The fittings on acetylene hoses are designed with what type of threads?

The fittings on acetylene hoses are specifically designed with left-hand threads to prevent any accidental connection with oxygen hoses, which have right-hand threads. This unique threading system is a crucial safety feature in welding operations, minimizing the risk of using the wrong gas, which could lead to dangerous situations such as explosions or fires. The left-hand threading is a distinctive characteristic that ensures compatibility only with acetylene equipment, reinforcing safe practices in environments where these gases are used.