Custom Forged Stainless Steel Flange Manufacturer: HuaboPipe

Looking for a manufacturer that can make non-standard forged stainless steel flanges? Contact HuaboPipe. All HuaboPipe stainless steel flanges are formed by forging and pressing. Types include welding neck (WN), slip-on (SO), long welding neck (LWN), blind and lap joint flanges. Outside diameter, thickness, bolt holes, neck length, bore and facing can all follow your drawing. Standard DN15–DN1200, larger to drawing up to DN3000. Standard flanges are made to EN 1092-1, GB/T 9124 or HG/T 20592, and to ASME B16.5 dimensions. Stocked grades: 304/304L, 316/316L, 310S, 321, 2205 and 2507.

What we make: types, grades and standards

• Welding neck flange (WN): butt-welded to the pipe; suited to lines with high pressure, large temperature changes, vibration, or welds that need radiography.
• Slip-on flange (SO): slides over the pipe and is fillet-welded, so installation is quick. Large diameter SO flanges are made to drawing; small-bore standard dimensions are not simply scaled up.
• Long welding neck flange (LWN): common on vessel and heat exchanger nozzles; neck length and bore follow the drawing.
• Blind and non-standard blind flanges: outside diameter, thickness, holes and facing all follow the drawing rather than a standard thickness table.
• Lap joint flanges: used with stub ends; stub ends and flanges can go on the same order.
• Facing: RF as standard; FF and RTJ to drawing.
• Grades: 304/304L, 316/316L, 310S, 321 and duplex 2205 and 2507, all stocked.

Process: forged flange blanks are prepared by grade and size and heat numbers are checked; faces, bores and outside diameters are turned, with large rings machined on large lathes; facings are machined and bolt holes drilled; then surface treatment, marking and inspection. Electropolishing is available as a matching service. See the parameters for welding neck (WN) flanges, long welding neck (LWN) flanges and non-standard blind flanges, and for selection see common flange types.

Quality and certificates

Every flange is marked, and the heat number traces back to the material certificate. PMI is available; outside diameter, bore, thickness, bolt holes and facing dimensions are checked; PT, UT, RT and hydrostatic testing are done when the order or drawing calls for them. EN 10204 3.1 certificates are available, and 3.2 certificates on request.

• China Special Equipment Production License (pressure piping components) TS2733H03-2027
• ISO 9001, ISO 14001 and ISO 45001 management system certificates
• Certificate of Quality Assurance System (PED 2014/68/EU Annex I 4.3 & AD 2000-Merkblatt W 0), issued by TÜV SÜD
• DNV and BV manufacturer approvals
• National High-Tech Enterprise, Zhejiang specialized and innovative SME, and work safety standardization certificates
• 10 authorized utility model patents

See the original certificates on the Certificates page.

Lead time and stock

Common grades are kept in stock. Non-standard flanges are scheduled for production in Lishui to the drawing. Lead time and minimum order are assessed by quantity and confirmed with the quote.

How to request a quote

Please list the flange type, standard and pressure rating (for example EN 1092-1 PN16), size and pipe OD and wall thickness, material, facing and quantity. Attach drawings for non-standard and large diameter flanges, and give neck length and bore for LWN. Note if you need 3.1 certificates or third-party inspection. The full checklist is on the forged stainless steel flanges page.

WhatsApp / phone +86 15210578298, email lucas@hbpipe.com, or use the form on the Contact page. We usually reply within one working day.

FAQ

Are HuaboPipe stainless steel flanges forged?

Yes. All HuaboPipe stainless steel flanges are formed by forging and pressing, including WN, SO, LWN, blind, non-standard blind and lap joint flanges.

What sizes can you make for non-standard flanges?

Outside diameter, thickness, bolt holes, neck length, bore and facing can all follow the drawing. Standard DN15–DN1200, larger to drawing up to DN3000.

What do I need to send for a non-standard flange?

A drawing or photos of a sample, plus material, pressure rating, facing and quantity. If some details are missing, send what you have and we will ask for the rest.

Can you make duplex 2205 and 2507 forged flanges?

Yes. 2205 and 2507 are stocked grades, and duplex flanges are also formed by forging and pressing, to ASTM A182 F51/F60 and F53.

Can you provide material certificates and third-party inspection?

Yes. EN 10204 3.1 material certificates are available, PMI is available, and third-party inspectors are welcome for in-process and final inspection.

What is the lead time for non-standard flanges?

Non-standard flanges are scheduled to the drawing. Lead time and minimum order are assessed by quantity and confirmed with the quote. Phone or WhatsApp +86 15210578298.