Instrumentation Pipe & Weld Fittings Manufacturer(ASME B31.3)
Zero-leak connections for 10,000 psig service. 100% Heat Code Traceable 316SS forgings. Functionally interchangeable with Hy-Lok & Swagelok.
Engineered for critical process control. Our NPT threads are rolled for 30% higher surface hardness, preventing galling. Our socket weld ports feature a machined taper to ensure the ASME-mandated 1/16″ expansion gap. Available in 1/8″ to 1″ sizes with EN 10204 3.1 certification.
Engineering Excellence
Precision Engineering for Zero-Leak Performance
Sunhy delivers instrumentation fittings that exceed the rigorous demands of ASME B31.3 Process Piping Codes. Unlike standard machining, we utilize rolled thread technology to increase surface hardness by 30%, preventing galling during assembly. For welded systems, our unique tapered socket design ensures precise pipe alignment and automatically sets the required welding gap, eliminating stress corrosion risks in high-vibration environments.
Advanced CNC Fleet
- 120+ units of Mazak/Doosan class lathes
- Rolled Male Threads (vs. Cut Threads)
➜ Ra 0.4µm internal surface finish
➜ 30% higher fatigue strength
Single-Setup Machining
- 5-Axis machining for complex Tee/Cross bodies
- Guaranteed Concentricity < 0.05mm
➜ Eliminates misalignment leaks
➜ 100% PMI (Spectral Analysis) verification
High-Pressure Capabilities
- Rated up to 10,000 psig (689 bar)
- 4:1 Safety Factor (Burst Test Verified)
- Heat Code Traceability (EN 10204 3.1)
➜ Interchangeable with Hy-Lok & Swagelok
Our Products
Product Categories & Series
Threaded Adapters & Connectors
Male/Female NPT adapters and reducing couplings for seamless instrument interface.
Nipples & Bushings
Hex nipples and reducing bushings machined from ASTM A479 bar stock for high precision.
Plugs, Caps & Unions
Leak-tight sealing plugs and pipe unions for system maintenance and pressure testing.
Weld Elbows & Reducers
ASME B16.11 compliant socket weld elbows for high-pressure steam and chemical lines.
Core Technologies
Leak-Free Integrity via Rolled Thread Technology
Standard cut threads tear the metal grain structure, creating weak points susceptible to vibration fatigue. Sunhy utilizes advanced thread rolling technology for all male NPT threads. This cold-forming process compresses the grain flow, resulting in a 30% increase in surface hardness and superior resistance to galling during assembly. Combined with our tapered socket weld ports that automatically set the ASME-mandated 1.5mm expansion gap, our fittings eliminate the two most common causes of system failure: thread deformation and weld stress cracking.
Complete Instrumentation Portfolio (1/8" to 1")
Sunhy offers a fully integrated piping solution engineered to ASME B31.3 Process Piping standards. From ASTM A182 F316 forgings for high-stress tees to ASTM A479 bar stock for straight connectors, every component is designated with a Heat Code for 100% traceability. Our inventory mirrors the Hy-Lok H-Series and Swagelok dimension standards, allowing for seamless mix-and-match compatibility in MRO (Maintenance, Repair, and Operations) scenarios without re-engineering your panels.
Threaded (NPT/ISO 7-1):
- H-SLA Forged Elbows (Grain-oriented structure)
- H-SML Male Elbows (Rolled Threads)
- H-STA/H-SXA Tees & Crosses
- 10k High-Pressure Series (Heavy Wall)
Weld Fittings (ASME B16.11):
- H-SWFC Socket Weld Unions
- H-SWRM Pipe-to-Tube Weld Adapters
- Tapered socket design for auto-alignment
- Class 3000 / 6000 Pressure Ratings
Specialty & Materials:
- Sour Gas Service (NACE MR0175 compliant)
- Custom Alloys: Monel 400, Hastelloy C-276
- Oxygen Service Cleaning (ASTM G93)
- Temperature Rating: -325°F to 1000°F
Manufacturing: The Precision of CNC
Quality at Sunhy is defined by our investment in 5-Axis CNC Machining Centers (Mazak/Doosan class). Unlike conventional machining which requires multiple setups, our single-setup process machines all ports of a Tee or Cross simultaneously. This guarantees axial concentricity within 0.05mm, ensuring that flow paths perfectly align and turbulence is minimized. For raw materials, we do not rely on supplier certs alone; we conduct in-house verification to ensure every batch of 316SS meets the molybdenum content requirements for marine-grade corrosion resistance.
- 120+ CNC Spindles for mass consistency
- Single-Setup machining for complex geometries
- In-house Tooling Workshop for custom threads
- Electropolishing capabilities for ultra-high purity
Verification
Inspection Plan & PMI Requirements
Before any fitting leaves our Wenzhou facility, it undergoes a rigorous validation process. We utilize Handheld XRF Spectrometers to perform PMI (Positive Material Identification) on 100% of outgoing stainless steel orders, preventing dangerous alloy mix-ups. Dimensional accuracy is verified using CMM (Coordinate Measuring Machines) to ensure thread pitch and taper angles strictly adhere to ANSI B1.20.1. Finally, fittings are ultrasonically cleaned to remove machining oil and metal fines, delivered ready for oxygen or critical process service.
Global Compliance & Certification
Sunhy Pipe Fittings Co., Ltd. operates under a quality system audited by DNV and Bureau Veritas. Our instrumentation fittings comply with the European Pressure Equipment Directive (PED 2014/68/EU), ensuring safety for pressurized systems >0.5 bar. We provide EN 10204 3.1 Material Test Reports (MTRs) with every shipment, detailing chemical composition, mechanical properties, and heat treatment history. This comprehensive documentation package supports your compliance with ASME B31.1 (Power Piping) and B31.3 (Process Piping) audits.
Experience the Sunhy Difference
Global Logistics & Certified Traceability
Sunhy transforms complex procurement into a streamlined process. We support critical infrastructure in 30+ countries, ensuring every ASME B31.3 compliant fitting reaches your site with full EN 10204 3.1 Material Test Reports (MTRs). Whether fulfilling urgent MRO (Maintenance) requirements or scheduled OEM bulk orders, our logistical expertise guarantees that your 316SS NPT and Weld fittings arrive on time, pass receiving inspections, and are ready for immediate installation.
Dedicated Customer Support Teams
Serving Impressive List Of Long Term Clients!
Our growth is a testament to how much we value our customers. Exceptional customer service has been the key to our success, ensuring satisfaction and fostering loyalty. Thank you for helping us grow together.
Seeing is believing
About Sunhy
See Quality in the Making, Build Trust in Person
Visit Sunhy Factory: See Quality, Build Trust
🏭 Full-Process Tour
See precision machining, assembly, and testing—witness how each stainless steel fitting is born.
🤝 Technical Exchange
Our engineers provide on-site support for selection, customization, and solutions.
Submit your visit request—we’ll contact you within 24h to plan your custom tour.
