The tee, a malleable cast iron pipe fitting, is a core connector for diverting and merging flows in a piping system. Its name vividly describes its three-way connection. It acts as a “transportation hub” in the pipeline, capable of dividing one fluid or medium into two, or combining two fluids into one. It is an essential component for building complex branched pipe networks.
In terms of structure and function, a tee is typically T-shaped or Y-shaped, with one inlet and two outlets (or vice versa). Each of its three ports is threaded with standard pipe threads to achieve a tight connection with the pipe. Tees are primarily divided into two types based on the diameter relationship between the three ports:
1. Equal-diameter tee: This is the most common type, with all three ports having identical diameters and typically designated “T.” It simply diverts or merges flows without changing the diameter of the branch pipes. For example, if a branch pipe from a main water supply to a wash basin is connected, an equal-diameter tee is sufficient. 2. Reducing Tee: One of the ports has a different diameter than the other two, typically designated “T(R).” This reducing port is typically located in the branch direction. Its core function is to change the diameter of the branch pipe while dividing or combining flows to meet varying flow or pressure requirements. For example, a reducing tee is necessary to connect a large-diameter main gas line to a smaller-diameter pipe running to a gas cooker.
When selecting a reducing tee, pay attention to the following technical parameters:
Nominal Diameter: The standard sizes of the three ports must be clearly defined, such as DN15, DN20, DN25, etc. Reducing tees must be accurately marked with the “large diameter x large diameter x small diameter” specification.
Thread Standards: As with all malleable cast iron pipe fittings, it is crucial to strictly distinguish between British and American pipe threads and ensure they match the thread standard of the pipe being connected; otherwise, a seal will not be achieved.
Material and Corrosion Resistance: Malleable cast iron (malleable iron) provides the tee with sufficient strength and impact resistance. Surface treatments include galvanizing (high corrosion resistance, suitable for general use and humid environments), black casting (original casting, requires secondary corrosion protection, low cost), and varnishing (with anti-rust paint, moderate corrosion resistance). The choice depends on the medium being transported and the corrosiveness of the environment.
Tees have a wide range of applications. In building water supply and drainage systems, they distribute water from risers to residents on each floor; in fire sprinkler systems, they connect main pipes to distributed branches; and in industrial piping, they are used for instrumentation points and equipment flow diversion.
In short, malleable cast iron tees, with their stable structure, reliable connection, and flexible specifications, are the preferred solution for fluid distribution and collection in pipeline projects. Choosing the right tee that meets the pressure rating, medium requirements, and thread standards is key to ensuring hydraulic balance, proper layout, and safe operation of the entire piping system.
Post time: Oct-22-2025