Hoses are used across industries to transfer various types of fuel gases for welding and cutting. Fuel gases such as acetylene, propane, and butane utilize different types of welding hoses. These hoses may differ in terms of their lengths and thicknesses; however, they are commonly distinguished based on their connection sizes – A, B, and C. A welding hose is made of three parts – a swivel nut, a nipple with a seating surface, and a hose clamp or ferrule. The seating surface of the nipple is designed such that it matches with the internal seat of the regulator or torch connections. A clamp helps lock the gas on the hose end of the nipple. The connection sizes are standardized by the Compressed Gas Association of the US. What is the best connection size for oxy-acetylene welding hoses or oxygen welding hoses? Read the post to know the answers.
Typical Uses of A, B, and C Size Hose Connections
Each A, B, and C connections have a typical hose stem, connecting nut, and ferrule. The “B” size nipple is distinguished by its screw-type stem; however, “A” size nipple with its push-type stem. The following are the typical uses of A, B, and C size connection for gas welding hoses.
- Size A: This connection is ideal for low volume gas work, and is widely used in small regulators and torches used during gas welding of HVAC parts, DIY automobile parts, and so on.
- Size B: Be it oxy-acetylene welding hose, oxygen hose, propane hose, or acetylene hose – they all use size B connections. Thus, it is one of the most common connections for gas welding hoses. The B size connections are available in various nipple sizes such as 3/16-in., 1/4-in., 5/16-in., and 3/8-in, with left- and right-handed threads. The oxygen hose threads are usually right-handed, whereas acetylene and fuel gas hose threads are left-handed. These size B hoses have identical nipples. “B” Size fittings are considered ideal for applications that demand medium gas volumes. There are separate B (inert) size fittings for applications using inert gases.
- Size B for Inert Gases: The thread for size B of inert gases is slightly larger than the thread for size B of acetylene and oxygen hoses. The main difference between the Size B for acetylene and Size B for inert gases lies between their connection nut, which has a male thread. The female thread can be found in the fixed connection of the hose of the Size B for inert gases. You can find these hoses in right-handed as well as left-handed thread versions. These “B” size fittings are mainly used for gas welding hoses during TIG and MIG welding.
- Size C: These hose connections are designed for heavy-duty and large connections. They are widely preferred for industrial applications such as scarfing and cutting in environments where high gas volumes are required. All regulators that connect to station drops use C-size connections as CGA cylinder connections are not allowed on station drops.
All welding and cutting hose connection sizes discussed here are designed for a maximum working pressure of 200 PSIG. The choice of the right connection type will depend on your application requirements. It is always recommended to use the right hose connection for your gas welding hoses, preferably sourced from the manufacturer of the equipment. Rexarc is one of the leading manufacturers of acetylene gas plants and gas cylinders in the US. The company is also one of the leading station drop manufacturers in the US, providing A, B, and C type welding hose connections to meet the application requirements of its customers.