Match Operating Conditions and Media
For standard water supply and drainage, choose galvanized ductile iron fittings; for corrosive chemical environments, opt for 304/316 stainless steel; for high-pressure pipelines, prioritize malleable iron; and for fire protection systems, select specialized fittings that comply with relevant fire safety standards.
Verify Specification Compatibility
Accurately measure the pipe's outer diameter and select fittings with the corresponding DN (Nominal Diameter) rating. Ensure the fitting's pressure rating meets or exceeds the system's design pressure to prevent leaks caused by size mismatches.
Distinguish Between Coupling Types
Use flexible couplings for hot water lines or outdoor piping subject to significant temperature fluctuations to accommodate thermal expansion and contraction; for indoor fire protection piping with stable temperatures, rigid couplings may be used to balance stability and cost.
Check Quality and Qualifications
Prioritize branded products that possess complete certifications and valid inspection reports. Verify that the gasket material is compatible with the conveyed medium to prevent premature aging or failure caused by substandard seals.