Frequently Asked Questions
QUESTION: Is there a difference between the top and bottom of an air bag?
ANSWER: Technically, there is not a top and bottom on an air bag. One side of the air bag features operating instructions to provide reinforcement during an evolution.
QUESTION: When performing a twobag lift, is it necessary to pre-fill the top bag with a small amount of air to assure expansion when contact is made with the load?
ANSWER: No. The air bag will open. Always inflate the bottom (larger) bag first, then the top (smaller) bag. In deflating, reverse this operation.
QUESTION: Can cribbing be placed on top of an air bag?
ANSWER: Yes. If you need to protect the air bag from sharp objects on the load, you can place cribbing on top. However, building a high cribbing stack on top of the air bag is not recommended due to stabilization factors. Under certain conditions, it’s necessary to provide some 4″ x 4″ or 2″ x 4″ on top of the air bag to protect the bag’s surface.
QUESTION: Can you determine the direction of a lift with an air bag?
ANSWER: Yes. The bag’s center always determines the direction of the lift. By using wedge cribbing, you can direct the bag to push left, right, or on angles. For example, when lifting a cylindrical tank, use 45° angled wedge blocks and build a cribbing stack on top. The flow of the air bag can be directed to the center of the tank. This permits the tank to be picked up straight without perfectly centering the bag.
QUESTION: If I run out of air during an evolution, how do I change the air tanks?
ANSWER: Air tanks can be changed in the middle of an evolution. Simply shut down the air tank. Bleed air out of regulator until all gauges read zero. Close the petcock valve on the regulator and disconnect it from the tank. Connect a new tank. Return the regulator to operating pressure. Open the air tank, adjust the regulator’s low-pressure discharge gauge to 150 psi and open the petcock. You are now feeding another air supply to the bags. You do not have to deflate the bags or shut down the valves.
QUESTION: Can air bags be punctured?
ANSWER: Yes. Air bags can be punctured when lifting a heavy load or a sharp pointed object, or on the base of a .5-inch bolt. To prevent this, place a 2″ x 4″, 2″ x 6″, or cribbing protection underneath the bolt so it spreads the weight across the bag’s surface area.
QUESTION: What causes air bags to “pop out” from underneath a load?
ANSWER: Not centering them properly under the load or positioning the smaller bag on the bottom instead of on the top. When performing a two-bag lift, you must center the bags, larger on bottom and smaller on top. Then center both bags under the load to be lifted. The load will be lifted with the center of the bag, not its side or edge.
