Power Generation
Main Steam, Reheat, and Balance of Plant
Power plant flange supply across coal, gas, nuclear, and combined-cycle service. F91 and F92 on main steam, F347 on auxiliary, AWWA on raw water intake.
Main steam and hot reheat headers run in F91 modified 9 chromium-moly at temperatures from 1050 to 1200 degrees F. Welding consumables and procedures are tightly controlled. F92 with tungsten substitution extends service into ultra-supercritical units.
Auxiliary and balance of plant service uses F347 stabilized austenitic for high-temperature steam and F316L for condensate and feedwater service. Carbon A105 handles utility air, instrument air, and lower-temperature service.
Raw water intake and circulating water lines move into AWWA C207 plate-cut territory at the larger diameters. Class D or Class E covers most intake pressures. The intake station may have AIS compliance requirements if the utility is federally funded.
Common Standards
- ASME B16.5
- ASME B16.47
- AWWA C207 on raw water
- ASME Section III for nuclear
Common Materials
- F91
- F92
- F347
- F316L
- A105
- A516-70