1. What is 904L Stainless Steel?
904L stainless steel (UNS N08904/EN 1.4539) is an ultra-low carbon, high-alloy austenitic stainless steel. Its core advantage is its extremely strong corrosion resistance in harsh environments such as dilute sulfuric acid and chloride-containing media, and it is also easy to process and weld.
2. Freeman Valve's 904L stainless steel ANSI Y type strainer has the following advantages:
2.1 Excellent Corrosion Resistance:
a. Freeman Valve's 904L stainless steel ANSI Y type strainer has high molybdenum (Mo: 4~5%) and copper (Cu: 1~2%) content, which significantly improves their resistance to reducing acids (such as sulfuric acid and phosphoric acid) and halides (such as chloride ions);
b. Freeman Valve's 904L stainless steel ANSI Y type strainer perform excellently in media such as dilute sulfuric acid, boiling phosphoric acid, and organic acids, exhibiting outstanding resistance to pitting and crevice corrosion.
2.2 Excellent resistance to stress corrosion cracking (SCC): Freeman Valve's 904L stainless steel ANSI Y type strainer is suitable for environments containing chloride ions (such as seawater and chloride solutions), exhibiting superior resistance to stress corrosion cracking compared to conventional austenitic stainless steels.
2.3 High-temperature adaptability: Freeman Valve's 904L stainless steel ANSI Y type strainer maintain stability at high temperatures and can withstand short-term environments up to approximately 400°C.
3. The following issues should be noted when using 904L stainless steel ANSI Y type strainer:
3.1 Not suitable for strong oxidizing environments: In strong oxidizing acids such as nitric acid, the corrosion resistance of 904L stainless steel ANSI Y type strainer is actually inferior to that of 304L or 316L ANSI Y type strainer with lower molybdenum content.
3.2 Sensitivity issues: Improper welding or heat treatment can easily lead to carbide precipitation, requiring solution treatment (rapid cooling at 1100~1150°C) to restore performance.
4. Classic Applications of Freeman Valve's 904L Stainless Steel ANSI Y type strainer:
4.1 Freeman Valve's 904L stainless steel ANSI Y type strainer is widely used in sulfuric acid environments. Examples include: dilute sulfuric acid storage tanks, pipelines, and heat exchangers (especially for sulfuric acid concentrations ≤10%, exhibiting excellent corrosion resistance at temperatures ≤40℃).
4.2 Freeman Valve's 904L stainless steel ANSI Y type strainer is widely used in chloride-containing systems. Examples include: seawater cooling systems, salt chemical evaporators, and chlorination reactor linings.
4.3 Freeman Valve's 904L stainless steel ANSI Y type strainer is widely used in organic acid processing. Examples include: acetic acid and formic acid production equipment, preventing localized corrosion.
4.4 Freeman Valve's 904L stainless steel ANSI Y type strainer is widely used in environmental protection and hydrometallurgical fields. Examples include: flue gas desulfurization (FGD) system components and acidic wastewater treatment equipment.
4.5 Freeman Valve's 904L stainless steel ANSI Y type strainer is widely used in PTA (purified terephthalic acid) production. For example: crystallizers and condensers used in high-temperature acetic acid media.
4.6 Freeman Valve's 904L stainless steel ANSI Y type strainer is widely used in the pharmaceutical industry. For example: reaction vessels and pipelines for high-purity pharmaceuticals (resistant to cleaning agent corrosion).
Differences between 904L and 2205 stainless steel ANSI Y type strainer in resisting chloride ion corrosion
1. Different emphasis on pitting/crevice corrosion resistance:
1.1 The pitting equivalent value (PREN≈33-35) of 2205 ANSI Y type strainer is higher than that of 904L ANSI Y type strainer (PREN≈32-34), and the strengthening effect of nitrogen makes it more resistant to pitting corrosion in high-concentration, high-temperature chloride ion environments (such as high-chlorinated brine in deep well oil production, seawater above 60℃).
1.2 The high nickel + copper content of 904L ANSI Y type strainer results in a passivation film stability far exceeding that of 2205 in chloride-containing reducing media (such as dilute sulfuric acid + chloride ion mixed systems), and avoids the phase imbalance problem of duplex steel. 2. Differences in Stress Corrosion Cracking (SCC) Resistance:
2.1 Stress corrosion cracking under chloride ion conditions is a common failure mode for austenitic stainless steel 2205 ANSI Y type strainer, but the high nickel content of 904L ANSI Y type strainer significantly reduces this susceptibility. 2205 ANSI Y type strainer also exhibit better SCC resistance than ordinary austenitic steels such as 316L, but under the same chloride ion concentration and stress conditions, their long-term stability is slightly lower than that of 904L ANSI Y type strainer.
3. Differences in Process and Operating Condition Matching:
3.1 904L ANSI Y type strainer require no heat treatment after welding and has good low-temperature toughness, making them suitable for polar and marine environments.
3.2 2205 ANSI Y type strainer require controlled heat input during welding to avoid excessive ferrite content, but their high strength (tensile strength ≥620MPa, more than 1.2 times that of 904L ANSI Y type strainer) makes them more suitable for high-pressure + high-chlorine composite operating conditions (such as high-pressure seawater pipelines).
Design Standard of 904L Y Type Strainer:
Design Acc. to ASME B16.34 (ANSI Standard 904L Y Type Strainer);
Design Acc. to EN-12516-1/2 (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer).
Test Standard of 904L Y Type Strainer:
Test Acc. to API 598 (ANSI Standard 904L Y Type Strainer);
Test Acc. to EN 12266-1/2 (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer).
Surface Finishing of 904L Y Type Strainer:
All 904L Y Type Strainer surface is finely machined to achieve the required roughness and conforms to standard MSS SP-110.
Size of 904L Y Type Strainer:
From DN1/4’’ to 48’’ (ANSI Standard 904L Y Type Strainer);
From DN8 to DN1200 (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer).
Face to Face of 904L Y Type Strainer:
Face to Face Acc. to ASME B16.10 (ANSI Standard 904L Y Type Strainer);
Face to Face Acc. to EN 558-1 (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer).
Pressure Rating of 904L Y Type Strainer:
ANSI Class 150 904L Y Type Strainer (ANSI Standard 904L Y Type Strainer);
ANSI Class 300 904L Y Type Strainer (ANSI Standard 904L Y Type Strainer);
ANSI Class 600 904L Y Type Strainer (ANSI Standard 904L Y Type Strainer);
ANSI Class 800 904L Y Type Strainer (ANSI Standard 904L Y Type Strainer);
ANSI Class 900 904L Y Type Strainer (ANSI Standard 904L Y Type Strainer);
ANSI Class 1500 904L Y Type Strainer (ANSI Standard 904L Y Type Strainer);
ANSI Class 2500 904L Y Type Strainer (ANSI Standard 904L Y Type Strainer);
EN 1092 PN 16 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer);
EN 1092 PN 25 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer);
EN 1092 PN 40 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer);
EN 1092 PN 63 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer);
EN 1092 PN 100 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer);
EN 1092 PN 160 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer);
EN 1092 PN 250 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer);
EN 1092 PN 320 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer);
EN 1092 PN 400 904L Y Type Strainer (EN Standard 904L Y Type Strainer, DIN Standard 904L Y Type Strainer).
Working Temperature of 904L Y Type Strainer:
Please refer to the "Temperature and Pressure Curve of 904L Y Type Strainer" for temperature and pressure changes.
Ends Connection of 904L Y Type Strainer:
ANSI Flange Ends 904L Y Type Strainer;
ANSI Integral Flange Ends 904L Y Type Strainer;
ANSI Welded Flange Ends 904L Y Type Strainer;
Butt Weld (ASME B16.25) Ends 904L Y Type Strainer;
Butt Weld x ANSI Flange Ends 904L Y Type Strainer;
EN 1092 Flange Ends 904L Y Type Strainer;
EN 1092 Integral Flange Ends 904L Y Type Strainer;
EN 1092 Welded Flange Ends 904L Y Type Strainer;
Butt Weld (EN 12627) Ends 904L Y Type Strainer;
Butt Weld (ISO 1127) Ends 904L Y Type Strainer;
Butt Weld x EN 1092 Flange Ends 904L Y Type Strainer;
Male NPT (ASME B1.20.1) Ends 904L Y Type Strainer;
Male BSPP (ISO 228-1) Ends 904L Y Type Strainer;
Male BSPT (ISO 7-1) Ends 904L Y Type Strainer;
Male NPT x Female NPT Ends 904L Y Type Strainer;
Male BSPP x Female BSPP Ends 904L Y Type Strainer;
Male BSPT x Female BSPT Ends 904L Y Type Strainer;
Male NPT x Long Butt Weld (+100 mm) Ends 904L Y Type Strainer;
Male BSPP x Long Butt Weld (+100 mm) Ends 904L Y Type Strainer;
Male BSPT x Long Butt Weld (+100 mm) Ends 904L Y Type Strainer;
Female NPT (ASME B1.20.1) Ends 904L Y Type Strainer;
Female BSPP (ISO 228-1) Ends 904L Y Type Strainer;
Female BSPT (ISO 7-1) Ends 904L Y Type Strainer;
Socket Weld (ASME B16.11) Ends 904L Y Type Strainer;
Socket Weld (EN 12760) Ends 904L Y Type Strainer;
Female NPT x Socket Weld Ends 904L Y Type Strainer;
Female BSPP x Socket Weld Ends 904L Y Type Strainer;
Female BSPT x Socket Weld Ends 904L Y Type Strainer;
Butt Weld (ASME B16.25) Ends 904L Y Type Strainer;
Butt Weld (EN 12627) Ends 904L Y Type Strainer;
Female NPT x Butt Weld Ends 904L Y Type Strainer;
Female BSPP x Butt Weld Ends 904L Y Type Strainer;
Female BSPT x Butt Weld Ends 904L Y Type Strainer;
Female NPT x Long Butt Weld (+100 mm) Ends 904L Y Type Strainer;
Female BSPP x Long Butt Weld (+100 mm) Ends 904L Y Type Strainer;
Female BSPT x Long Butt Weld (+100 mm) Ends 904L Y Type Strainer;
Long Butt Weld (+100 mm Weld Stub) Ends 904L Y Type Strainer.
CE Marking of 904L Y Type Strainer:
CE Marking is Available to 904L Y Type Strainer with a Diameter of DN32 or Larger.
Chemical Composition of 904L Y Type Strainer:
For the Chemical Composition of 904L Y Type Strainer, please refer to EN 10204 Type 3.1 certificate.
Mechanical Properties of 904L Y Type Strainer:
For the Mechanical Properties of 904L Y Type Strainer, please refer to EN 10204 Type 3.1 certificate.
Certificate of 904L Y Type Strainer:
All 904L Y Type Strainer will be delivered with EN 10204 Type 3.1 Certificate.
Approvals of 904L Y Type Strainer:
MSS SP-110 Certified of 904L Y Type Strainer;
NACE MR 0175 Certified of 904L Y Type Strainer
API 607 Fire Safe Certified of 904L Y Type Strainer;
ISO 9001 Certified of 904L Y Type Strainer;
PED Certified of 904L Y Type Strainer.
Available Upon Request of 904L Y Type Strainer:
NACE MR0175 is available upon request of 904L Y Type Strainer;
ATEX is available upon request of 904L Y Type Strainer;
TA-LUFT is available upon request of 904L Y Type Strainer;
SIL is available upon request of 904L Y Type Strainer;
Degreasing is available upon request of 904L Y Type Strainer;
Fire Safe is available upon request of 904L Y Type Strainer;
Stem Extension is available upon request of 904L Y Type Strainer;
Double Block and Bleed is available upon request of 904L Y Type Strainer.