Offshore topside and subsea spools
Duplex and stainless spools for platform and splash zone duty
Topside piping has to handle chlorides, CO2, occasionally H2S and constant motion, with weight paid for in deck load. Duplex gives roughly twice the yield of 316L at better chloride resistance, which means thinner walls and lighter spools; super duplex and 825 take the worst sections.
[ 02 ] Selection
How we choose the material for this duty.
- General topside process and utility spools: duplex 2205
- Seawater, splash zone and high chloride duty: super duplex 2507
- Sour and acid service sections: Alloy 825 solid or clad
- Firewater and cooling seawater: cupro nickel 90/10
- Structural deck and support steel: S355J2+N and S690QL
Grades we would specify.
Questions buyers ask about this duty.
Why duplex rather than 316L on topsides?
Duplex 2205 has about twice the yield strength of 316L and far better chloride pitting and stress corrosion resistance. The higher strength allows a thinner wall, so the spool is lighter — and deck weight is money offshore.
Can you supply spools with the fittings and flanges matched?
Yes — pipe, butt weld fittings and flanges in the same grade with one set of certificates, so the fabricator is not chasing material from three sources.
Send the duty, not just the grade.
Tell us the service conditions, the current material and what life you are getting. Our Dubai desk comes back with the grade, the thickness and what is in stock.