blind flange 3 & 14 blind flange for piping systems | Wholesale

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Hidden price inflation up to 35%

Tier-2 distributors mark up blind flanges 25–35% above factory-gate prices. For a 14 blind flange in stainless steel, that's $180–$300 extra per piece — before freight.

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Sub-standard raw material

Some budget suppliers substitute A105 with low-grade carbon steel, skipping heat-treatment. Result: premature gasket-face corrosion and in-service failure within 18 months.

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Freight & logistics surprises

High shipping costs for heavy forgings eat into savings. Without consolidated LCL planning, buyers pay up to $600 extra per cubic meter for oversized blind flange crates.

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Missing certification & traceability

API/ISO certificates that arrive "after shipment" often fail audit. Without EN 10204 3.1 mill certs, your QA team rejects the batch — wasting 6–8 weeks.

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Delivery delays of 20+ weeks

Non-integrated suppliers outsource forging, heat treatment, and machining to 3 different shops. Coordination chaos leads to typical slippage of 4–8 weeks.

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Zero after-sales engineering support

When a face finish doesn't match your gasket spec, most suppliers go silent. You need a partner who answers within 4 hours — not 4 days.

✅ The Factory-Direct Solution: Cangzhou Weihuan Pipeline Equipment

We are not a trading company. We are a platform-based supply chain enterprise in Cangzhou, Hebei — the heart of China's pipe fitting manufacturing cluster. Our sales team works directly with ISO 9001-certified forging and machining partners, giving you complete control over quality, cost, and delivery.

• 100% material traceability — Mill test certificates per EN 10204 3.1 / 3.2

• OEM/ODM design support — Custom thickness, facing, and drilling per your drawing

• High-speed delivery — 30–40 days for standard ASTM blind flanges; 15 days for hot-rush production

• Export experience — 20+ countries incl. USA, Canada, Russia, Germany, UAE, Kazakhstan

• 3rd-party inspection welcome — SGS, BV, TÜV accepted at our workshop

✓ Small MOQ: 50 pcs for standard blind flanges

Cangzhou Weihuan forging & machining workshop, Hebei Province

🔷 Blind Flange 3 (DN80)

Class 150 / 300 / 600

⚡ Available face finishes: RF (125–250 µin Ra), FF, RTJ. Bolt-hole alignment per ASME B16.5.

🔸 14 Blind Flange (DN350)

Class 150 / 300 / 600

⚡ Heavier thickness available per ASME B16.47 Series A/B for high-pressure or large-bore isolation duty.

ASTM A105 (Carbon Steel)

Service: General hydrocarbon, water, and steam up to 425°C. Standard bulk material for blind flange 3 and 14 blind flange in Class 150–600.

ASTM A182 F304 / F316 (SS)

Service: Corrosive, cryogenic, and high-purity media. F316 offers enhanced pitting resistance in chloride-laden coastal and chemical environments.

ASTM A350 LF2 (Low-Temp)

Service: Low-temperature carbon steel for cold-climate piping and LNG. Charpy tested at -46°C per ASME B16.5 requirements.

ASTM A182 F11 / F22 (Cr-Mo)

Service: High-temperature and high-hydrogen partial-pressure service. Elevated strength for heavy-wall 14 blind flange in refinery hydrocracking units.

🛡️ Face Types, Surface Finish & Sealing Performance

Choosing the correct flange face is as critical as the material grade. As documented in the Cureus Journal of Engineering (2025) paper on rigid flange coupling material selection, optimizing the face-contact interface directly reduces both over-specification waste and in-service leakage risk. We manufacture:

• Raised Face (RF) — 1.6 mm / 6.35 mm height for Class 150–300 and Class 400–2500 respectively; finish 125–250 µin Ra

• Flat Face (FF) — for cast iron or non-metallic mating components

• Ring-Type Joint (RTJ) — for high-pressure gas and hydrocarbon service; octagonal or oval ring grooves per API 6A / ASME B16.20

• Lapped / T&G — custom options for special gasket systems

Our machining center maintains a surface finish of 125–250 µin Ra, ensuring a leak-tight seal with spiral-wound, sheet, or Kammprofile gaskets.

📝 Engineering & Design References

References available in our technical library — request the full paper citations with your RFQ.

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Oil & Gas Production

Blind flanges isolate pumps, valves, and pressure vessels during maintenance or commissioning. A 14 blind flange at a wellhead manifold permits safe hydrotesting. ASTM A350 LF2 versions for arctic pipeline service.

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Chemical Processing

Stainless steel blind flange 3  units cap reactor nozzles and sample lines in aggressive media. F316 material with 2205 duplex available for chlor-alkali and acid-handling environments.

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Water & Wastewater

Large-diameter 14 blind flange in Class 150 ductile/carbon steel isolates pump stations and treatment trains. Epoxy-coated options meet AWWA C210 for potable water contact.

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Power Generation

High-temperature Cr-Mo (F22) blind flanges in boiler feedwater and steam systems. Class 600–2500 ratings for supercritical cycle isolation.

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Shipbuilding & Offshore

Blind flanges for ballast lines, fire mains, and cargo systems. Type-approved materials with DNV/GL and ABS documentation. 14 blind flange commonly used on platform deck piping.

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HVAC & Industrial Cooling

Cost-effective A105 blind flanges with galvanized or enamel coating for chilled water and cooling tower isolation. Fast production for maintenance shutdowns.

GE

Bosch

Accenture

Shenhua

ISO 9001:2015

ANSI / ASME B16.5

UL Listed (on request)

TÜV GS / CE

📍 USA — Texas Petrochemical Facility

"Needed 120 pcs of 14 blind flange Class 150 RF for a turnaround. Weihuan delivered in 27 days with full MTR and SGS inspection. The facing was flawless — zero leaks on hydrotest."

— PM, Gulf Coast Refinery (NDA protected)

🇬🇧 Germany — Chemical Plant

"Our supplier let us down on 3-inch blind flanges in 1.4571. Weihuan's engineering team redrew the spec and shipped compliant parts with DIN EN 10204 3.1 certs in 5 weeks. Saved us 30% vs European market."

— Einkaufsleiter, Specialty Chemicals Co.

🇮🇳 UAE — Oil & Gas EPC

"We have used Weihuan as our blind flange vendor for two major projects. Their consistency on 14-inch carbon steel blind flanges with RTJ facing is remarkable. Excellent communication and documentation."

— Senior Procurement Eng., Middle East EPC

Q1: What is the difference between a blind flange 3 and a standard 3-inch welding neck flange?

A blind flange is a solid disc with no center bore, used to close off a pipe end, nozzle, or valve. A 3-inch welding neck flange is welded to the pipe and provides a connection point. The blind flange 3 has a flat or raised face and no hub — its function is isolation, not connection. It is typically 20–40% lighter than a comparable weld neck flange, making it a cost-effective choice for test packs, future tie-ins, and temporary line closures.

Q2: Which pressure ratings are available for a 14 blind flange?

We manufacture 14 blind flange in Class 150, 300, 600, 900, and 1500 per ASME B16.5, and up to 2500# on request. For larger diameters, ASME B16.47 Series A (MSS SP-44 style) covers sizes from 26" to 60". Common stock items are Class 150 and 300, which cover the majority of water, hydrocarbon, and low-pressure steam service applications.

Q3: Can you supply blind flange 3 in stainless steel with a polished face?

Yes. We supply blind flange 3 in ASTM A182 F304, F316L, F321, and duplex grades (F51/F53). The RF face can be machined to 125–250 µin Ra standard, or polished to 32 µin Ra for hygienic and ultra-pure pharmaceutical applications. Gasket-surface finish verification is performed with a profilometer on each batch.

Q4: What is your wholesale MOQ and do you offer sample orders?

For standard carbon steel blind flanges, our MOQ is 50 pieces for sizes up to 24". For stainless steel, the MOQ is 30 pieces. A single-piece sample is available at a nominal fee (refundable with your first bulk order). We encourage sample orders for material verification and dimensional approval before mass production.

Q5: How do you handle shipping costs for heavy 14 blind flange orders?

Blind flanges are heavy; a 14" Class 300 RF unit weighs about 75 kg. We optimize logistics by consolidating your order with other fitting products (elbows, tees, reducers) into full or shared 20' containers. Our logistics desk calculates the most economical Incoterm — FOB Tianjin/Xingang, CIF, or DDP — and we achieve 15–25% freight savings through volume contracts with COSCO, Maersk, and MSC.

Q6: Do you provide OEM / custom drilling for blind flange 3 and 14 blind flange?

Absolutely. Our OEM/ODM capability includes custom bolt-hole patterns, facing styles (RF, FF, RTJ, T&G), counterboring, and special thickness. We hold dimensional tolerances to ±0.5 mm on OD and bolt circle, and face-surface flatness within 0.05 mm total runout. Send your drawing or flange standard for rapid quotation.

Q7: What documentation do you provide with wholesale shipments?

Each shipment includes: Commercial Invoice & Packing List, Bill of Lading, EN 10204 3.1 Material Test Certificates (or 3.2 with third-party inspection), Heat Treatment Charts, Charpy Impact Test Reports (for LF2/LF3), Dimensional Inspection Reports, NDT reports (UT/MT/PT as required), and the Certificate of Origin. If you require full compliance documentation, we prepare a project-specific ITP (Inspection & Test Plan) aligned to your quality requirements.

John Miller

Purchasing Manager, Midwest Petrochem Solutions

"We order 14 blind flange Class 150 in batches of 200+ for our facility expansion. Weihuan's pricing gave us a 22% saving vs our previous distributor, and the RF finish quality has been 100% consistent across five shipments. Their QC team sends real photos before loading."

Robert Klein

Technical Director, Rheinische Industrieanlagen GmbH

"I'm very particular about EN 1092-1 compliance and mill certs. Weihuan's blind flange 3 stainless steel units arrived with full 3.1 certification and the surface finish measured exactly 180 µin Ra. I sent a cross-check sample to an independent lab — chemistry and hardness were spot on."

Ahmed Al-Rashidi

Procurement Lead, Gulf Energy Contracting

"The fastest lead time we've achieved from China — 4 weeks from PI to port for 14 blind flange Class 600 carbon steel. Their logistics team handled the packing exceptionally well; not a single scratch on the faces in three containers. Highly recommend."

Elena Petrova

Supply Chain Manager, EuroAsian Pipeline Services

"We had urgent shutdown maintenance and needed both blind flange 3 and 14 blind flange within 3 weeks. Weihuan's team fast-tracked our order, communicated via WhatsApp every day, and made the vessel. Their speed saved us thousands in extended shutdown costs."

David O'Connor

Operations Director, Irish Water Infrastructure Group

"We standardized on Weihuan for all our flange needs across municipal water projects. The A105 blind flanges consistently pass our incoming inspection with ISO 9001 documentation. The cost advantage is enormous — about 18% lower than our previous EU supplier."

Lucas Moreau

Mechanical Engineer, Atlantic Marine Refit

"We refit offshore supply vessels and need large-bore blind flanges with marine-grade certification. Weihuan provided 14 blind flange with DNV-accepted material certs and salt-spray-tested epoxy coating. The quality-to-price ratio is why we stay with them."