904L Tubing for Chemical Processing

904L Tubing for Chemical Processing: The Corrosion-Resistant Solution

In the chemical processing industry, where equipment is exposed to sulfuric acid, hydrochloric acid, and chloride-bearing solutions, material selection is critical. 904L stainless steel tubing, also known as UNS N08904 or EN 1.4539, provides exceptional corrosion resistance in these aggressive environments.

This article explains why 904L tubing is a preferred choice for chemical plants, compares international standards, and highlights key applications.

What Is 904L Tubing?

904L tubing is made from a super austenitic stainless steel that contains:

24–26% Nickel

4–5% Molybdenum

1.2–2% Copper

Low carbon content (≤ 0.02%)

This unique composition gives 904L tubing superior resistance to:

Sulfuric acid (H₂SO₄)

Phosphoric acid (H₃PO₄)

Hydrochloric acid (HCl)

Chloride-induced pitting and crevice corrosion

Stress corrosion cracking (SCC)

904L Tubing Specifications

Property	Value
UNS	N08904
EN Number	1.4539
ASTM Standards	B677 (Seamless), B673 (Welded), B674 (Welded Tube)
DIN / EN Standards	EN 10216-5 (Seamless), EN 10217-7 (Welded)
JIS Equivalent	SUS 890L
Delivery Condition	Solution Annealed (Bright Annealed / Pickled)
Form	Seamless or Welded Tubes (Straight or U-bend)

904L Tubing vs Other Stainless Steel Grades

Grade	Pitting Resistance	Sulfuric Acid Resistance	Cost
316L	Moderate	Poor	Low
317L	Good	Fair	Medium
904L	Excellent	Excellent	High
Alloy 20	Excellent	Excellent	Higher

 

For chemical processing environments where acids, chlorides, and high temperatures are common, 904L tubing delivers long-term corrosion resistance, mechanical reliability, and cost-effective performance over time.

Whether you're designing a new sulfuric acid system or upgrading corroded lines in a fertilizer plant, ASTM B677 and EN 1.4539 904L tubes are a dependable choice.