Instrumentation Tubing & Fittings Manufacturer for EPC, Power Plant & Process Control

✅ Professional Instrumentation Tubing & Fittings Manufacturer in China
We are a professional manufacturer of instrumentation tubing and fittings for EPC projects, power plants, petrochemical, oil & gas, water treatment, and process control systems. Instrumentation tubing is small-diameter seamless or welded tube used to connect instruments, transmitters, and sampling points to the process. Instrumentation fittings — including compression tube fittings (single and double ferrule) and ASME B16.11 forged socket weld / threaded fittings — provide leak-tight, repeatedly remakable connections without welding in many applications. Our product portfolio includes 316/316L seamless instrumentation tubing to ASTM A269 / A213, double ferrule tube fittings, single ferrule tube fittings, and ASME B16.11 forged fittings in 3000# / 6000# / 9000# classes. All products comply with ASME B16.11, ASTM A269, ASTM A213, ASME B1.20.1 (NPT), and ASME B31.3, with pressure ratings up to 15,000 psi (1,034 bar) for 1/4" 316SS double ferrule connections and temperature capability from -198°C to +537°C depending on material and configuration.

📋 Product Overview & Key Features

Instrumentation tubing and fittings form the critical link between the process and measurement/control instruments. The system must deliver leak-tight performance under pressure, vibration, and thermal cycling, while allowing repeated make-and-break for calibration and maintenance. Our products are manufactured from bar stock, billet, or seamless tube, with AISI 316/316L stainless steel as the standard material and Alloy 625, Monel 400, and Alloy 825 available for corrosive or high-integrity service. Key features include:

📦 Product Range: Tubing, Fittings & Connection Types

🔹 Instrumentation Tubing (ASTM A269 / A213)

🔹 Compression Tube Fittings (Single & Double Ferrule)

🔹 ASME B16.11 Forged Fittings (Socket Weld & Threaded)

* ASME B16.11 covers NPS 1/8 to NPS 4; most piping specifications limit socket weld fittings to NPS 2 and threaded fittings to NPS 1.5. Materials: ASTM A105 (CS), A182 F304/F316 (SS), A350 LF2 (low-temp CS), A182 F11/F22 (alloy), A182 F51 (duplex).

🔹 Fitting Configurations Available

📋 Technical Specification

* Custom materials, sizes, wall thicknesses, and fitting configurations are available upon request for EPC project tenders.

📊 Instrumentation Fitting Selection Guide

❓ Frequently Asked Questions (FAQ)

Q1: What are instrumentation tubing and fittings?
A: Instrumentation tubing is small-diameter seamless or welded tube used to connect instruments, transmitters, and sampling points to the process. Instrumentation fittings are the connectors — compression tube fittings, socket weld fittings, and threaded fittings — that join tubing to instruments, manifolds, and process lines while maintaining a leak-tight seal.

Q2: What are the main types of instrumentation fittings?
A: The main types include: Compression tube fittings — single ferrule and double ferrule designs; ASME B16.11 forged fittings — socket weld and threaded (NPT/BSP); and tube adapters — male/female connectors for tube-to-thread transitions.

Q3: What is the difference between single ferrule and double ferrule fittings?
A: Double ferrule fittings use a front ferrule to seal and a back ferrule to grip the tube independently, offering up to 15,000 psi (1/4" 316SS) , multiple remakes, and excellent vibration resistance. Single ferrule fittings use one ferrule for both sealing and gripping, offering up to 10,000 psi, simpler assembly, and lower cost — suitable for general instrumentation where repeated remakes are not critical.

Q4: What standards do your instrumentation tubing and fittings comply with?
A: Tubing: ASTM A269 (general service) and ASTM A213 (high-temperature / heat exchanger). Compression fittings: manufacturer proprietary designs equivalent to Swagelok / Parker standards. Forged fittings: ASME B16.11. Threads: ASME B1.20.1 (NPT). Piping design: ASME B31.3.

Q5: What is ASME B16.11 and what does it cover?
A: ASME B16.11 is the standard for forged steel fittings used in socket weld and threaded piping systems. It covers dimensions, tolerances, pressure ratings, and marking for fittings from NPS 1/8 to NPS 4, with pressure classes 2000, 3000, 6000, and 9000.

Q6: What is the pressure rating of ASME B16.11 fittings?
A: Socket weld: 3000#, 6000#, 9000#. Threaded: 2000#, 3000#, 6000#. Each class corresponds to a matching pipe schedule: 3000# → SCH 80; 6000# → SCH 160; 9000# → XXS.

Q7: What is the pressure rating of your instrumentation tubing?
A: Pressure rating depends on tube OD, wall thickness, and material. Example: 1/4" OD × 0.035" wall 316L seamless tubing is rated approximately 5,100 psig (351 bar) at -20 to 100°F. Thicker walls and larger OD sizes carry higher ratings. Full pressure tables are available upon request.

Q8: What materials are used for instrumentation tubing and fittings?
A: Standard: AISI 316/316L stainless steel (heat code traceable). Optional: 304/304L, Alloy 625 (subsea, sour service), Monel 400 (seawater, HF acid), Alloy 825 (corrosive chemical), and Duplex 2205 (high strength + chloride resistance).

Q9: What is the temperature range for 316L instrumentation tubing?
A: 316/316L stainless steel instrumentation tubing can operate from approximately -198°C to +537°C (-325°F to +1000°F) depending on the specific standard (A269 or A213) and wall thickness.

Q10: What tube sizes are available?
A: Fittings: 1/16" to 2" OD. Tubing (standard): 1/8", 1/4", 3/8", 1/2", 3/4", 1" OD; metric 6 mm, 8 mm, 10 mm, 12 mm, 16 mm, 25 mm. Custom sizes available upon request.

Q11: What is the difference between NPT and BSP threads?
A: NPT (National Pipe Taper) is the American tapered thread standard per ASME B1.20.1. BSP (British Standard Pipe) is the British/European thread standard, available in BSPP (parallel) and BSPT (tapered) forms. NPT and BSP threads are not interchangeable — mixing them can cause leaks or damage.

Q12: What is the 1/16" expansion gap in socket weld fittings?
A: When installing socket weld fittings, the pipe is inserted fully into the socket and then pulled back approximately 1/16" (1.6 mm) before welding. This gap allows for thermal expansion during operation. Without it, thermal growth can crack the fillet weld. ASME B31.3 and most fabrication procedures mandate this gap.

Q13: When should I use socket weld vs threaded fittings?
A: Use socket weld for flammable, toxic, high-pressure fluids, significant thermal cycling, vibration, and where a welded leak-proof connection is required (Class 6000/9000). Use threaded where frequent disassembly is needed (instrument connections, sampling points), welding is not permitted, or for low-pressure utility services (air, water, nitrogen).

Q14: What is the difference between ASTM A269 and ASTM A213 tubing?
A: ASTM A269 covers seamless and welded austenitic stainless steel tubing for general service. ASTM A213 covers seamless ferritic and austenitic steel boiler, superheater, and heat exchanger tubes. Both are used for instrumentation, but A213 is specified where higher temperature or heat exchanger service is involved.

Q15: Can instrumentation fittings be used in sour service (H₂S)?
A: Yes. We offer NACE MR0175 construction with controlled material hardness for sulfide stress cracking resistance. Alloy 625 and Monel 400 are commonly selected for sour and corrosive service.

Q16: What fitting configurations are available?
A: Unions (straight, reducing), elbows (90° / 45°), tees (union, reducing, run, branch), crosses, bulkhead unions / elbows, male/female connectors, caps, and plugs.

Q17: How do I select the right fitting for my application?
A: Key factors: (1) Pressure rating — match system design pressure; (2) Connection method — compression (no weld) vs socket weld vs threaded; (3) Material — 316SS standard, Alloy 625 / Monel for corrosive; (4) Tube size — OD and wall thickness; (5) Temperature; (6) Remake requirements — double ferrule for repeated remakes; (7) Vibration — double ferrule or socket weld preferred.

Q18: What certificates are provided with your tubing and fittings?
A: Standard: EN 10204 3.1 mill certificates with heat code traceability. Additional services: PMI (Positive Material Identification) , hardness testing, dimensional inspection, and hydrostatic / gas testing.

Q19: Do you support EPC projects with technical documentation?
A: Yes. We provide datasheets, dimension drawings, material certificates, pressure rating tables, and full traceability documentation for EPC project compliance. Our engineering team can review your instrumentation specifications and recommend the optimal tubing and fitting solution.

Q20: Can you provide custom instrumentation tubing and fitting configurations?
A: Yes. We offer custom materials (Alloy 625, Monel, Alloy 825, Duplex), sizes, wall thicknesses, fitting configurations, and special thread types to meet project-specific requirements. Our engineering team works closely with EPC contractors to develop solutions that match specific piping classes, instrument connections, and service conditions.

📩 Contact Us for EPC Project Pricing & Technical Support

Send your instrumentation specification, tubing schedule, or fitting requirements. Our engineering team will reply with a customized BOM, datasheet & material certificates within 24 hours.

✉ Get Free Quote Now

WhatsApp / Zalo: +86 17856068126  |  Email: [email protected]