Classification by Function
Connection and Sealing Types
Includes rigid couplings, flexible couplings, mechanical tees, grooved flanges, etc.
Primary function: To achieve sealed pipe joints and ensure pressure-bearing and leak-proof performance at connection points.
Transition and Routing Types
Includes elbows, tees, crosses, reducers, end caps, etc.
Primary function: To change pipeline direction, facilitate flow splitting or merging, and adapt connections between pipes of different diameters.
Classification by Material
Cast Iron
Lower cost; suitable for standard fire protection and water supply applications; surfaces are typically treated with paint or plastic coatings for corrosion resistance.
Stainless Steel
Commonly available in 304 and 316 grades; offers high corrosion resistance; suitable for chemical, pharmaceutical, and other applications requiring specialized corrosion protection.
Other Materials
Includes grooved plastic fittings compatible with HDPE piping; widely used in building drainage and rainwater harvesting systems.
Classification by Connection Scenario
Straight-Through Grooved Types
Directly connects two pipes of the same diameter using a coupling; represents the most basic type of connection fitting.
Mechanical Hole-Cutting Types
Allows for branch line connections by cutting a hole directly into the main pipe without severing it; includes mechanical tees, mechanical crosses, etc.
Conversion and Adapter Types
Includes grooved-to-threaded reducers, grooved flanges, etc., enabling flexible transitions between grooved connections and threaded or flanged connections.