SS 304L Pipe Fittings are produced of a low-carbon form of the austenitic stainless steel and the carbon content is not exceeded at 0.03-percent. This single metallurgical difference provides three important performance benefits upon which procurement engineers and project specifiers count: no sensitization, at weld heat-affected locations, no post-weld heat treatment (PWHT), and can be used in the as-welded state. In the case of pharmaceutical manufacturing and food and beverage processing, cryogenic service, chemical processing and marine engineering, the use of SS 304L Pipe Fittings instead of standard 304 provides a significant risk point in the welded piping systems and shortens fabrication time and cost.
In Metinox Overseas, we are distributing SS 304L Pipe Fittings which are produced in total accordance with ASTM A403 WP304L which includes UNS S30403 (American) and DIN 1.4307 (European) equivalent description. We have a complete line in all standard fittings types ranging as far as elbows and tees all the way to reducer, stub ends, caps and crosses in sizes of 1/2 NB through to 48 NB and schedules of SCH 5S up to XXS. In order we provide EN 10204 3.1 mill test certificates and inspection reports of third party. Visit our parent category for the complete range:View all Stainless Steel Pipes and Tubes.
Request a quote now!The technical justification of the choice of SS 304L Pipe Fittings is the content of carbon. Standard SS 304 permits carbon to 0.08% maximum. The heat of welding 304 causes the carbon to flow to the grain boundaries and forms chromium carbides with chromium, a condition referred to as sensitization. The sensitized areas lose their resistance to corrosion and are susceptible to intergranular attack under corrosive conditions.
SS 304L, which contains 0.03 percent of carbon, does not form sensitization in the welding process. It implies that SS 304L Pipe Fittings are applicable in the as-welded state in corrosive service without any post-weld annealing or heat treatment. In the case of fabrication shops and project sites, this translates into a faster turnaround, reduced cost and equal performance than treated 304 assemblies.
Three reasons engineers specify SS 304L Pipe Fittings:
The concept of the term dual certified 304/304L is quite often a source of confusion in procurement. A vast number of SS 304L Pipe Fittings are manufactured using a chemistry that is in fact conforming to both 304 and 304L standards. Low carbon chemistry of 304L and controlled addition of nitrogen enables the material to satisfy the increased minimum yield strength demand of 304. This would imply that one heat of material could be test certified to both grades at the same time. The Dual-certified SS 304L Pipe Fittings provide flexibility to the fabricators without the drawback on no-sensitization characteristic of the L grade in welded service.
Review the key differences between SS 304 and SS 304L Pipe Fittings to select the right grade for your project.
| Property | SS 304 Pipe Fittings | SS 304L Pipe Fittings |
|---|---|---|
| Carbon Content Max | 0.08% | 0.03% max (key differentiator) |
| UNS Designation | S30400 | S30403 |
| DIN Equivalent | 1.4301 | 1.4307 |
| Sensitization Risk | Present at weld heat-affected zones | None: immune from sensitization |
| Post-Weld Heat Treatment | May be required in corrosive service | Not required |
| As-Welded Condition Use | Restricted in aggressive environments | Fully suitable even in severe conditions |
| Dual Certification Possible | Not applicable | Yes: 304/304L dual certified available |
| Preferred Applications | General purpose industrial piping | Pharma, food, cryogenic, chemical, marine welded assemblies |
| ASTM Standard | ASTM A403 WP304 | ASTM A403 WP304L |
Also see:SS 304 Pipe Fittings (Standard Grade) for comparison.
| Specification Parameter | Detail |
|---|---|
| ASTM Standard | ASTM A403 WP304L |
| UNS Number | S30403 |
| DIN / EN Equivalent | 1.4307 |
| JIS Equivalent | SUS 304L |
| Dimensional Standard | ASME B16.9 (butt weld fittings), ASME B16.11 (socket weld / threaded) |
| Size Range | 1/2" NB to 48" NB |
| Schedule / Thickness | SCH 5S, 10S, 40S, 80S, SCH 10, 40, 80, 120, 160, XXS |
| Fitting Grades | WP304L-S (Seamless), WP304L-W (Welded), WP304L-WX (Welded + X-Ray Examined) |
| Test Certificates | EN 10204 3.1 Mill Test Certificate, Third-Party Inspection available |
| Manufacturing Methods | Hot forming, cold forming, seamless extrusion, welded fabrication |
When raising a request for quotation for SS 304L Pipe Fittings, procurement engineers typically specify one of three grade suffixes under ASTM A403:
| Element | Carbon (C) | Chromium (Cr) | Nickel (Ni) | Mn | Others |
|---|---|---|---|---|---|
| Content | 0.03% max* | 18.00 to 20.00% | 8.00 to 12.00% | 2.00% max | Si 0.75% max, P 0.045% max, S 0.030% max |
*Carbon at 0.03% max is the defining characteristic of SS 304L Pipe Fittings. This low carbon level prevents sensitization and makes as-welded service possible.
| Property | SS 304L Pipe Fittings | SS 304 Pipe Fittings | Unit |
|---|---|---|---|
| Tensile Strength (Min) | 485 | 515 | MPa |
| Yield Strength 0.2% Offset (Min) | 170 | 205 | MPa |
| Elongation in 2 inches (Min) | 35% | 35% | % |
| Hardness (Rockwell B Max) | 92 | 92 | HRB |
| Density | 7.93 g/cm³ | 7.93 g/cm³ | g/cm³ |
| Standard | ASTM / UNS | DIN / EN | JIS | Common Name |
|---|---|---|---|---|
| Grade Designation | UNS S30403 | DIN 1.4307 | SUS 304L | SS 304L |
Metinox Overseas stocks and supplies the following SS 304L Pipe Fittings types. Each fitting type is available in seamless (WP-S), welded (WP-W) and welded with X-ray (WP-WX) grades as per ASTM A403 WP304L and ASME B16.9:
| SS 304L Fitting Type | Description and Common Applications |
|---|---|
| SS 304L 90 Degree LR Elbow | Long radius elbow for standard direction changes. Most common fitting in piping systems. Radius = 1.5D. |
| SS 304L 45 Degree Elbow | Used where space constraints require a shallower angle change. Common in process and HVAC systems. |
| SS 304L 180 Degree Return Bend | For full flow reversal in coil configurations, heat exchangers and chemical circulation systems. |
| SS 304L Equal Tee | All three outlets equal in size. Used for branch connections where branch flow equals main flow. |
| SS 304L Reducing Tee | Branch outlet smaller than run outlets. Ideal for secondary offtake lines in distribution headers. |
| SS 304L Concentric Reducer | Centreline-aligned size reduction. Used in vertical lines and horizontal liquid lines. |
| SS 304L Eccentric Reducer | Flat side allows drainage and prevents air pockets. Preferred in pump suction lines. |
| SS 304L End Cap | Butt-weld pipe end closure. Used to terminate dead-end pipe runs or isolate a leg. |
| SS 304L Stub End (Long and Short) | Used with lap joint flanges. Long pattern per MSS-SP-43 and short pattern available for space-constrained assemblies. |
| SS 304L Cross | Four-outlet fitting for junction points in distribution systems. Equal and reducing cross types available. |
| SS 304L 3D and 5D Bend | Radius equals 3 or 5 times pipe diameter. Used in pigging systems, slurry lines and where low-pressure-drop flow paths are required. |
| Parameter | Minimum | Maximum | Governing Standard |
|---|---|---|---|
| Nominal Bore (NB) | 1/2" (DN15) | 48" (DN1200) | ASME B16.9 |
| Wall Schedule | SCH 5S | XXS (Double Extra Strong) | ASME B36.19M |
| Common Schedules Stocked | SCH 10S | SCH 10S, 40S, 80S, 10, 40, 80 | ASME B16.9 |
| Elbow Radius Types | Short Radius (1.0D) | Long Radius (1.5D), 3D, 5D | ASME B16.9 |
The low-carbon, no-sensitization, as-welded suitability of SS 304L Pipe Fittings makes them the preferred choice across several demanding industries:
Pharmaceutical production needs piping to be purified through several cleaning and sterilization procedures. The reason why SS 304L Pipe Fittings is used is that sensitized areas of weld would be at risk of pitting and crevice corrosion under the exposure of cleaning agents, steam sterilization and sanitizing chemicals. The no-PWHT criterion also implies that fittings can be installed and brought back to work quicker during the construction and maintenance shutdowns of the plant.
Food grade piping specifications demand smooth-bore fittings that are corrosion free and that do not add contamination. SS 304L Pipe Fittings comply with FDA and European standards of food contact materials and are resistant to corrosion caused by organic acids, salt brines, cleaning-in-place chemicals and steam found in food processing plants. The fact that no carbide precipitation takes place means that the inner part of the weld areas will be non-corrosive during the entire life of the installation.
Austenitic stainless steel is tough and ductile at low temperatures, and thus SS 304L Pipe Fittings can be used in the cryogenic service of LNG, liquid nitrogen, liquid oxygen, and industrial gas storage and distribution systems. Low levels of carbon also stabilize the austenitic microstructure at low temperatures.
The piping of the chemical plants is manufactured using numerous weld joints traversing through various corrosive media. By specifying SS 304L Pipe Fittings, the necessity to anneal all joints post welding is removed, which is time consuming and in some installed systems geometrically infeasible. The UNS S30403 chemistry offers protection against nitric acid, light organic acids, alkalis and atmospheric corrosion.
Marine service exposes piping to salt-spray environments of chloride. SS 304L Pipe Fittings are used in offshore platforms and shipbuilding in freshwater, seawater cooling circuits, ballast systems, and chemical injection lines where low-carbon grade is required to offer the corrosion stability in the humid, salty operating environments.
SS 304L Pipe Fittings price per kg in India depends on the fitting type, size, wall schedule, grade suffix (WP-S, WP-W or WP-WX) and order quantity. Prices are subject to LME stainless steel surcharges, raw material costs and prevailing market conditions. Metinox Overseas offers competitive ex-works and CIF pricing for both domestic and export orders.
Request Current Price: Contact our sales team with your item list and quantity for an immediate quotation.
Metinox Overseas exports SS 304L Pipe Fittings to the following countries:
Complete your SS 304L Pipe Fittings procurement with our full range of 304L piping system components:
Also see:SS 304 Flanges andSS 304 Pipes for standard-carbon 304 alternatives.
Carbon content is the main difference. The carbon content of SS 304L Pipe Fittings is 0.03% max compared to 0.08% max in SS 304 fittings. It is a lower carbon that enables 304L to resist sensitization during welding and does not require a post-weld heat treatment, which can be utilized in the as-welded state in corrosive service. SS 304 can be subjected to PWHT in areas of concern with regard to weld zone corrosion.
Yes. A large number of SS 304L Pipe Fittings are manufactured with a low-carbon, nitrogen-assisted chemistry that satisfies the chemical needs of 304L, as well as the mechanical strength needs of 304. These fittings are dual certified and will have 304/304L on their test certificates. They offer tensile and yield strength minimums of standard 304 with the sensitization immunity of 304L.
The specification on wrought austenitic stainless steel piping fittings is ASTM A403. WP: Wrought Piping. 304L is the grade designation (UNS S30403, DIN 1.4307). The following suffix following the dash denotes method of manufacture: WP304L-S (Seamless), WP304L-W (Welded) and WP304L-WX (Welded, Radiography Examined). Your SS 304L Pipe Fittings purchase order specifying ASTM A403 WP304L will assure the right chemistry, mechanical properties and dimensional compliance to ASME B16.9.
Metinox Overseas offers SS 304L Pipe Fittings with a diameter of 1/2 inch NB to 48 inch NB and wall schedules of SCH 5S up to XXS (Double Extra Strong). The most commonly used NB sizes are SCH 10S, 40S and 80S. Ordered custom sizes and heavy wall schedules are fully certified ASTM A403 WP304L.
SS 304L Pipe Fittings find application mainly in pharmaceutical production, food and beverage production, cryogenic plant, chemical processing plants and marine engineering. The cause in each instance is the same, namely, that the low-carbon 304 chemistry removes the sensitization at welds, permits as-welded service without post-weld annealing, and offers the same corrosion resistance as the standard 304 in the entire piping system, including all weld heat-affected areas.
Metinox Overseas is a manufacturer and supplier of SS 304L Pipe Fittings in India, with exports to the UAE, Saudi Arabia, USA, UK, Singapore, South Africa and Australia. Our supply covers all types, sizes and schedules under ASTM A403 WP304L with EN 10204 3.1 mill test certificates and optional third-party inspection. Contact our sales team with your inquiry list for same-day quotation.
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