904L is an ultra-low carbon, high-alloy austenitic stainless steel. The core advantage of 904L check valves is their exceptional corrosion resistance in harsh environments such as dilute sulfuric acid and chloride-containing media, and their ease of machining and welding.
① Freeman Valve's 904L check valves have high molybdenum (Mo: 4~5%) and copper (Cu: 1~2%) content, significantly improving their resistance to reducing acids (such as sulfuric acid and phosphoric acid) and halides (such as chloride ions);
② Freeman Valve's 904L check valves perform excellently in media such as dilute sulfuric acid, boiling phosphoric acid, and organic acids, exhibiting outstanding resistance to pitting and crevice corrosion.
Freeman Valve's 904L check valves are 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.
Freeman Valve's 904L check valves maintain stability at high temperatures and can withstand short-term environments up to approximately 400°C.
In strong oxidizing acids such as nitric acid, 904L check valves actually have lower corrosion resistance than 304L or 316L valves with lower molybdenum content.
Improper welding or heat treatment of 904L check valves can easily lead to carbide precipitation, requiring solution treatment (rapid cooling at 1100~1150°C) to restore performance.
For example: dilute sulfuric acid storage tanks, pipelines, heat exchangers (especially for sulfuric acid with a concentration ≤10%, exhibiting excellent corrosion resistance at temperatures ≤40℃).
For example: seawater cooling systems, salt chemical evaporators, chlorination reactor linings.
For example: acetic acid and formic acid production equipment, preventing localized corrosion.
For example: flue gas desulfurization (FGD) system components, acidic wastewater treatment equipment.
For example: crystallizers and condensers used in high-temperature acetic acid media.
For example: reaction vessels and pipelines for high-purity pharmaceuticals (resistant to cleaning agent corrosion).
① The pitting equivalent value (PREN≈33-35) of the 2205 check valves is higher than that of the 904L check valves (PREN≈32-34), and the nitrogen content further enhances its resistance to pitting corrosion in high-concentration, high-temperature chloride ion environments (such as high-chlorinated brine in deep well oil production and seawater above 60℃).
② The high nickel + copper content of the 904L check valves results in a passivation film with significantly greater stability than that of the 2205 check valves in reducing media containing chloride (such as dilute sulfuric acid + chloride ion mixtures), without exhibiting the phase imbalance problem common in duplex steels.
① Stress corrosion cracking under chloride ion conditions is a common failure mode for 2205 check valves, but the high nickel content of 904L check valves significantly reduces this susceptibility. 2205 check valves also exhibit better SCC resistance than ordinary austenitic steels such as 316L check valves, but under the same chloride ion concentration and stress conditions, their long-term stability is slightly lower than that of 904L check valves.
① 904L check valves require no heat treatment after welding and have good low-temperature toughness, making them suitable for polar and marine environments.
② 2205 check valves 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 check valves) makes them more suitable for high-pressure + high-chlorine composite operating conditions (such as high-pressure seawater pipelines).
Design Standard of 904L Wafer Check Valve:
Design Acc. to ASME B16.34 (ANSI Standard 904L Wafer Check Valve);
Design Acc. to EN-12516-1/2 (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve).
Test Standard of 904L Wafer Check Valve:
Test Acc. to API 598 (ANSI Standard 904L Wafer Check Valve);
Test Acc. to EN 12266-1/2 (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve).
Surface Finishing of 904L Wafer Check Valve:
All 904L Wafer Check Valve surface is finely machined to achieve the required roughness and conforms to standard MSS SP-110.
Size of 904L Wafer Check Valve:
From DN1/4’’ to 48’’ (ANSI Standard 904L Wafer Check Valve);
From DN8 to DN1200 (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve).
Face to Face of 904L Wafer Check Valve:
Face to Face Acc. to ASME B16.10 (ANSI Standard 904L Wafer Check Valve);
Face to Face Acc. to EN 558-1 (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve).
Pressure Rating of 904L Wafer Check Valve:
ANSI Class 150 904L Wafer Check Valve (ANSI Standard 904L Wafer Check Valve);
ANSI Class 300 904L Wafer Check Valve (ANSI Standard 904L Wafer Check Valve);
ANSI Class 600 904L Wafer Check Valve (ANSI Standard 904L Wafer Check Valve);
ANSI Class 800 904L Wafer Check Valve (ANSI Standard 904L Wafer Check Valve);
ANSI Class 900 904L Wafer Check Valve (ANSI Standard 904L Wafer Check Valve);
ANSI Class 1500 904L Wafer Check Valve (ANSI Standard 904L Wafer Check Valve);
ANSI Class 2500 904L Wafer Check Valve (ANSI Standard 904L Wafer Check Valve);
EN 1092 PN 16 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve);
EN 1092 PN 25 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve);
EN 1092 PN 40 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve);
EN 1092 PN 63 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve);
EN 1092 PN 100 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve);
EN 1092 PN 160 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve);
EN 1092 PN 250 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve);
EN 1092 PN 320 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve);
EN 1092 PN 400 904L Wafer Check Valve (EN Standard 904L Wafer Check Valve, DIN Standard 904L Wafer Check Valve).
Working Temperature of 904L Wafer Check Valve:
Please refer to the "Temperature and Pressure Curve of 904L Wafer Check Valve" for temperature and pressure changes.
Ends Connection of 904L Wafer Check Valve:
ANSI Flange Ends 904L Wafer Check Valve;
ANSI Integral Flange Ends 904L Wafer Check Valve;
ANSI Welded Flange Ends 904L Wafer Check Valve;
Butt Weld (ASME B16.25) Ends 904L Wafer Check Valve;
Butt Weld x ANSI Flange Ends 904L Wafer Check Valve;
EN 1092 Flange Ends 904L Wafer Check Valve;
EN 1092 Integral Flange Ends 904L Wafer Check Valve;
EN 1092 Welded Flange Ends 904L Wafer Check Valve;
Butt Weld (EN 12627) Ends 904L Wafer Check Valve;
Butt Weld (ISO 1127) Ends 904L Wafer Check Valve;
Butt Weld x EN 1092 Flange Ends 904L Wafer Check Valve;
Male NPT (ASME B1.20.1) Ends 904L Wafer Check Valve;
Male BSPP (ISO 228-1) Ends 904L Wafer Check Valve;
Male BSPT (ISO 7-1) Ends 904L Wafer Check Valve;
Male NPT x Female NPT Ends 904L Wafer Check Valve;
Male BSPP x Female BSPP Ends 904L Wafer Check Valve;
Male BSPT x Female BSPT Ends 904L Wafer Check Valve;
Male NPT x Long Butt Weld (+100 mm) Ends 904L Wafer Check Valve;
Male BSPP x Long Butt Weld (+100 mm) Ends 904L Wafer Check Valve;
Male BSPT x Long Butt Weld (+100 mm) Ends 904L Wafer Check Valve;
Female NPT (ASME B1.20.1) Ends 904L Wafer Check Valve;
Female BSPP (ISO 228-1) Ends 904L Wafer Check Valve;
Female BSPT (ISO 7-1) Ends 904L Wafer Check Valve;
Socket Weld (ASME B16.11) Ends 904L Wafer Check Valve;
Socket Weld (EN 12760) Ends 904L Wafer Check Valve;
Female NPT x Socket Weld Ends 904L Wafer Check Valve;
Female BSPP x Socket Weld Ends 904L Wafer Check Valve;
Female BSPT x Socket Weld Ends 904L Wafer Check Valve;
Butt Weld (ASME B16.25) Ends 904L Wafer Check Valve;
Butt Weld (EN 12627) Ends 904L Wafer Check Valve;
Female NPT x Butt Weld Ends 904L Wafer Check Valve;
Female BSPP x Butt Weld Ends 904L Wafer Check Valve;
Female BSPT x Butt Weld Ends 904L Wafer Check Valve;
Female NPT x Long Butt Weld (+100 mm) Ends 904L Wafer Check Valve;
Female BSPP x Long Butt Weld (+100 mm) Ends 904L Wafer Check Valve;
Female BSPT x Long Butt Weld (+100 mm) Ends 904L Wafer Check Valve;
Long Butt Weld (+100 mm Weld Stub) Ends 904L Wafer Check Valve.
CE Marking of 904L Wafer Check Valve:
CE Marking is Available to 904L Wafer Check Valve with a Diameter of DN32 or Larger.
Chemical Composition of 904L Wafer Check Valve:
For the Chemical Composition of 904L Wafer Check Valve, please refer to EN 10204 Type 3.1 certificate.
Mechanical Properties of 904L Wafer Check Valve:
For the Mechanical Properties of 904L Wafer Check Valve, please refer to EN 10204 Type 3.1 certificate.
Certificate of 904L Wafer Check Valve:
All 904L Wafer Check Valve will be delivered with EN 10204 Type 3.1 Certificate.
Approvals of 904L Wafer Check Valve:
MSS SP-110 Certified of 904L Wafer Check Valve;
NACE MR 0175 Certified of 904L Wafer Check Valve
API 607 Fire Safe Certified of 904L Wafer Check Valve;
ISO 9001 Certified of 904L Wafer Check Valve;
PED Certified of 904L Wafer Check Valve.
Available Upon Request of 904L Wafer Check Valve:
NACE MR0175 is available upon request of 904L Wafer Check Valve;
ATEX is available upon request of 904L Wafer Check Valve;
TA-LUFT is available upon request of 904L Wafer Check Valve;
SIL is available upon request of 904L Wafer Check Valve;
Degreasing is available upon request of 904L Wafer Check Valve;
Fire Safe is available upon request of 904L Wafer Check Valve;
Stem Extension is available upon request of 904L Wafer Check Valve;
Double Block and Bleed is available upon request of 904L Wafer Check Valve.