Overview of Grooved Fittings

Grooved fittings are a new type of steel pipe connection fitting, also known as clamp or coupling connections, and offer many advantages.

The "Code for Design of Automatic Sprinkler Fire Extinguishing Systems" stipulates that pipe connections in the system shall use grooved couplings, threaded connections, or flanged connections. For pipes with a diameter equal to or greater than 100mm in the system, flanged or grooved couplings shall be used in sections.

Grooved fitting connection technology, also known as clamp connection technology, has become the leading technology for liquid and gas pipeline connections. Although this technology was developed later in China than abroad, it has been quickly accepted by the domestic market due to its advanced nature. Since its development began in 1998, after just a few years of development and application, it has gradually replaced the two traditional pipeline connection methods: flanged and welded connections. The technology has not only become more mature and widely recognized by the market but has also received active guidance from national regulations and policies.

The application of grooved fitting connection technology makes complex pipeline connection processes simple, fast, and convenient, representing a significant step forward in pipeline connection technology.

Introduction to Grooved Fittings

Grooved fittings include two major product categories:

① Connecting and sealing fittings – including rigid couplings, flexible couplings, mechanical tees, and grooved flanges.

② Transition/adapter fittings – including elbows, tees, crosses, reducers, blind flanges, etc.

The grooved connecting fittings that serve the connecting and sealing function mainly consist of three parts: a rubber sealing gasket, a housing (coupling), and tightening bolts. The inner rubber sealing gasket is placed over the outer side of the pipes to be connected, matching the pre‑rolled grooves. The housing (coupling) is then fitted over the gasket, and finally tightened with two bolts. Due to the unique sealable structural design of the rubber gasket and housing, grooved couplings provide excellent sealing performance, which actually increases as the internal fluid pressure rises.