Coiled Tubing: Instrumentation-Grade Stainless Steel & Nickel-Alloy Tube in Continuous Coils
Coiled tubing, in the instrumentation world, means seamless or welded stainless-steel and nickel-alloy tube that comes in continuous, fully annealed coils rather than straight 20 ft lengths. That difference matters in the field. Long runs for impulse lines, sampling lines, hydraulic and pneumatic lines, and steam tracing can be made up with far fewer joints, and the tube bends to fit whatever path the installation demands.
On this page, "coiled tubing" refers to instrumentation-grade stainless-steel and nickel-alloy tube supplied in continuous annealed coils for tube-fitting installations. It isn't oilfield well-intervention (downhole) coiled tubing run by coiled-tubing units, and it isn't soft copper or plastic coil either. Crestflo supplies coiled tube for instrumentation and industrial fluid and gas systems, matched to the compression tube fittings that seat it.
Crestflo builds both the coil and the fittings that cap it off, so the tube, ferrule and fitting are designed from the start to work together as one leak-tight system. No guesswork, no mismatched parts. Each coil leaves the factory heat-number marked, and it's backed by an EN 10204 3.1 material test certificate. Standard items sit in stock and ship right away; specials are made to order, with delivery running 6-8 weeks.
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Coiled Tubing Also Known As: Coiled Tube, SS Tube Coil & Instrument Tubing Coil
Buyers and specifiers reach for a lot of different names when they call out this product. You'll see it listed as stainless steel coiled tubing, coiled stainless steel tubing, stainless steel tube coil, stainless steel tubing coil, SS tubing coil, coiled tube, instrument tubing coil, instrumentation tubing coil, coiled instrument tubing, annealed tubing coil, or just tube in coils. Process gives it another set of labels: seamless coiled tubing or welded coil tubing. Material does the same job, only differently: 316 coiled tubing, 316L coiled tubing, 304/304L coiled tubing, 904L coiled tubing, Monel coiled tubing, Inconel coiled tubing, Alloy 825 coiled tubing. Different names, same family of product. It's all governed by ASTM A269 / A269M.
What Is Instrumentation Coiled Tubing and Why Supply It on a Coil?
Coiled tubing for instrumentation work comes as one continuous length wound onto a spool, so installers pull off what they need and bend it into place instead of piecing together short straight sections. On long impulse lines, analyzer loops and tracing circuits, that continuous supply eliminates intermediate connections. Fewer joints means fewer potential leak paths. It also lets the installer work around obstructions using nothing more than a hand or bench tube bender.
Manufacturers supply the tube fully annealed, the standard temper called for under ASTM A269. That's the temper that lets the tube coil and bend without cracking. Once installed, it seats in single- and double-ferrule compression fittings just as straight tube would, as long as the OD, wall thickness, hardness and surface finish stay within spec.
Coiled Tubing Materials: 316/316L, 304/304L, 904L, Monel, Inconel & Hastelloy
Crestflo stocks coiled tube in stainless, super-austenitic, duplex, nickel-alloy and titanium grades, with stainless as the core offering. It also carries corrosion-resistant alloy (CRA) breadth that most marketplace sellers simply don't stock. UNS designations below are standard published values. Grade metallurgy, composition and PREN details live on the linked material pages.
| Grade | UNS | Key attribute | Material page |
|---|---|---|---|
| 304 / 304L | S30400 / S30403 | General-purpose austenitic stainless | 304/304L stainless |
| 316 / 316L | S31600 / S31603 | Molybdenum-bearing, chloride-resistant workhorse | 316/316L stainless |
| 904L | N08904 | Super-austenitic, high sulfuric-acid resistance | 904L super-austenitic |
| Duplex 2205 | S32205 | Duplex, high strength + chloride SCC resistance | nickel-alloy & CRA tubing |
| Super Duplex 2507 | S32750 | Super-duplex, severe chloride service | nickel-alloy & CRA tubing |
| Monel 400 | N04400 | Nickel-copper, seawater & HF service | Monel 400 tubing |
| Inconel 625 | N06625 | Nickel-chromium, high-temp & corrosion | Inconel 625 tubing |
| Incoloy / Inconel 825 | N08825 | Nickel-iron-chromium, acid & sour service | Inconel/Incoloy 825 |
| Hastelloy C-276 | N10276 | Nickel-molybdenum-chromium, wet-chlorine | Hastelloy C-276 |
| Titanium Gr2 | R50400 | Light, excellent chloride/seawater resistance | Titanium Gr2 |
We can also supply additional grades on request: 254 SMO, AL-6XN, Alloy 20, Inconel 600/601/718, Incoloy 800/800H, Monel K500, Hastelloy C-22/B-2/B-3/X and Nickel 200/201. Given the US scope, coiled tube comes only in stainless and alloy, not brass, copper or aluminum.
Coiled Tubing Sizes: OD (1/8″–1″ & 6–12 mm), Wall & Coil Length
Coiled tube comes in both imperial and metric outside diameters across the full instrumentation range, in standard wall thicknesses. The figures below are the standard published instrument-tube dimensions per ASTM A269. They can be customized to requirement, and the complete OD × wall × working-pressure data sits on the tube OD, wall & pressure size chart, maintained by Crestflo.
| OD (in) | OD (mm) | Typical walls (in) | Temper | Coil length | Availability |
|---|---|---|---|---|---|
| 1/8″ | 3 mm | 0.028 | Fully annealed | To order | Standard / RFQ |
| 1/4″ | 6 mm | 0.028 / 0.035 | Fully annealed | To order | Standard / RFQ |
| 3/8″ | 8 / 10 mm | 0.035 / 0.049 | Fully annealed | To order | Standard / RFQ |
| 1/2″ | 12 mm | 0.035 / 0.049 / 0.065 | Fully annealed | To order | Standard / RFQ |
| 5/8″ | — | 0.049 / 0.065 | Fully annealed | To order | Standard / RFQ |
| 3/4″ | — | 0.049 / 0.065 | Fully annealed | To order | Standard / RFQ |
| 1″ | — | 0.065 / 0.083 | Fully annealed | To order | Standard / RFQ |
We supply continuous coil lengths cut to your specified run; dimensional tolerances hold to ASTM A269. Values follow the applicable standard, though we'll customize to your requirement. Just specify OD, wall thickness and coil length on the RFQ.
Seamless vs. Welded Coiled Tubing: When Each Applies
Crestflo offers coiled tube in seamless and welded construction. Seamless tube has no longitudinal weld, and engineers specify it when joint-free integrity matters most. Welded tube is drawn and bright-annealed. It's typically easier to source and less costly in the common instrument sizes, and it holds up fine across most general-service lines. Both types are furnished to ASTM A269 in the annealed condition.
| Attribute | Seamless coiled tube | Welded coiled tube |
|---|---|---|
| Wall integrity | No longitudinal seam | Autogenous weld, drawn & annealed |
| Typical cost | Higher | Lower |
| Availability | Selective sizes/grades | Broad in common sizes |
| Standard | ASTM A269 | ASTM A269 |
| Typical use | Highest-integrity / high-pressure lines | General instrument & tracing lines |
Explore the straight-length equivalents: seamless instrument tubing and welded stainless tubing.
Temper, Finish & Cleanliness: Annealed, Passivated, Electropolished & O2-Clean
Coiled tube ships fully annealed. That's the soft, ductile condition it needs to wind onto a coil and bend cleanly around a standard tube bender at the correct OD and wall. Surface options run from a mill or bright-annealed finish through passivation to electropolishing, which suits high-purity and analyzer service. When a line carries oxygen, or must meet ultra-high-purity cleanliness, oxygen / UHP cleaning covers that need. Standard high-purity electropolish targets, ≤10 µin Ra per SEMI/ASME BPE practice for example, can be set by the customer. State your required Ra and cleanliness class on the RFQ. For details, see electropolished (EP) tubing and oxygen / UHP cleaning.
Coiled Tubing Standards & Compliance: ASTM A269, A213 & NACE MR0175
We manufacture coiled instrument tube to the applicable industry standards. On this page, we state that by conformance rather than by certificate number. Crestflo holds ISO 9001 / 14001 / 45001 & PED certification, and the certificates themselves sit in the quality library.
| Standard | Scope | Applies to coiled tube |
|---|---|---|
| ASTM A269 / A269M | Seamless & welded austenitic stainless tube, general service | Primary specification |
| ASTM A213 / A213M | Seamless boiler, superheater & heat-exchanger tube | Where HX/boiler grade specified |
| NACE MR0175 / ISO 15156 | Materials for sour (H2S) service | Sour-service orders |
| EN 10204 3.1 / 3.2 | Material test certificate types | 3.1 standard; 3.2 on request |
Acceptance testing, whether hydrostatic or eddy-current, and dimensional tolerances follow ASTM A269. Every order comes with in-house PMI (positive material identification) and NDT support. Destructive testing happens at ISO/IEC 17025-accredited laboratories; third-party inspection is available on request. Crestflo marks heat and lot numbers on every coil, giving full heat-number traceability & MTC.
Tube Fittings That Seat the Coil: One Engineered System
A coil is only as reliable as the fitting gripping it. Crestflo makes the matching compression tube fittings for it, single and double ferrule, hardened and non-hardened, so the tube OD, ferrule and fitting are dimensionally matched and pull-tested together as one assembly. These fittings are performance-qualified to ASTM F1387, the standard for compression tube fittings, and that's what gives you a documented basis for dimensional interchange with major brands. Need a drop-in comparison against your current line? Request your Swagelok®/Parker® cross-reference from our engineering team. Take a look at the matching compression tube fittings and nut-and-ferrule sets.
Coiled Tubing Applications: Impulse, Analyzer, Hydraulic, Instrument-Air & Steam-Tracing Lines
Crestflo's instrumentation coiled tube carries the fluid and gas lines that instruments rely on: impulse lines to transmitters, analyzer and sampling systems, hydraulic power and control circuits, instrument-air distribution, and steam-tracing tracer runs. Coil supply wins out wherever runs stretch long, routing gets irregular, or cutting down on joints actually matters. You can browse every form on the instrumentation tubing hub, and check the stainless steel & alloy tubing range while you're at it.
Ordering Coiled Tubing: RFQ Spec Checklist
Crestflo works to RFQ, there's no live pricing available. Fill in the fields below, and the engineering team will get back to you with a quote or a sample coil. Datasheets and CAD files are available to customers on request.
| Spec field | Example | Notes |
|---|---|---|
| Material grade | 316L | Stainless, duplex or nickel alloy |
| OD | 1/2″ or 12 mm | Imperial or metric |
| Wall thickness | 0.049″ | Per ASTM A269 |
| Coil length | Specify run length | Continuous coil |
| Temper | Fully annealed | Standard deliverable |
| Finish / cleanliness | Passivated / EP / O2-clean | State Ra & class if UHP |
| Standard / MTC | ASTM A269, EN 10204 3.1 | 3.2 on request |
| Sour service | NACE MR0175 (Y/N) | If H2S present |
| Quantity | — | Per line item |
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Why Buy Coiled Tubing from Crestflo
Crestflo's the instrumentation division of a four-decade-old export house recognized by the Government of India, with a proven delivery record across the Middle East. It now serves US buyers directly. As a US-serving manufacturer, coil and matching fittings are engineered for US drop-in, with a 6-8 week lead time against the 20-plus weeks typical of the majors. Standard-item stock is ready. Specials are made to order. Every coil carries a heat number and an EN 10204 3.1 MTC, ships in both imperial and metric sizes, and spans grades from stainless through high-nickel and CRA. Indian origin; US / European melt available on request, with full material traceability. Small MOQs and private-label coil supply are on offer, alongside our 6-8 week lead time and US origin & TAA note. Reach US sales at sales@crestflousa.com or +1 346 594 9005 (Houston, TX). We Engineer Confidence.
Coiled Tubing FAQ
Is "coiled tubing" here the same as oilfield coiled tubing?
Coiled tubing sold here is instrumentation-grade stainless-steel and nickel-alloy tube, supplied in annealed coils for tube-fitting fluid and gas lines. It's not the continuous downhole tubing that oilfield coiled-tubing units run for well intervention, drilling, or workover. Crestflo doesn't make that.
Is Crestflo coiled tubing seamless or welded?
Both. Crestflo supplies seamless coiled tube where joint-free integrity is the priority, and it offers welded coiled tube where availability and cost make more sense. Both come fully annealed to ASTM A269. Check the seamless and welded tubing pages for the specifics.
What standard is coiled tubing made to?
General-service austenitic stainless tube runs primarily on ASTM A269 / A269M. Where heat-exchanger or boiler grade is called for, ASTM A213 takes over instead. Sour (H2S) service falls under NACE MR0175 / ISO 15156. Values follow whichever standard applies, and they're adjustable to the requirement.
Which materials are available as coiled tube?
We work in 304/304L, 316/316L and 904L stainless, plus duplex 2205 and super duplex 2507. Monel 400, Inconel 625, Incoloy 825, Hastelloy C-276 and Titanium Gr2 round out the list, and we'll source other nickel and CRA grades on request. Stainless and alloy only. No brass, copper or aluminum.
What sizes and coil lengths are available?
Imperial ODs run from 1/8″ to 1″; metric sizes span 3 mm to 12 mm. Standard wall thicknesses include 0.028″, 0.035″, 0.049″ and 0.065″, all manufactured per ASTM A269. Coils ship continuous, cut to whatever run length you need. You'll find the complete dimensional and pressure data on Crestflo's tubing size chart.
Will the coil seat in my Swagelok or Parker fittings?
Crestflo builds compression fittings that match ASTM F1387 performance qualifications, matching your original tube, ferrule and fitting as one dimensionally correct system. Want your part-number cross-reference? Just ask our engineering team. Swagelok® and Parker® remain trademarks of their respective owners.
Is the tube annealed, and can I bend it in the field?
Yes. Coiled tube ships fully annealed, which is the standard coilable, bendable condition called out in ASTM A269. That's what lets it be routed and bent right in the field, provided you're using a tube bender sized correctly to the OD and wall.
Do coils come with a material test certificate?
Yes. An EN 10204 3.1 material test certificate is standard (3.2 on request), and the heat/lot number is marked on every coil. See traceability.
Can you supply electropolished or oxygen-clean coils?
Yes. Crestflo offers passivation, electropolishing and oxygen / UHP cleaning. Just specify your Ra target and cleanliness class on the RFQ. Details are here: electropolished tubing and oxygen / UHP cleaning.
Is coiled tubing made in the USA?
No. Crestflo serves the US market, and while the origin is Indian, US or European melt can be arranged on request, with full material traceability behind it. The coil itself is built for a US drop-in fit, and lead time runs 6-8 weeks. For details, see the US origin & TAA note.
What is the minimum order, and do you private-label?
Small minimum order quantities are available, and Crestflo offers private-label coil supply to distributors and OEMs. See private label.
How do I get a price for coiled tubing?
Crestflo doesn't post live pricing; it works strictly to RFQ. Give them the material, OD, wall, coil length, finish and quantity, and you'll get back a quote or a sample coil through the quote request.