Matching Standards and Operating Conditions
Select fittings primarily based on national standards such as the Code for Installation and Acceptance of Automatic Sprinkler Systems(GB 50261). Choose standard 1.0 MPa fittings for general fire protection systems and thickened 1.6 MPa fittings for high-pressure zones; incorporate a 20% pressure margin to account for water hammer effects.
Selecting the Right Material
Choose galvanized carbon steel fittings for general water supply, drainage, and fire protection applications. Opt for 304 or 316 stainless steel fittings for chemical or pharmaceutical environments where corrosion resistance is required. Pair fittings with NBR oil-resistant gaskets for pipelines carrying oily media, and use EPDM gaskets for hot and cold water systems.
Verifying Size and Type Compatibility
Ensure the pipe outer diameter tolerance is within ±0.5 mm and matches the corresponding DN specification. Select flexible couplings for outdoor pipelines or hot water lines subject to significant temperature fluctuations, and rigid couplings for standard indoor fire protection piping; use grooved flanges for butterfly valve connections.
Checking Product Qualifications
Confirm the product includes a certificate of conformity, a unique fire protection identification code, and a third-party test report. Ensure the fitting surface is free of defects and the gasket markings are complete and legible; reject products that are unmarked or do not meet standards.