in conjunction with proper stabilization practices. See Snohomish County Training Officers 2014 (First Quarter) “Vehicle Stabilization” http://www.snocountychiefs.org/divisions/fire_t raining_officers/quarterly_training.cfm
Safety: Wear appropriate protective clothing, helmet, eye protection and gloves. Never exceed maximum inflation pressure (usually 118- 135 psi). Never connect or disconnect system components while pressurized unless a safety in-line relief valve is in place. Always ensure you are positioned on the opposite side of the expected load movement. Never be below a load that has not been blocked or cribbed. Stay on your feet! Always center the load on an airbag (can violently eject). Never stack more than two air bags on each other during operations.
Safety continued: Always place the smaller air bag centered on the top of the larger. Inflate only enough to achieve desired lift. If the desired object to be lifted has a small surface area of contact, always use plywood/ dimensional lumber or other rigid material between the bag and the object to distribute the load. Always inflate slowly to prevent load shifting and stabilize/block as you go. Ensure all valves between the air source and bags are in the closed position prior to turning on the air source. Ensure the air bags are not in contact with hot or sharp objects prior to operation.
Safety continued: Always have the bags connected to the air hose prior to placing under the load. It is a good general practice to inflate the bag to only 75% of its stated lifting capacity. This is to avoid the “pillow” effect and reduces the potential for the bag to slip or kick out. When stacking two bags the maximum tonnage of the smaller bag is the maximum that can be lifted. Change the air supply when the bottle drops to 100 psi. Reduce rated bag tonnage capacity by 50% to calculate the maximum tonnage capacity when lifting height exceeds 1” i.e., a 30 ton bag with a maximum lift of 10” will lift 30 tons 1” or 15 tons approximately 7.5”. Only 1 person should give the controller the order to lift.
Air bags come in a variety of shapes and lifting capacities. Three of the most common in use are the 15, 29.9 and 41.5 ton. Information and warning labels clearly indicate each air bags capabilities and operating pressures. Additional markings are beneficial for capacity identification during emergency operations and under poor lighting conditions.
The dual “deadman” safety relief and control valve is one type of valve commonly found in Snohomish County. It has a single input from the air source and two outputs for dual bag operations. Each output has a gauge for reading the pressure within each bag during use. The control valve has quick disconnect hose fittings and dual push-button controls to apply and release air pressure to either one or two lift bags.
Air hoses come in a variety of colors and are all inter changeable within the system. When inflating or deflating air bags the hose color determines the commands for each individual bag. Example: “up slow on yellow” or “down slow on red”. In-line relief valves are quarter turn shut-off valves which allow the controller to be disconnected while maintaining pressure within the air bag. This is common for repositioning during multiple bag lifts.
The most common supply for air bag systems is an SCBA bottle. A large portion of Snohomish County use 4500 psi Scott bottles which need an adaptor to connect to the system. There are two types of pressure regulators found with air bag systems. Each has a gauge indicating delivery pressure and supply pressure. Piston Diaphragm
Assemble all of the components: Seat adaptor onto air bottle
Connect airline from regulator to the controller
In-line relief valves should be connected to either the controller end or directly to each air bag in use. Shown in the open position. Relief valves should always be closed prior to charging system.
Connect airline from the controller to the air bag with the in-line relief valve located at the desired end.
Turn on the air supply. Adjust the regulator to the appropriate pressure.
Once the air bag system is assembled, move it into position for the lift (Scene Survey ‐ INNER and OUTER Circle with stabilization i.e. chalk, keys & parking brake should already be complete)
Prepare to receive commands for the lift operation.
It’s 07:00 on a Friday morning and you’re dispatched to a Car vs. Pedestrian. Multiple callers report a child has been struck by a vehicle while waiting for the school bus. Upon arrival you note a crowd has gathered around the scene and a witness states the child is still trapped under the vehicle.
This is what you see. You note the patients left leg is rolled on top of his right and pinned under the rocker panel.
What are your scene consideration? What resources will be needed for the operation? What stabilization methods will need to be used for an air bag operation?
Gather all needed equipment for a high-pressure air bag operation. Review air bag safety and stabilization practices with your crew. Assemble the air bag system and lift a vehicle utilizing proper stabilization techniques. Safely lower vehicle.