How to choose: Start with the medium, concentration and service temperature. 316L contains molybdenum and usually resists pitting better than 304, but that does not mean it is automatic for seawater or every chemical duty. Duplex 2205 and 2507 also need a service-specific check — do not swap grades by “higher is better” alone. Huabo Pipe Industry Co., Ltd. (HuaboPipe) supplies fittings and flanges in all three families to order. Standard sizes DN15 to DN1200; larger sizes are made to drawing, up to DN3000. Lead time and MOQ are confirmed with the inquiry.
HuaboPipe was founded in 2004, with the company in Wenzhou. The factory is at No. 102 Longqing Road, Liandu District, Lishui, Zhejiang, and manufactures stainless steel butt-weld fittings and forged flanges. Buy to the project drawing and material spec; if the grade is still open, the design party should confirm against the duty.
304 vs 316L: How to Choose?
One-table view
| Check | 304 / 304L | 316 / 316L | Duplex 2205 |
|---|---|---|---|
| What it is | Cr-Ni austenitic | Mo-bearing; usually better vs pitting than 304 | Duplex microstructure; higher strength |
| Watch in service | Water quality, temperature, cleaning media | Chloride level, temperature, crevice risk | Corrosion duty, design strength, welding |
| Do not assume OK for | Seawater, chlorinated circulating water | Seawater, hot chloride media, unverified acids | Untested corrosive media, or thinning without calculation |
| Match the pipe | Same grade and welding requirements as the drawing | Same grade and welding requirements as the drawing | Grade, filler and WPS as specified by design |
| Huabo supply | Available to order | Available to order | Available to order |
The “L” in 304L / 316L means low carbon, which helps reduce intergranular corrosion risk after welding — it does not replace a duty and welding review. Order 304 or 304L exactly as written on the purchase documents; do not change the grade on your own.
How to decide
- Medium and temperature first, price second. Chloride risk also depends on concentration, pH, flow and crevices — not only “is there chlorine.”
- Match the drawing. Do not down-grade or mix materials without design and welding approval.
- Seawater and chlorinated cooling water are not automatic 316L. Send water analysis, temperature and operating conditions for design review. Coastal outdoor exposure is not the same duty as seawater inside the pipe.
- 2205 / 2507 also need a duty check. Do not treat duplex as a universal upgrade; grade, wall, filler and WPS must follow the project design.
- Large sizes to drawing. Standard sizes DN15 to DN1200; larger sizes are made to drawing, up to DN3000. Large flanges follow the drawing.
Related product pages:
What HuaboPipe can supply
- Grades: 304/304L, 316/316L, 310S, 321, 2205, 2507
- Products: butt-weld elbows (45°/90°/180°), tees, reducers, crosses, caps, stub ends; SO/WN/LWN/blind and non-standard blinds
- Size: standard DN15 to DN1200; larger to drawing, up to DN3000
- Dimensions: fittings to ASME B16.9; flanges to ASME B16.5 up to NPS 24 and to ASME B16.47 or drawing above; also EN, DIN, JIS or drawing
- OEM from drawings or samples
- Inspection: PMI available; hydrotest, PT/UT/RT and MTRs as agreed. Heat treatment: solution annealing. Surface treatment: polishing, pickling, sand blasting and sand tumbling.
- Lead time and MOQ: confirmed with the inquiry
For a quote, send medium, temperature, pressure, size/wall, standard, quantity, and whether you need MTRs or NDE. Email lucas@hbpipe.com or WhatsApp +86 152 1057 8298. We typically reply within one business day.
Certificates: certificate page — Special Equipment License TS2733H03-2027, ISO 9001/14001/45001, DNV, BV, PED (TÜV SÜD). Company: About. Related: 316L vs duplex 2205 fittings.
FAQ
Can 304 fittings go in circulating cooling water? Not from the label “cooling water” alone. Check chloride, dosing, concentration ratio and temperature; design confirms the grade. Switching to 316L does not automatically make it suitable.
Can 304L and 304 fittings be mixed? Buy to the drawing and material spec. Whether mixing is allowed depends on duty and welding — design must confirm.
316L or 2205? Both need medium, concentration, temperature and design pressure reviewed. If the design already specifies one grade, buy that. HuaboPipe supplies both to order.
Stock and MOQ? To order. MOQ and lead time confirmed with the inquiry.
Are large flanges catalogue items? Regular sizes follow the applicable standard. DN3000-class pieces are made to drawing, not treated as catalogue stock.
3 Comments