Direct from Cangzhou Weihuan Pipeline Equipment Co., Ltd. — solve procurement cost volatility, thread-quality inconsistency, and long shipping lead times with factory-direct 1 1 2 threaded flange and 2 1 2 threaded flange solutions engineered for North American and European piping systems.
🏟 ISO 9001 • CE • 20+ Export Countries
Direct from Cangzhou Weihuan Pipeline Equipment Co., Ltd. — solve procurement cost volatility, thread-quality inconsistency, and long shipping lead times with factory-direct 1 1 2 threaded flange and 2 1 2 threaded flange solutions engineered for North American and European piping systems.
Purchasing managers and technical directors in the oil & gas, chemical, and water-treatment industries face the same recurring bottlenecks when sourcing 1 1/2 threaded flanges and 2 1/2 threaded flanges.
Buying through regional distributors instead of a threaded flange factory means paying significant premiums. A 2 1/2 inch threaded flange that costs $18–$24 FOB China often reaches buyers at $32–$45 through trading intermediaries.
Poorly machined NPT threads on low-cost flanges lead to galling, misalignment, and leak paths. One petrochemical refiner in Texas reported 12 flange-related repair incidents in a year caused by substandard thread depth tolerance.
Non-factory suppliers cannot control production schedules. When you need a mixed batch of 1 1/2 and 2 1/2 threaded flanges, delays of 4–8 weeks cause expensive field labor idle time and missed commissioning deadlines.
Flanges without traceable mill certificates fail EPC audits. ASME B31.1 and B31.3 piping systems require full material traceability — buyers sourcing from brokers often receive flanges without PMI tests or EN 10204 3.1 documentation.
Inexperienced consolidators cause damages in transit — bent hubs and stripped threads on threaded flanges. A well-planned factory logistics team can cut freight costs by 12–18% through LCL consolidation and proper export crating.
Need replacement flanges or technical support after the container arrives? Brokers often become unreachable. Factory-direct suppliers provide responsive engineering consultation, replacement parts on warranty, and consistent availability.
Bottom-line impact: These issues collectively cost a mid-sized plant operator $45,000–$70,000 per year in rework, downtime, and premium sourcing. There is a better way — go straight to the factory.
We are a platform-based supply chain enterprise in Hebei Province, China, directly managing a network of certified forging plants, CNC threading workshops, and export packing lines. When you order a 1 1 2 threaded flange or a 2 1 2 threaded flange from us, you get six distinct advantages:
Hot-die forging presses (1600T–4000T) produce flange bodies with uniform grain flow. CNC lathes with 3-jaw chucks hold thread tolerances to ASME B1.20.1 (NPT) within ±0.002 inch on pitch diameter.
A dedicated threading shop with 7-axis pipe-threading machines produces clean taper threads on all threaded flanges. Ring gauge and plug gauge inspection on 100% of the batch ensures no leak paths.
Mill certificates per EN 10204 3.1 provided with every heat. We use only ASTM A105, A182 F304/F316, or A350 LF2 forgings sourced from certified Chinese steel mills (TSG certified).
Standard production: 7–12 days for 500–2,000 pcs mixed sizes. We book weekly LCL/FCL sailings to Houston, Rotterdam, Singapore, and Dubai — transit times between 18–35 days door-to-door.
Need custom bore sizes, special facing, or non-standard thread sealants? Our design team supports OEM projects, including custom hub dimensions and surface treatments per your P&ID or isometric drawings.
Our export team crates flanges with marine-grade VCI paper, steel pallet frames, and bolt-hole alignment — reducing transit damage claims by 97% across last 12 months of shipments to North America and Europe.
All dimensions per ASME B16.5 — latest revision. Threads per ASME B1.20.1 NPT. Face finish per ASME B16.5 (125–250 μin Ra standard serrated).
| Parameter | 1 1/2" NPT Threaded Flange | 2 1/2" NPT Threaded Flange |
|---|---|---|
| Nominal Size | 1 1/2 inch (DN40) | 2 1/2 inch (DN65) |
| Pressure Class (150) | 285 psi WOG / 150 lb | 285 psi WOG / 150 lb |
| Pressure Class (300) | 740 psi WOG / 300 lb | 740 psi WOG / 300 lb |
| Flange Outside Diameter (Class 150) | 4.25 in (108 mm) | 5.50 in (140 mm) |
| Flange Thickness (Class 150) Min. | 0.56 in (14.2 mm) | 0.69 in (17.5 mm) |
| Bolt Circle Diameter (Class 150) | 3.12 in (79.4 mm) | 4.12 in (104.8 mm) |
| Bolt Holes (Qty / Diameter) | 4 x 0.62 in (16 mm) | 4 x 0.75 in (19 mm) |
| Raised Face Diameter | 2.88 in (73.2 mm) | 3.75 in (95.2 mm) |
| Thread Engagement Length | 0.56 in (14.2 mm) | 0.69 in (17.5 mm) |
| Available Face Types | RF, FF, RTJ (Class 300+) | RF, FF, RTJ (Class 300+) |
| Thread Standard | NPT per ASME B1.20.1 | NPT per ASME B1.20.1 |
| Marking | ASTM A105 / 150 / RF / NPT / heat code | ASTM A105 / 150 / RF / NPT / heat code |
💡 * Class 300 and Class 600 threaded flanges are also available with RF/RTJ facings. For pressure classes above 600, we recommend welding-neck or socket-weld flanges per ASME B31.3 engineering practice.
Material selection is the most critical determinant of flange service life. A 2025 paper in the Cureus Journal of Engineering on material selection in rigid flange coupling systems established a decision matrix for optimizing mechanical properties, corrosion resistance, thermal stability, and cost-effectiveness. We apply precisely that logic to every threaded flange we produce.
Working pressure: 285 psi (Class 150) at 100°F
Temp range: -20°F to 1000°F (ambient to high-temp water/steam)
Yield strength: 36,000 psi min.
Ideal for: oil & gas, general industrial, fire protection systems
F316 molybdenum adds chloride resistance for marine / chemical use
Temp range: -425°F to 1200°F (cryogenic to high-temp)
Yield strength: 30,000 psi min. (F304)
Ideal for: chemical processing, food & beverage, pharmaceutical, offshore
Threaded flanges are installed in low-pressure, small-bore branches where welded connections are impractical or where field disassembly is required. Our clients use these flanges across the following sectors:
Wellhead test lines, meter runs, and low-pressure gathering lines. A 1 1/2 threaded flange with Class 300 rating is commonly used above the wellhead choke for ROV-retrievable flowline connections.
Injection skids and sampling systems where stainless steel (F316) is needed for corrosive chemicals. Threaded connections allow rapid maintenance without hot-work permits.
Backwash lines, aeration headers, and chemical feed stations. 2 1/2 threaded flanges in Class 150 are standard for in-plant piping up to 150 psi water pressure.
Fast, code-compliant installation for fire water mains and sprinkler branch lines. Threaded flanges meet NFPA 24 requirements for above-ground pipe connections.
A Vancouver-based EPC contractor needed 840 pcs of 1 1/2 threaded flange (ASTM A105, Class 150 RF) and 420 pcs of 2 1/2 threaded flange (ASTM A105, Class 150 RF) for a municipal water treatment upgrade. They had abandoned their previous distributor after a 4-week shipment delay.
Order placed: Tuesday, production started Thursday
All flanges packaged and loaded in 9 days
Shipment arrived at Vancouver port in 24 days (air + rail to site)
Final quality audit: 0 defects on thread gauge inspection
Saved buyer 31% off previous listed price and 3 weeks of schedule time
ISO 9001:2015
Quality Management System
CE Mark
Pressure Equipment Directive 2014/68/EU
UL / cUL Listed
For fire protection sprinkler applications
In addition to the above, every countersunk & threaded flange shipment includes:
EN 10204 3.1 mill test certificate for all pressure-containing materials
PMI (Positive Material Identification) test report for stainless steel alloys
ASME B16.5 dimensional conformity report signed by QA inspector
Thread plug gauge & ring gauge certificates traceable to NIST standards
Fumigation-free wooden crating per ISPM 15 for North America and EU customs
Our standard MOQ is 50 pieces per size for Class 150 and Class 300 threaded flanges in ASTM A105 or stainless steel. For mixed-size orders of 100+ pieces, we can combine different sizes (e.g., 60 pcs of 1 1/2" and 40 pcs of 2 1/2") at no extra cost. If you need fewer than 50 pieces, please contact us — we do keep some buffer stock for urgent projects.
Absolutely. We support OEM/ODM customization including: zinc-plated (clear or yellow), hot-dip galvanized, PTFE-coated, or phosphate-coated threads. For special face finishes (e.g., smooth RF at 32 μin Ra for spiral-wound gaskets), we can machine to your spec. Just share your drawings or reference standard — our engineering team will confirm applicability within 24 hours.
We ship via sea freight (FOB/CIF/CFR), air freight, or express (DHL/FedEx) depending on order weight and urgency. For typical orders of 200–500 kg of threaded flanges:
LCL sea freight to Houston: about $15–$25 per cubic meter (depending on season)
Air freight to Chicago: $4–$7 per kg
DHL express: $6–$10 per kg for urgent spare parts
Yes, we offer both NPT (ASME B1.20.1) and BSPP / BSPT (ISO 228 / ISO 7-1) thread forms. Most clients in the Netherlands, Germany, and the UK order BSP threads with a parallel (G) or taper (R) profile. Please state your thread standard when requesting a quote.
We offer a 24-month warranty against manufacturing defects including thread machining errors, material porosity, and dimensional nonconformity. If a defective flange is found, send us the batch number (marked on each flange) and photos — we will dispatch replacements via express at no charge, and cover the warranty logistics. We have a 97% resolution rate within 7 business days.
A custom 1 1/2 or 2 1/2 threaded flange with changed hub length, OD, or facing requires new forging dies only if the outside diameter changes significantly. Minor dimensional tweaks can be done with existing dies — lead time is typically 14–18 days for production plus transit. If new dies are needed, add 10–12 days for die manufacturing. We'll confirm the exact feasibility and time with the drawing review.
"I've been buying threaded flanges for 17 years. Weihuan's 2 1/2 threaded flanges are the first batch I received in China where every single flange passed our AQL 1.0 inspection on the first pass. Their NPT thread depth is consistently within tolerance."
"We ordered a mixed lot of 1 1/2 threaded flange with RF facing and 2 1/2 threaded flanges for a hospital extension project. The factory-issued EN 10204 3.1 certificates satisfied our third-party inspector instantly. Delivery from China to New York took 27 days."
"In Kazakhstan, we face extreme winter temperatures down to -40°C. The A350 LF2 low-temp threaded flanges from this factory performed flawlessly. Our mechanical contractor praised the clean threads that torqued properly even with severe frost."
Zhang Wei
Senior Piping Component Engineer & Export Compliance Specialist — 18 years in forged flanges and piping systems for the oil, gas, and process industries. Member of ASME B31 piping code committees (observer) and a certified API 510 pressure vessel inspector (in training).
Zhang has personally overseen the production and QA of over 2,300 tons of threaded flanges and pipe fittings exported to the US, EU, and Middle East. He leads technical training for dealership teams across 8 countries and frequently contributes to piping engineering communities on flange joint reliability.
This article reflects Zhang's independent professional experience and is intended for informational purposes only. Always consult a licensed engineer before making final design decisions.
Screenshots from recent customer conversations — showing responsive communication, technical support, and fast quotation.
Send your RFQ today and get a detailed quotation within 24 hours, including real-time mill availability, freight estimates, and full compliance documentation. Limited sample stock available for qualified projects.
Your business information and project details are treated as confidential per our privacy policy.
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🏯 Trusted by Engineering-Driven Companies Across 20+ Countries
💬 "We sourced 2 1/2 threaded flanges from four suppliers before trying Weihuan. The threading quality was visibly better — the gauge fit was perfect on all 300 pieces."
💬 "Our chemical plant needed F316 stainless 1 1/2 threaded flanges with a 48-hour quote and 10-day production. The team delivered all paperwork — even the PMI test reports — before the cargo reached Rotterdam."
💬 "The factory-direct model is real. We cut our unit cost by over 28% versus our old import agent, and the quality is more consistent. The 2 1/2 threaded flanges came zinc-coated exactly per our spec."