Why are gas cylinders fitted with caps?

Thread Content

Since the valve caps on gas cylinders are mostly made of copper alloys, they are relatively fragile. Although some are made of steel, their structure is smaller than that of the cylinder body; when screwed onto the cylinder body, it creates a right angle between the bottle neck and the valve cap connection. This area is both a weak point and a protruding part of the cylinder body, making it most susceptible to mechanical damage or external impacts. If, during handling, storage, or use, the gas cylinder is accidentally damaged due to falling, dropping, rolling, or being struck by other hard objects, it is possible for the connection between the cylinder valve and the cylinder neck to break completely at that junction. Consequences of a broken bottleneck or valve: When the valve on an oxygen cylinder breaks, the high-pressure gas inside the cylinder, at 150 kilograms per square centimeter, escapes uncontrollably. The force generated by this escaping gas causes the cylinder to shoot in the opposite direction, which can damage machinery, buildings, and even result in injuries or deaths ； When the valve of an acetylene gas cylinder breaks, the flammable gas escapes and mixes with air to form an explosive mixture, which explodes when exposed to an open flame. The high-speed gas ejected from the bottle can cause more severe secondary accidents (such as fires, explosions, poisoning, etc.), depending on the properties of the gas inside the cylinder. If the bottle contains a flammable gas, static electricity generated by the intense friction from high-speed spraying, or exposure to other ignition sources, can cause combustion and explosion. On the other hand: since the bottle valve is exposed, it is prone to being contaminated by dust or oils during handling and storage, which poses a risk. Wearing a safety helmet can prevent dust or oily substances from sticking to and entering. To eliminate the aforementioned risks, it is required that bottle manufacturing units equip steel cylinders with safety caps at the time of production. When using the gas, remove the safety cap and place it in a designated location; after use, put the cap back on and tighten it properly – never discard it carelessly. Never forget to wear a safety helmet when lifting and loading.