Key Points for Pipe Fitting Selection

Pipe fittings are essential components in connecting pipe systems. They connect pipe sections together through threaded interfaces for transporting gas, liquid, or other media. Proper selection of pipe fittings is crucial for ensuring the safety, efficiency, and durability of the system. Here is a pipe fittings selection guide, covering material selection, thread types, sizes, and other relevant factors.

Material and Rated Temperature

Stainless Steel. It has strong corrosion resistance, and is suitable for places with corrosive liquids or high sanitary requirements, such as food processing and chemical industries, with a maximum working temperature of 1000 °F / 537 °C.
Carbon Steel. It is suitable for environments not involving strong corrosive media, with a maximum working temperature of 375 °F / 190 °C.
Brass. It is commonly used in water and gas pipelines, and has good corrosion resistance and mechanical performance, with a maximum working temperature of 400 °F / 204 °C.

Thread Types

NPT thread
ISO/BSPP straight thread
ISO/BSPT tapered thread
Metric thread
SAE/UNF thread

Dimensions and Specifications

Dimensions. When selecting pipe fittings, ensure that their dimensions match the connected pipes. Common sizes range from 1/8" to 4" or larger.
Pressure rating. Choose the appropriate pressure rating based on the maximum working pressure of the system. Fittings of different materials and designs have different pressure ranges they can withstand.

O-ring Materials

NBR. Maximum working temperature 230 °F / 110 °C, minimum working temperature -13 °F / -25 °C.
FKM. Maximum working temperature 400 °F / 204 °C, minimum working temperature -20 °F / -28 °C.
Copper. Maximum working temperature 400 °F / 204 °C, minimum working temperature -325 °F / -198 °C.

Connection Types

Table 1: Pipe Fitting Types and Specific Connection Method
Type	Specific Method
Hex nipples	Hexagonal outer shape with male thread fitting
Hex long nipples	Hex long nipples + male thread fitting
Hex couplings	Hexagonal outer shape+ female thread fitting
Union ball joints	Pipes or hoses can freely rotate during use
Closed nipples	The middle connecting part of two threads is short, both threads are male threads
Special pipe nipples	Round pipe + male thread fitting
Adapters	One end female thread fitting + one end male thread fitting
Reducing bushings	Female thread fitting + male thread fitting, connecting pipes of different diameters
45° female elbows	Both ends are female threads, achieving a 45° directional change
45° street elbows	One end female thread fitting + one end male thread fitting, achieving a 45° directional change
Female elbows	Both ends are female threads, achieving a 90° directional change
Male elbows	Both ends are male threads, achieving a 90° directional change
Street elbows	One end male thread fitting + one end female thread fitting, achieving a 90° directional change
Female tees	All three interfaces are female threads
Male tees	All three interfaces are male threads
Female branch tees	Branch pipe female thread + two side pipe male threads
Male branch tees	Branch pipe male thread + two side pipe female threads
Female run tees	One side pipe female thread + one side pipe male thread + branch pipe male thread
Male street tees	One side pipe male thread + one side pipe female thread + branch pipe female thread
Female crosses	All four interfaces are female threads
Male crosses	All four interfaces are male threads
Pipe caps	Pipe fittings used to close the end of a pipeline
Hollow hex plugs	Internally hexagonal + male thread design
Pipe plugs	Externally hexagonal + male thread design

By considering the above factors, you can more reasonably select pipe fittings that suit your specific needs, ensuring the safety and efficiency of the pipeline system. If you encounter any problems that cannot be resolved when selecting pipe fittings, please feel free to contact us.