Short answer: Steel pipe fittings and flanges connect, redirect, branch and terminate piping systems. Selection depends on pressure class, material, end connection and standard — most commonly ASME B16.5/B16.9, ASTM A234 and API 6A for high-pressure service.
At a Glance
Common Fitting Types
Elbows change direction, tees branch flow, reducers change diameter, caps close lines and couplings join straight sections. Forged fittings are rated for higher pressure than wrought butt-weld fittings. Seamless Vs Welded Steel Pipe covers the pipe itself.
Flange Pressure Classes
ASME B16.5 classes define pressure-temperature ratings. Class 150 suits low-pressure utility piping; Class 300/600 cover general process; Class 900 and above are used in oil & gas, hydrogen and wellhead service. Always check material group and temperature derating.
Materials & Standards
Carbon steel fittings commonly use ASTM A234 WPB with flanges in A105. Stainless fittings use A403 WP304/316. For sour service, specify NACE MR0175/ISO 15156 compliance. Steel Pipe Schedule Chart links pipe wall thickness to fitting selection.
Get a Quote
Tell HXSCO your requirements and we will respond with a competitive quote and lead time.
Frequently Asked Questions
Weld-neck flanges have a long tapered hub that transfers stress smoothly into the pipe, making them preferred for cyclic and high-pressure service. Slip-on flanges are easier to align and weld but are rated for lower stress applications.
ASME B16.9 covers factory-made wrought butt-welding fittings. MSS SP-75 covers high-strength wrought fittings.
Yes. We supply carbon steel A105, stainless 304/316/321, duplex 2205 and nickel alloy flanges to ASME, EN and API dimensions.
Raised face is standard for process piping and concentrates gasket load. Flat face is used on cast-equipment connections (pumps, valves) to avoid bending the flange.
Get a Quote for Fittings & Flanges
Send HXSCO your MTO with sizes, ratings, material and standard. We will quote pipes, fittings and flanges as a complete kit.