Duplex and Super Duplex Stainless Steel Polyurethane Insulated Pressure Vessels
Duplex and super duplex stainless steel polyurethane insulated pressure vessels combine the exceptional strength and corrosion resistance of two-phase stainless steels with the thermal efficiency of polyurethane foam insulation. These vessels feature a microstructure of approximately equal amounts of austenite and ferrite phases, providing superior mechanical properties and resistance to stress corrosion cracking.
Why Choose Duplex and Super Duplex Stainless Steel for Polyurethane Insulated Pressure Vessels?
Duplex and super duplex stainless steels are essential for aggressive chloride environments where standard austenitic stainless steels are susceptible to stress corrosion cracking. Their high strength allows reduced wall thickness compared to austenitic grades, providing cost savings for thick-wall vessels while delivering superior corrosion performance.
Duplex and Super Duplex Stainless Steel Polyurethane Insulated Pressure Vessel Applications
Common applications include:
- Offshore oil and gas equipment
- Seawater handling systems
- Chemical processing with chlorides
- Pulp and paper digesters
- Desalination equipment
- Geothermal applications
Duplex and Super Duplex Stainless Steel Specifications and Characteristics
At Roben, Mfg, Inc., we offer comprehensive options including:
- 2205 Duplex (UNS S31803/S32205)
- 2507 Super Duplex (UNS S32750)
- Zeron 100 Super Duplex (UNS S32760)
- Ferralium 255 (UNS S32550)
- Solution annealing required
Certifications and Standards
Our polyurethane insulated pressure vessels are designed and manufactured in accordance with stringent industry standards:
- ASME Section VIII Division 1 & 2: Pressure vessel design and fabrication standards
- ASME Section IX: Welding procedures and qualifications
- NBIC: National Board Inspection Code compliance
- CRN: Canadian Registration Number for Canadian installations
- PED: Pressure Equipment Directive for European Union market
- U Stamp & R Stamp: ASME certification for new construction and repairs
Duplex and Super Duplex Stainless Steel Polyurethane Insulated Pressure Vessel FAQs
What is the difference between duplex and super duplex stainless steel?
Super duplex grades contain higher chromium, molybdenum, and nitrogen content, providing superior pitting and crevice corrosion resistance. Super duplex has a PREN (Pitting Resistance Equivalent Number) above 40, compared to approximately 35 for standard duplex 2205. Super duplex is specified for more aggressive chloride environments.
What are the fabrication considerations for duplex stainless steel vessels?
Duplex steels require careful control of heat input during welding to maintain the proper austenite-ferrite balance. Maximum interpass temperatures must be observed, and solution annealing may be required for heavy sections. Ferrite content testing is performed to verify proper microstructure after fabrication.
What temperature limits apply to duplex stainless steel?
Duplex stainless steels are limited to approximately 600°F maximum service temperature due to the formation of embrittling phases at elevated temperatures. Minimum service temperature is typically -50°F. This temperature range is well-suited for polyurethane insulation applications.
Contact Roben, Mfg, Inc.
For more information about our polyurethane insulated pressure vessel solutions or to request a quote, please contact Roben, Mfg, Inc. today. Our experienced engineering team is ready to assist you in developing the perfect solution for your unique application requirements.
Phone: (732) 364-6000 | Email: sales@robenmfg.com
760 Vassar Ave, Lakewood, NJ 08701
