When it comes to airbag systems, there are hybrid inflators and pyrotechnic inflators. Learning the difference between these two types of systems will help when replacing tubing. Hybrid inflators have gas, where as pyrotechnic inflators utilize a gas-producing material. A chemical chain reaction occurs when it's time for the bag to deploy, and a hybrid inflator will have gas ready to ignite. For pyrotechnic inflators, a propellant will be the end of the chain reaction.
Unlike hybrid inflators, pyrotechnic inflators utilize casing for a gas-producing substance. This gas-producing substance is what causes the airbag to be inflated at the end of the chemical chain reaction. There is less toxicity involved with a pyrotechnic inflator, which is why there is has been a dramatic shift in airbag manufacturing over the past decade. Hybrid inflators, with their increased toxicity, are also less cost-efficient than pyrotechnic inflators.
Airbag systems are designed to explode quickly and with little to no danger to the passenger. The ultimate goal is to explode before the passenger contacts the part of the car associated with the airbag location. This means that chemical chain reactions must be utilized to expedite the inflation. Both hybrid and pyrotechnic systems are successful, but which one you have will determine what kind of tubing you need.