Custom-made stainless steel tubing coil

A custom-made stainless steel tubing coil is a length of stainless steel tube precisely wound, bent, or formed into a helical, spiral, or conical shape to serve as a heat exchanger, fluid conduit, or gas flow element inside a compact envelope. Smartclima Co., Ltd. manufactures these coils to your exact specifications in our own factory in Ningbo, China, with no minimum order and worldwide shipping. Whether you need a single prototype helical coil heat exchanger for a lab rig or a production run of tube coil heat exchangers for a commercial refrigeration line, our engineering team builds each coil to your drawings, your material grade, and your pressure rating.

We work with stainless steel grades 304, 304L, 316, and 316L, covering outer diameters from 3 mm to 50 mm (1/8″ to 2″) and wall thicknesses from 0.5 mm to 3 mm. Every coil is pressure tested and leak tested before it leaves our facility. This page explains what a stainless steel tubing coil is, how we fabricate it, the technical specifications we can meet, and how to request a quote for your project.

TL;DR: Smartclima custom-manufactures stainless steel tubing coils in grades 304/304L/316/316L to your exact dimensions, with no minimum order, full pressure and leak testing, and worldwide shipping. Send us your drawings or specs for a no-obligation quote.

What Is a Stainless Steel Tubing Coil?

A stainless steel tubing coil is a continuous length of stainless steel tube that has been formed into a coiled geometry rather than left straight. The coil shape packs a large surface area into a small volume, which is why these components are so widely used in heat transfer applications. A straight tube offers limited contact area with the surrounding fluid or gas, but the same length wound into a coil multiplies that surface area many times over within the same footprint.

The purpose of coil tubing falls into three broad categories:

• Heat transfer: The coil is immersed in, or surrounded by, a fluid at a different temperature. Heat moves through the tube wall between the fluid inside the coil and the fluid outside it. This is the working principle behind every tube coil heat exchanger, from immersion chillers in brewing tanks to condenser coils in commercial refrigeration.
• Fluid conveyance: A coil can carry a liquid or gas from one point to another while accommodating thermal expansion, vibration, or spatial constraints that a rigid straight pipe cannot handle. Hydraulic and pneumatic line coils in heavy machinery are a common example.
• Gas flow and pressure regulation: In process systems, coiled tubing can serve as a flow restrictor, a pulsation dampener, or a compact reservoir that smooths pressure fluctuations in a gas line.

Coil geometry varies by application. A helical coil winds the tube around a central axis in a spring-like spiral, producing a cylindrical coil with a consistent diameter and pitch. A spiral or flat coil winds the tube in a single plane, like a clock spring, producing a flat pancake shape that fits into shallow tanks or narrow vessels. A conical coil winds the tube with a progressively changing diameter, producing a cone shape that can match the internal profile of a tapered vessel. Each style has distinct heat transfer and flow characteristics, and the right choice depends on the vessel geometry, the required surface area, and the available space.

Why Stainless Steel for Custom Coil Heat Exchangers?

Stainless steel is the most commonly specified material for custom coil heat exchangers because it combines corrosion resistance, mechanical strength, hygienic properties, and temperature tolerance in a single alloy family. Carbon steel coils rust in damp or saline environments. Copper coils corrode when exposed to ammonia, certain acids, or high-velocity fluids. Stainless steel resists all of these, and it does so while maintaining structural integrity at both cryogenic and elevated temperatures.

Smartclima fabricates coils from four primary grades:

Grade	Key Property	Best Application
304	General-purpose austenitic stainless steel, good corrosion resistance, excellent formability and weldability	HVAC coils, food and beverage heat exchangers, general fluid conveyance, brewing and distilling
304L	Low-carbon variant of 304, reduced carbide precipitation during welding, improved weld zone corrosion resistance	Welded coil assemblies, applications requiring extensive orbital welding, sanitary welds
316	Added molybdenum (2 to 3%), superior resistance to pitting and crevice corrosion, especially in chloride environments	Marine and saltwater coils, chemical process heat exchangers, medical gas lines, pharmaceutical
316L	Low-carbon variant of 316, combines the chloride resistance of 316 with improved weldability	Welded marine coils, offshore and coastal installations, high-purity process systems

The choice between 304 and 316 comes down to the operating environment. If the coil will contact chlorides, saltwater, brine, or certain acids, 316 or 316L is the correct choice. For most freshwater, food-grade, and general HVAC applications, 304 or 304L provides excellent performance at a lower material cost. The L grades (304L and 316L) are specified when the coil design requires significant welding, because the reduced carbon content minimizes carbide precipitation at the weld boundaries, which in turn preserves corrosion resistance in the heat-affected zone.

Stainless steel also offers hygienic properties that make it the standard material in food, beverage, and pharmaceutical processing. The smooth, non-porous surface does not harbor bacteria, is easy to clean and sterilize, and does not impart taste or odor to the product it contacts. For a deeper look at how we form stainless steel and other metals into coils and bends, see our bend metallic tubing page, which covers the bending process for stainless steel, copper, and other tube materials.

Our Workshop & Manufacturing Capabilities

Precision coil fabrication requires controlled machinery, not manual bending around a mandrel by hand. Our factory in Ningbo is equipped with the following equipment for custom stainless steel tubing coil production:

• CNC coil winding machines: Computer-controlled winding ensures repeatable accuracy in coil diameter, pitch, and total number of turns. Once a program is set, every coil in the production run comes out identical, which is critical for OEM customers who need consistency across batches.
• CNC tube bending machines: These machines use specialized tooling and dies to form tubes into complex bend geometries, including tight-radius bends, multi-plane bends, and compound shapes that cannot be produced by simple winding alone. They maintain consistent wall thickness and cross-section throughout the bend, avoiding the flattening or wrinkling that hand-bending produces.
• Automatic orbital welding: For coils that require welded joints, inlet or outlet fittings, or multi-section assembly, orbital welding delivers clean, consistent, full-penetration welds with minimal heat input. This is especially important for sanitary and high-purity applications where weld quality directly affects corrosion resistance and cleanability.
• Full testing and inspection station: Every coil undergoes pressure testing, leak detection, and dimensional verification before it is approved for shipment. We test to your specified working pressure and confirm that the coil holds pressure without leakage.

The Fabrication Process, Step by Step

1. Material selection and verification: We confirm the stainless steel grade, tube OD, wall thickness, and temper (annealed for coiling) against your specification. Material certificates are available on request.
2. Tube preparation: The tube is cut to the calculated straight length required to produce the finished coil geometry, accounting for the bend allowance and any straight lead-in or lead-out sections.
3. CNC coil winding or bending: The tube is loaded onto the CNC winding or bending machine and formed to the programmed coil diameter, pitch, and number of turns. For complex geometries, this may involve multiple setups or a combination of winding and bending operations.
4. Welding and fitting attachment: If the design calls for welded fittings, flanges, or multi-section assembly, orbital welding is performed at this stage. Welds are cleaned and passivated where required.
5. Surface finishing: The coil can be supplied in pickled, polished, or bright-annealed finish depending on your application requirements.
6. Pressure testing and leak detection: The finished coil is pressurized to the specified test pressure and inspected for leaks. Dimensional verification confirms that the coil diameter, pitch, overall height, and connection positions match the drawing.
7. Cleaning, packaging, and shipping: The coil is cleaned, protected against transit damage, and packed for shipment to your destination.

Coil Styles We Can Fabricate

We produce three primary coil geometries, each suited to different vessel shapes and heat transfer requirements:

Coil Style	Typical Dimensions	Common Applications
Helical coil	Cylindrical, coil OD 50 mm to 800 mm, pitch 5 mm to 200 mm, 2 to 50 turns	Immersion heat exchangers in tanks and vessels, HVAC condenser and evaporator coils, brewing and distilling, chemical reactor heating or cooling
Spiral (flat pancake) coil	Flat, coil OD 100 mm to 600 mm, pitch 5 mm to 50 mm, 3 to 30 turns	Shallow tank immersion, Dutch tub and wood fired hot tub heaters, space-constrained installations, flat heat exchanger plates
Conical coil	Tapered, large end OD 200 mm to 600 mm, small end OD 50 mm to 300 mm, 3 to 20 turns	Tapered or conical vessels, matching internal vessel profiles, specialized heat transfer where flow area changes along the coil length

For a specific example of a single-coil heat exchanger with both tube ends on the same side, see our custom stainless steel single coil heat exchanger, which illustrates one common helical configuration. If your application involves a wood fired or Dutch tub heater, our stainless steel coil heat exchanger for Dutch tub and wood fired hot tub heater coil kit pages show complete kits built around spiral stainless steel coils.

Technical Specifications

The table below summarizes the standard range we can fabricate. If your requirements fall outside these ranges, contact us with your specifications and our engineering team will evaluate feasibility.

Parameter	Range
Material grades	304, 304L, 316, 316L
Outer diameter (OD)	3 mm to 50 mm (1/8″ to 2″)
Wall thickness	0.5 mm to 3 mm (0.020″ to 0.118″)
Coil diameter	50 mm to 800 mm (2″ to 31.5″)
Pitch (turn spacing)	5 mm to 200 mm (0.2″ to 7.9″)
Maximum tube length	Up to 30 m (100 ft) in a single continuous coil
Number of turns	2 to 50 turns (style dependent)
Surface finish	Pickled, polished (240 to 600 grit), bright annealed
Connection types	Flared ends, welded fittings, threaded fittings, flanged ends, custom fittings to drawing
Pressure rating	Tested to your specified working pressure, typically up to 10 MPa (1,450 psi) for standard wall thicknesses
Temper	Annealed (soft) for coiling, or half-hard where specified
Certification	Material test certificates (MTC) available on request

What You Need to Provide for a Perfect Custom Coil

To fabricate your coil correctly the first time, we need three categories of information. The more detail you provide, the more accurate our quote and the faster our production.

1. Tubing Specifications

• Material grade: 304, 304L, 316, or 316L. If you are unsure which grade suits your application, tell us the operating environment and we will recommend one.
• Outer diameter (OD): Specify in millimeters or inches. Both metric and imperial dimensions are accepted.
• Wall thickness: Specify in millimeters or inches (gauge numbers are also acceptable).
• Total tube length: The straight length of tubing required before coiling, if known. If you do not know this, we can calculate it from the coil geometry.

2. Coil Geometry Requirements

• Coil style: Helical, spiral (flat), or conical. If you are unsure, describe the vessel or space the coil will occupy.
• Coil diameter: Specify whether the dimension is inner diameter (ID) or outer diameter (OD).
• Pitch: The center-to-center distance between adjacent turns. For tight-pitch coils, specify the gap between turns instead if that is what your design requires.
• Overall height or width: The finished envelope of the coil, which determines how many turns fit.
• Inlet and outlet connection positions: Where the tube ends should emerge from the coil and in what orientation.

3. Application Details

• Intended use: Heat transfer, fluid transport, gas flow, or other.
• Operating pressure and temperature: The normal operating range and any peak or design pressure the coil must withstand.
• Connection types: Flared, welded, threaded, flanged, or custom.
• Fluid or gas inside the coil and outside it: This affects material grade selection and surface finish requirements.

Drawings, sketches, or even photographs of an existing coil or the vessel it will fit into are extremely helpful. Our engineering team can work from CAD files, hand drawings, or dimensional notes. If you have only a concept and no drawing, we can help develop the specification from your description.

Applications Across Industries

Custom stainless steel tubing coils serve a wide range of industries. The following are the most common applications we fabricate for:

• HVAC and refrigeration coils: Condenser and evaporator coils, immersion heat exchangers for chillers and process cooling, and refrigerant line coils. These coils must withstand refrigerant pressures and repeated thermal cycling. See our HVAC heat exchangers category for related products.
• Hydraulic and pneumatic line coils: Flexible fluid power conduits in heavy machinery, construction equipment, and mobile hydraulics. The coil accommodates movement and vibration while maintaining pressure integrity.
• Medical gas line coils: Fabricated to high-purity standards for hospital and laboratory gas distribution systems. 316L is typically specified for its corrosion resistance and weld quality.
• Process industry coils: Used in chemical reactors, heat exchangers, and fuel lines where material integrity is critical. Grade 316 is common for chloride-containing process fluids.
• Food and beverage: Brewing, distilling, dairy, and food processing applications where hygienic, food-grade stainless steel is required. Immersion chilling and heating coils in fermentation tanks are a frequent request. Our copper tube coil immersion heat exchanger page covers a copper alternative for applications where copper is preferred.
• Marine and saltwater: Coils for desalination, marine cooling, offshore platforms, and saltwater aquarium systems. Grade 316 or 316L is essential for chloride resistance. For extreme corrosion environments, our titanium tube coil heat exchanger offers even higher resistance.
• Wood fired hot tub and pool heating: Spiral coils that use thermosiphon circulation to heat water without electricity. These are a core product line for Smartclima, and our coil designs are patent-protected.

For a broader view of our tube coil heat exchanger offerings, browse the tube coil heat exchanger category, which includes stainless steel, copper, and titanium coil variants.

Custom Manufacturing and OEM Service

Smartclima operates as a custom manufacturer, not a stock distributor. This means every coil is built to order according to your specifications. The process is designed to support both one-off prototype projects and ongoing OEM production:

• Rapid prototyping: We accept orders of a single unit. If you are developing a new product and need a prototype coil to test, we can fabricate one to your drawings without requiring a production minimum. This lets you validate your design before committing to a production run.
• OEM production: For established products, we produce coils in batch quantities to your fixed specification. Once a coil design is approved, we retain the CNC programs and tooling setup so that repeat orders produce identical coils with no re-engineering required.
• End-to-end project management: From your initial inquiry through quoting, fabrication, testing, and shipping, you work with a single point of contact. We handle material sourcing, fabrication, quality control, export documentation, and logistics.
• Design collaboration: If you have a functional requirement but no finished drawing, our engineering team can help develop the coil specification. We can advise on material grade selection, coil geometry, pressure rating, and connection types based on your application.

Our custom stainless steel tubing coil product page provides additional detail on the custom fabrication process for stainless steel coils specifically.

Worldwide Shipping and Regional Availability

Smartclima has served over 10,000 customers worldwide since 2001. We ship custom stainless steel tubing coils to every major region:

• North America: United States, Canada, and Mexico. Free or flat-rate shipping to most US and Canadian destinations, with typical lead times of 7 to 15 days for production plus 5 to 10 days for shipping.
• Europe: United Kingdom, European Union (Germany, France, Netherlands, Italy, Spain, and others). We handle export documentation and customs paperwork.
• Middle East: UAE, Saudi Arabia, Qatar, Kuwait, Oman, and other Gulf states.
• South Asia: Pakistan, India, Bangladesh, and Sri Lanka. We have strong visibility in South Asian markets and are familiar with local import requirements.
• Australia and New Zealand: Free shipping available for many coil products.
• Southeast Asia: Singapore, Malaysia, Thailand, Vietnam, Indonesia, Philippines.
• Africa: South Africa, Nigeria, Kenya, Egypt, and other African destinations.
• South America: Brazil, Chile, Argentina, Colombia, and others.

Typical production lead time for a custom coil is 7 to 15 working days, depending on complexity and material availability. Shipping time varies by destination and shipping method. Contact us with your location and we will provide a specific shipping quote and estimated delivery time.

Why Choose Smartclima?

• 20+ years of manufacturing experience: Founded in 2001, Smartclima has over two decades of experience in HVAC parts and custom metal fabrication. Learn more on our About Us page.
• 10,000+ customers served worldwide: Our customer base spans every continent and includes HVAC technicians, procurement managers, engineers, and factory buyers.
• Own factory in Ningbo, China: We manufacture in our own facility, not through subcontractors. This gives us direct control over quality, lead time, and cost.
• Quality control on every coil: Every stainless steel tubing coil we produce is pressure tested and leak tested before shipment. Dimensional verification confirms that the coil matches your drawing.
• No minimum order: We accept orders of a single unit. Prototype coils, one-off replacements, and small production runs are all welcome.
• Worldwide shipping: We ship to North America, Europe, the Middle East, South Asia, Australia, Southeast Asia, Africa, and South America.
• 30-day returns: If a coil does not meet your specification, contact us within 30 days to arrange a return or replacement.

Frequently Asked Questions

Contact Us to Custom-Make Your Stainless Steel Tubing Coil

Ready to get started? Send us your drawings, specifications, or application details and our engineering team will provide a no-obligation quote for your custom stainless steel tubing coil. We respond to inquiries within one business day and can advise on material grade selection, coil geometry, and connection types if you need engineering input.

Contact us today to discuss your project. Whether you need a single prototype coil or an ongoing OEM production run, Smartclima will fabricate it to your exact specification, pressure test it, and ship it to your door.