flange size chart & slip on flange gasket for piping | Wholesale

Slip On Flange Gasket & Flange Size Chart: Complete Piping Specs for Wholesale Buyers

Does your procurement team struggle with flange–gasket mismatches that cause leaks and costly downtime? Our wholesale slip on flange gasket solutions, paired with a precision-engineered flange size chart (ASME B16.5), give your team a single reliable source for dimensionally accurate, fully certified piping components. Stop juggling multiple vendors—get factory-direct pricing with 7-day global delivery.

✔ Trusted by 20+ countries  ✔ ISO 9001 Certified  ✔ ASME B16.5 Compliant

🏭 50,000 m² Production Base in Hebei, China

Flange–Gasket Dimensional Mismatch

Purchasing a slip on flange gasket based on nominal pipe size alone is the #1 error. ASME B16.20 gasket ODs differ by pressure class. A wrong ID causes turbulence; a wrong OD causes blowout. One leak = 4 hours of unplanned shutdown.

Multi-Vendor Quality Inconsistency

Source flanges from one supplier, gaskets from another, bolts from a third: nobody owns the tolerance stack-up. Batch-to-batch variance in flange facing finish alone can cause 30% higher gasket seating stress requirements.

Freight Costs Eating 25–30% of P.O. Value

Consolidated LCL shipments from Asia cost up to 30% more per kg when suppliers can’t commit to manifest dates. Our average outbound loading time is 5 days—not 5 weeks.

Standards Compliance Gaps

ASME B31.3 requires that pipe-branch connections (tees) and flange joints sustain calculated stress indices. If your supplier can’t provide mill test reports and certificate traceability, your plant is exposed to audit failures.

Wrong Gasket Material Selection

A 2025 paper in Cureus Journal of Engineering demonstrated that rigid flange coupling material choices—evaluated for mechanical properties, corrosion resistance and thermal stability—can reduce in-service failure risk by 42% when optimized systematically. Yet 61% of buyers still select gaskets by price alone.

No Technical Support After the Sale

When you need a revised flange size chart for a Class 300 upgrade, or a gasket compound recommendation for a new chemical line, does your current supplier answer? Ours do—within 2 hours, by engineers who have built piping systems.

ASME B16.5 Certified Flange Size Chart

Every flange we produce is dimensionally verified against ANSI/ASME B16.5. We provide a flange size chart covering Classes 150, 300, 600, 900 and 1500, in both inch and metric. Our chart includes bolt circle diameters, hub lengths, and facing dimensions—so your purchasing team never guesses again.

Engineered Slip On Flange Gaskets

Our slip on flange gasket range includes compressed non-asbestos fiber (CNAF), graphite, PTFE, and metal-reinforced styles. Each gasket is die-cut to ISO 7483 or ASME B16.21 dimensions, ensuring a perfect match to standard slip-on flanges. We also offer custom rubber compounds for chemical compatibility.

OEM / ODM Design & Custom Fabrication

Need a special facing finish? A custom bolt pattern for an obsolete legacy system? Our engineers use 3D modeling (SolidWorks) and CNC machining to produce custom flanges and gaskets in as little as 10 days, with full material traceability.

High-Speed Delivery & Consolidated Logistics

Our average production lead time for standard flanges is 7–15 days. We consolidate multi-item orders into single container shipments, cutting your per-kg freight costs by up to 28%. Standard export packaging meets IPPC/ISPM 15 for all markets.

Material Traceability

MTR (EN 10204 3.1) available for all carbon steel, stainless 304/316, and alloy flanges.

Quality Control

100% hydrostatic and NDT testing options (UT, MT, PT) per your P.O. requirements.

Global Standards

ASME B16.5, DIN EN 1092-1, JIS B2220, GOST 12820 — we produce to all major standards.

Oil & Gas Offshore Pipelines

A 2024 study in Brodogradnja found that optimized offshore flange connectors achieved maximum contact pressure with 18% lower equivalent stress—exactly the failure-resistance profile we replicate in our own flange design consultations. We supply Class 600–1500 slip-on flanges and spiral-wound gaskets for subsea chemical injection and topside process piping.

Chemical Processing Plants

For aggressive media, we recommend PTFE or graphite-filled slip on flange gasket configurations. Our 100% PTFE gaskets handle pH 0–14; our graphite gaskets sustain temperatures to 850°F. Every gasket is batch-coded for factory audit traceability. “We reduced seal failures by 64% after switching to Weihuan PTFE gaskets,” says a plant engineer in Texas.

Water & Wastewater Treatment

We supply EPDM-faced slip-on gaskets and fusion-bonded epoxy-coated flanges for desalination and municipal water projects. Our EPDM gaskets comply with WRAS/KTW for potable water. One municipal project in Canada ordered 2,400 units; we shipped in 18 days, saving them 5 weeks versus the previous supplier’s lead time.

Power Generation & Boiler Systems

In high-vibration environments, bolt preload relaxation is a silent killer. A 2012 study in the Journal of Sound and Vibration modeled bolted flange joints and found that dynamic loads cause flange gasket creep at the bolt interfaces, requiring correctly torqued, high-grade studs and gaskets. We bundle flanges + gaskets + galvanized A193 B7 studs into one ready-to-install kit.

CNC Facing Line

Ready-to-Ship Inventory

Gasket QC Inspection

Q: How do I read the flange size chart to match a slip on flange gasket?

First, identify the flange pressure class (150, 300, 600, etc.) and nominal pipe size. The flange OD and ID determine the gasket OD. Per ASME B16.21, the gasket OD should be slightly smaller than the bolt circle diameter, and the gasket ID should equal the flange bore. Use our flange size chart to cross-reference these values before ordering.

Q: What is the lead time for wholesale flange + gasket orders?

Standard carbon steel slip-on flanges: 7–12 days. Stainless steel: 12–15 days. Gaskets (CNAF, PTFE, EPDM): 3–5 days. For a combined 20-ft container order, typical total production time is 12–18 days before FOB or CIF shipment.

Q: Can you provide custom gasket dimensions for a non-standard slip on flange?

Yes. Our die-cut and waterjet cutting lines handle custom ODs, IDs, and thicknesses from 0.5 mm to 5 mm. Send us a drawing or a worn sample; our engineering team will reverse-engineer it and provide a dimension report within 48 hours.

Q: Do you offer OEM / white-label packaging for distributors?

Absolutely. We provide OEM/ODM services: custom barcode labels, distributor-branded cartons, mixed-container packing lists, and digital photos of every pallet before loading. Our platform-based model supports both branded and unbranded supply.

Q: What payment terms do you accept for wholesale orders?

We accept T/T (30% deposit, 70% against B/L copy), L/C at sight, and for established customers, D/P or net 30 terms up to $50,000 order value. All our invoices are fully compliant for Western tax and accounting filing.

Q: How is shipping cost optimized for small-volume trial orders?

For orders under 5 m³, we use a global express agent network (DHL/FedEx) with pre-negotiated freight rates—you save up to 22% versus booking a courier independently. For full containers, we consolidate with other buyers at our port to achieve FCL pricing with LCL volumes.

James R., Purchasing Lead, Texas

"We ordered Class 150 slip-on flanges and matching CNAF gaskets for a refinery revamp. Their flange size chart matched our site measurements perfectly — zero rejected on arrival. Saved us 31% compared to our previous distributor."

Sven M., Technical Director, Rotterdam

"The slip on flange gasket quality is outstanding — precise die-cutting, no loose fibers, consistent 1.6mm thickness across 3,000 pieces. Documentation was complete with MTR and EN 10204 3.1 certificates."

Ana S., Ops Manager, Alberta

"Our previous supplier quoted 8 weeks for 6-inch ANSI #150 flanges. Weihuan delivered in 12 days, including gaskets and bolts. We've Since placed 3 repeat orders."

Zhang Wei — Senior Piping Systems Engineer, Cangzhou Weihuan

With 15 years of experience in industrial piping system design and fabrication, Zhang Wei leads Weihuan's technical consulting team. He holds a BSc in Mechanical Engineering from Hebei University of Technology and has participated in 40+ cross-border pipeline projects, including offshore, petrochemical, and water infrastructure. Zhang is the author of Weihuan's Wholesale Piping Buyer's Handbook and regularly lectures on ASME B31.3 compliance for Chinese pipe fitting exporters.