1. Tube Body – This is the outer shell of the tube and is the main pressure-containing unit.
2. Tube Filler – This is a material, often a solid or a liquid, placed between the walls of the tube body to provide a cushioning effect and reduce thermal expansion.
3. Tube O-Ring – An O-ring is placed around the tube body to provide a seal between it and the tube cap.
4. Tube Cap – The cap is used to close the tube and can be removed to allow for filling or emptying of the tube.
5. Tube Plug – Plugs are used to seal the tube and provide a connection for a vent hose or other instrumentation.