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Stainless Steel 304 Heat Exchanger Tubes (S30400)
Carried by A213 seamless, A249 welded and A688 feedwater heater tubes. The baseline 18/8 selection for fresh water, steam and mild organic duty.
Stainless Steel Heat Exchanger Tubes Manufacturer in India
MLTI Private Limited, formerly trading as Moonlight Tube Industries, is a leading manufacturer, supplier and exporter of stainless steel heat exchanger tubes operating out of Gujarat, India, with a combined annual production capacity of approximately 8,000 MT at a facility running since 2008.
An SS heat exchanger tube carries one process fluid while a second moves across its outside, so the wall is both a heat transfer surface and a pressure boundary. Seamless production follows ASTM A213 / ASME SA-213, welded production ASTM A249 / ASME SA-249, feedwater heater work ASTM A688 and general service tubing ASTM A269. Seamless lengths, pierced and cold-drawn from solid billet, carry no longitudinal weld and hold up under the higher pressures and temperatures of refinery and power service. Welded lengths, rolled from strip and continuously fused, then cold-worked and annealed, hold tighter wall tolerance at lower cost across large bundles. Both routes finish bright annealed and eddy-current tested before dispatch. Eleven grades run here: 304, 304L, 310, 316, 316L, 316Ti, 321, 321H, 347, 347H and 904L, matched against UNS callouts such as S31603, S32109 and N08904. Chromium from 16.0 to 26.0% against nickel from 8.0 to 28.0% sets corrosion and temperature behaviour across the list.
Standard austenitic grades certify 515 MPa tensile strength, 205 MPa yield strength and 35% elongation, the low-carbon pair 485 MPa and 170 MPa. Refinery, chemical, power and food-plant exchangers take the output. We hold ISO 14001 and 45001 certifications. Each lot releases on an EN 10204 3.1 mill test certificate against BIS, EIL, IBR and PED 2014/68/EU approvals.
Stainless Steel Heat Exchanger Tube Specifications
SS Heat exchanger tube material specifications, standards, route, dimensional envelope and delivery condition are set out in the table below.
| Parameter | Value |
|---|---|
| Grades | 304, 304L, 310, 316, 316L, 316Ti, 321, 321H, 347, 347H, 904L |
| Applicable standards | ASTM A213 / ASME SA-213 (Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes) ASTM A249 / ASME SA-249 (Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes) ASTM A688 (Seamless and Welded Austenitic Stainless Steel Feedwater Heater Tubes) ASTM A269 (Seamless and Welded Austenitic Stainless Steel Tubing for General Service) |
| Manufacturing route | Seamless; welded (ERW) |
| Outside diameter | 10.30 mm (NB 6) to 273.10 mm (NB 250) |
| Wall thickness | 1.24 mm (Sch-5S) to 12.70 mm (Sch-80S) |
| Configuration | Straight lengths; U-bends formed to drawing |
| Length | Cut to the ordered figure |
| Delivery condition | Solution annealed and pickled |
| Tube ends | Square cut and deburred for roller expansion or seal welding |
Heat Exchanger Tubes Material and Grade Selection
Grade selection on an exchanger is governed by the more aggressive of the two media. The eleven grades we roll are listed in the table below against the tube specifications that carry each one.
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SS 304L Heat Exchanger Tubes (S30403)
The same three specifications as 304. Carbon is capped at 0.035% max in the seamless (SA-213) and feedwater heater (SA-688) specifications and 0.030% max in the welded specification (SA-249), which protects the heat-affected zone where tube ends stay unannealed after rolling and welding.
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310 SS Heat Exchanger Tubes (S31000)
A 25Cr–20Ni austenitic grade offering excellent oxidation and scaling resistance up to ~1150°C, ideal for high-temperature heat exchanger service.
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Heat Exchanger SS 316 Tubes (S31600)
Listed in A213, A249 and A688. Two to three % molybdenum lifts pitting resistance where chlorides concentrate against the tube wall under deposits.
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SS Heat Exchanger 316L Tubes (S31603)
Carried by the same three specifications. The default for welded process exchangers since low carbon holds intergranular resistance through the longitudinal seam.
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Type 316Ti Heat Exchanger Tubes (S31635)
TP316Ti is listed in ASTM A213 / ASME SA-213 for seamless tube; it is not a grade of ASTM A249 / ASME SA-249, so the welded route is not available under that specification. Titanium stabilisation suits cyclic hot-process service.
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321 SS Heat Exchanger Tubes (S32100)
A213 and A249 both list it. Titanium stabilisation blocks chromium carbide precipitation above 425°C on the hot end of a process circuit.
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Heat Exchanger SS 321H Tubes (S32109)
A213 and A249 carry the H grade. Carbon held between 0.04 and 0.10% delivers the creep-rupture allowables that code-governed design calls for.
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Stainless Steel 347 Heat Exchanger Tubes (S34700)
Listed in A213 and A249. Niobium survives the welding arc where titanium does not, so stabilisation carries through into the joint. Niobium-bearing weld metal is more prone to hot cracking than 321, so weld procedure control matters in heavier walls.
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Type 347H Heat Exchanger Tubes (S34709)
A213 and A249 both carry it. Creep-rated 347 for high-temperature process circuits needing elevated-temperature stress values from the design code.
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SS 904L Heat Exchanger Tubes (N08904)
N08904 is listed in ASTM A213 / ASME SA-213 for seamless tube. and ASTM A249 for welded tube, and in ASTM A269 for general-service tube. Copper-bearing, for dilute sulphuric acid and reducing conditions.
Grade Selection Criteria
Treat the tube side and shell side as separate corrosion problems and specify whichever is worse. Chloride concentration, metal temperature and pH decide the molybdenum requirement: 304 to 316 to 904L as the duty hardens. Metal temperature above 425°C determines whether a stabilised or H grade is needed, independent of the chloride question. Seamless A213 and welded A249 carry the same grade chemistry, so that choice is one of wall tolerance, cost and end-user preference rather than corrosion.
Heat Exchanger Tube Forms and Types
We produce heat exchanger tubing in seamless sizes from 3.2 mm to 127 mm OD or welded variants up to 304.8 mm OD. Industrialists select straight lengths for easy cleaning or U-bends to eliminate internal joints.
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Seamless Heat Exchanger Tubes
Seamless heat exchanger tubes are pierced from a solid billet and finished hot or cold as specified on the order, leaving no longitudinal joint. ASTM A213 / ASME SA-213 usually covers this route from 3.2 mm inside diameter to 127 mm outside diameter on walls of 0.4 mm to 12.7 mm; other diameters are supplied where they meet every other requirement of the specification.
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Welded (ERW) Heat Exchanger Tubes
Welded heat exchanger tubing starts as a solution-annealed strip, roll-formed and fused along one seam without filler metal. ASTM A249 / ASME SA-249 usually covers this route from 3.2 mm inside diameter to 304.8 mm outside diameter on walls of 0.4 mm to 8.1 mm; other dimensions are supplied where they meet every other requirement of the specification.
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U-Bend Heat Exchanger Tubes
U-bend heat exchanger tubes remove a joint from inside the bundle and let each tube expand independently of the shell. Send the bend radius, both leg lengths and the tangent, and state whether the bend is re-annealed.
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Straight-Length Heat Exchanger Tubes
Straight tube suits fixed-tubesheet and floating-head layouts, where both ends land in a tubesheet, and the bore stays mechanically cleanable. Ends are squared and deburred so the tube rolls in cleanly.
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Stainless Steel Shell and Tube Heat Exchanger
In a shell-and-tube exchanger, a bundle of tubes sits inside a cylindrical shell. One fluid flows through the tubes, and the other flows around them inside the shell, so heat crosses the tube wall without the two streams mixing. We supply the tube for these bundles in straight lengths and U-bends.
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Stainless Steel Tube Coil Heat Exchanger
A tube coil heat exchanger uses a helically coiled tube, which packs a long flow path into a small volume and raises the heat transfer coefficient on both sides. It suits compact units where space is limited. Corrosion resistance and bore finish come from the base tube, the grade, the solution anneal and the pickle, not from the coiling. We supply the plain base tube; the coiling is done downstream.
Industrial Applications of Stainless Steel Heat Exchanger Tubes
Stainless steel heat exchanger tubes serve critical cooling, heating, and processing functions across major industries requiring reliable corrosion resistance and thermal performance.
Oil Refining and Petrochemical Processing
Crude preheat trains, reboilers, overhead coolers and interstage exchangers run hydrocarbon against hydrocarbon or cooling water. Stainless steel shell and tube heat exchangers on chloride-bearing streams take 316L, and stabilised 321 or 347 is specified for the hotter reformer circuits.
Chemical and Fertiliser Plant
Reactor jackets, evaporator bodies, acid coolers and urea circuits attack the tube from the process side rather than the water side. Grade 904L is specified for dilute sulphuric acid; 316L covers organic and mild mineral acid duty.
Power Generation
Closed feedwater heaters, lube-oil coolers, generator hydrogen coolers and auxiliary exchangers draw on the same tube. ASTM A688 governs the feedwater heater case in 304, 304L, 316 and 316L, U-tubes included, between 15.9 mm and 25.4 mm outside diameter.
Food, Beverage and Dairy Processing
Pasteurisers, wort coolers, evaporators and edible-oil heaters see caustic and acid on every clean-in-place cycle, and the passive film rebuilds afterwards. Stainless steel tube heat exchangers on product duty are specified in 304 or 316L.
Pharmaceutical and Fine Chemical Manufacturing
Jacketed reactors, solvent coolers and purified-water circuits need a stainless steel heat exchange tube that won't shed corrosion debris into the product. Low-carbon 316L is the usual answer because expanded joints stay free of grain-boundary chromium carbide.
Desalination and Water Treatment
Brine heaters, effluent coolers and reverse osmosis skids meet the chloride limit above the tube-side limit for 304. Two grades cover it: 316L at moderate loads, 904L where chloride and temperature climb together.
Design Considerations and Failure Modes in Heat Exchanger Tubing
Two mechanical failure modes account for a large share of bundle damage, and neither is a tube fault. Differential expansion between shell and bundle loads fixed-tubesheet units, so a U-tube or floating-head layout is chosen where the temperature difference is large. Fretting at baffle holes and flow-induced vibration attack unsupported spans. The tube-to-tubesheet joint sets a wall constraint of its own: metal has to be there to roll into the groove, so the thinnest gauge isn't always right. Enhanced-surface work sits outside our mill. Finned tube and coil exchangers both start from a plain base tube, and that base tube is what we roll.
Shipping and Packaging of SS Heat-Exchanger Tubes
As a trusted supplier, we enforce strict packaging standards to ensure tube bundles arrive safely and undamaged.
- Tubes are strapped into hexagonal bundles by diameter and gauge, then timber-cased where the destination calls for it.
- U-bends ship in crates with both legs supported.
- Plastic end plugs and sleeving fit where the order calls for it.
- Bundle tags carry heat number, grade, specification and size.
- An EN 10204 3.1 mill test certificate releases each lot.
- Export consignments move FOB or CFR to Brazil, Vietnam, Turkey and Europe.
Why Buy SS Heat Exchanger Tubes From MLTI?
Buyers return to Moonlight Tubes for certified material, approved grades and stock that ships on schedule. Every order is backed by documented quality, a wide size range and delivery commitments we hold to.
Quality Certification
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IBR & EIL Approved
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Why
Choose Us
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Wide Range of Grades & Sizes
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Timely Global Delivery
SS Heat Exchanger Tubes: FAQs
Seamless heat exchanger tubes are manufactured to ASTM A213 / ASME SA-213, and welded tubes to ASTM A249 / ASME SA-249. Feedwater heater tube falls under ASTM A688, general service tubing under ASTM A269.
Specify against the more aggressive of the two fluids. Grade 304 covers fresh water and steam, 316L handles chlorides and mild acids, stabilised 321, 321H, 347 and 347H hold temperatures above 425°C, and 904L suits dilute sulphuric acid.
Seamless heat exchanger tubes are drawn from a pierced billet and carry no seam. Welded tubes are formed from strips and fused along one seam, giving a truer wall and lower cost per metre at larger diameters.
Yes. U-bend heat exchanger tubes are formed to drawing from our own finished straight tube. Supply the bend radius, both leg lengths, the tangent and the grade, and state whether the bent leg is re-annealed.