What does the marking "4BW" on a cylinder indicate?

The marking "4BW" on a cylinder specifically indicates that the cylinder is designed for a certain type of aviation fuel, such as aviation-grade gas. However, it is important to note that in the context of cylinders, "4BW" is commonly associated with the recertification date, particularly in regard to its compliance with safety standards.

A cylinder marked with "4BW" indicates that it has undergone the required inspection and recertification every 12 years, which is a critical component of ensuring that the cylinder remains safe for use. Proper maintenance and timely recertification help to prevent failures that could result from aging or defects in the cylinder material.

Understanding this marking is crucial for anyone involved in handling or operating such equipment, as it contributes to safety and regulatory compliance.