Q1: Oxygen cylinders used for autogenous (cutting/welding) purposes are

ANS:A - seamless & made of steel.

Oxygen cylinders used for autogenous (cutting/welding) purposes are typically seamless and made of steel. Here's why:

1. Seamless: Oxygen cylinders are typically manufactured as seamless tubes to ensure uniform strength and integrity. Seamless cylinders are less prone to leaks or failure compared to cylinders with welded seams, providing greater safety during use.
2. Made of steel: Steel is commonly used for manufacturing oxygen cylinders due to its strength, durability, and resistance to high-pressure conditions. Steel cylinders are capable of withstanding the high pressures required for storing and transporting compressed oxygen safely.
3. Heat treated before use: While oxygen cylinders may undergo various manufacturing processes, including heat treatment, to ensure their mechanical properties and safety, this is not necessarily specific to autogenous purposes. Heat treatment may be employed as part of the cylinder manufacturing process to enhance the strength and durability of the steel material.
4. Not made by sand casting: Sand casting is not typically used for manufacturing oxygen cylinders due to the precision and quality requirements of such critical components. Sand casting may be suitable for producing less critical components with simpler shapes, but for high-pressure applications like oxygen cylinders, more advanced manufacturing processes are typically employed to ensure reliability and safety.

In summary, oxygen cylinders used for autogenous purposes are generally seamless and made of steel to ensure strength, durability, and safety during cutting and welding operations. They are not typically made by sand casting, and while heat treatment may be part of the manufacturing process, it is not specific to autogenous purposes.