Uni Blind Flanges

Your Professional Uni Blind Flanges Supplier

Shanxi Hongkai Forging Co., Ltd. is located in China Energy Heavy Chemical Industry Base. Dingxiang County, the hometown of forging in Shanxi Province. Mainly produce flanges and forgings of various specifications. Application in piping installation, pressure vessel, equipment accessories.

Why Choose Us

Our Service
With strong technical force, advanced production technology, perfect quality inspection, and reliable after-sales service, it provides a basis for supervision and cooperation for many customers at home and abroad.

Our Certificate
The company Excellent Supplier of 2019 Safety production standardization certificate Quality management system certification.

Production Market
The products are mainly exported. It is exported to Europe, America and other countries and regions. The product quality is good, and the service is attentive. It is deeply appreciated and trusted by customers and users at home and abroad, and has won a high reputation. They have become one of the largest flange and forging suppliers in China.

Our Factory
Shanxi Hongkai Forging Co., Ltd. is located in China Energy Heavy Chemical Industry Base. Dingxiang County, the hometown of forging in Shanxi Province. Convenient transportation, abundant coal and power resources, fast communication and superior environment.

Surface Characteristics of Uni Blind Flanges

Sealing Performance:

A smooth surface is crucial for achieving an effective seal. When a blind flange is bolted onto a pipe, a smooth mating surface ensures that the gasket can make full contact. Gaskets are used between the flange and the pipe end to prevent leakage. A smooth surface reduces the chances of gaps or irregularities that could allow fluid or gas to escape.

Corrosion Resistance:

A smooth surface is less likely to accumulate dirt, debris, and corrosive substances. In industrial environments, pipes and flanges are often exposed to various chemicals and harsh conditions. When dirt and corrosive agents settle on a rough surface, they can create pockets where corrosion can start and spread.

Aesthetic Appeal:

In some applications, the appearance of the flange matters. For example, in architectural or decorative piping systems, a smooth - surfaced blind flange provides a more professional and polished look. It can enhance the overall aesthetic of the installation, making it more visually appealing.

Uni Blind Flanges Material & Grades

Stainless Steel Blind Flanges :
ASTM A182, F304, 304L, 304H, 316, 316L, 316Ti, 310, 310S, 321, 321H, 317, 347, 347H, 904L, SMO 254

Duplex & Super Duplex Steel Blind Flanges :
ASTM / ASME A/SA 182 F44, F45, F51, F53, F55, F60, F61 / Duplex 2205 – UNS S31803, UNS S32205 / Super Duplex 2507 – UNS S32750, UNS S32760

Hastelloy Blind Flanges :
ASTM B/SB564, Hastelloy B2 – UNS No. N10665, Hastelloy B3 – UNS No. N010675, Hastelloy C4 – UNS No. N06455, Hastelloy C22 – UNS No. N06022, Hastelloy C276 – UNS No. N10276, Hastelloy C2000 – UNS No. N06200, Hastelloy X – UNS No. N06002

Monel Blind Flanges :
ASME SB 564, Monel 400 – UNS No. N04400, Monel K500 – UNS No. N05500

Nickel Blind Flanges : Nickel 200 – UNS No. N02200 , Nickel 201 – UNS No. N02201

Titanium Blind Flanges :
ASTM B381 / ASME SB381, Grade 2 – UNS No. R50400, Grade 5 – UNS No. R56400

Alloy 20 Blind Flanges :
ASTM B462 / ASME SB462, Grade 2 – UNS No. N08020

Technical Specifications

Specification	Details
Standard	UNI (Ente Nazionale Italiano di Unificazione)
Flange Type	Blind Flanges (BL)
Pressure Ratings	PN6, PN10, PN16, PN25, PN40
Size Range	DN 15 to DN 1200 (custom sizes available on request)
Facing Types	Raised Face (RF), Flat Face (FF)
Design Features	Solid disc design for sealing pipeline ends, bolt holes per UNI standard, suitable for easy inspection and maintenance access
Applications	Oil & Gas, Water Treatment, Petrochemical, Power Generation, HVAC, Marine & Offshore, Fire Protection
Manufacturing Process	Forged and Machined in accordance with UNI dimensional tolerances

types of CNC machining

The surface finish of Uni Blind Flanges is determined by the manufacturing processes used.

Machining:

Machining is a common method for producing Uni Blind Flanges. During machining, the flange is cut, shaped, and finished using various tools. By controlling the machining parameters, such as the cutting speed, feed rate, and tool geometry, manufacturers can achieve different surface finishes. For a smooth surface, a fine - finishing tool and precise machining operations are required. On the other hand, if a rough surface is desired, coarser tools or different machining strategies can be employed.

Forging:

Forged Uni Blind Flanges often have a more uniform and denser structure. The forging process can also influence the surface finish. After forging, the flange may undergo additional finishing operations to achieve the desired smoothness or roughness.

Applications of UNI Blind Flanges

Industry	Application
Oil & Gas Industry	Used for isolating sections of pipelines, pressure testing, and system closures in high-pressure oil and gas transport lines.
Water Treatment & Distribution	Installed at the end of pipelines in filtration systems, pumping stations, and water distribution networks for secure shut-off.
Chemical & Petrochemical Plants	Provides reliable sealing for lines carrying corrosive chemicals or hazardous fluids, ensuring safety during maintenance.
Power Generation	Used in steam, gas, and hydro power plants to seal piping systems, enable inspection, and prevent leakage under pressure.
HVAC & Building Utilities	Supports sealed pipe terminations in chilled water, heating, and compressed air systems for commercial and industrial buildings.
Marine & Offshore Platforms	Ideal for end-closure of seawater and ballast piping systems, offering high resistance to corrosion and saltwater exposure.
Fire Protection Systems	Ensures secure isolation of fire suppression pipelines, hydrant lines, and sprinkler systems in emergency-ready installations.
Mining & Slurry Transport	Used at the ends of high-abrasion slurry pipelines in ore processing, mineral extraction, and tailing systems.

FAQ

Q: What are UNI Blind Flanges used for?

A: UNI Blind Flanges are used to seal the end of a piping system or pressure vessel. They are ideal for isolation, maintenance access, and pressure testing applications.

Q: What pressure ratings are available for UNI Blind Flanges?

A: UNI Blind Flanges are available in pressure ratings of PN6, PN10, PN16, PN25, and PN40, allowing for use in both low and high-pressure applications.

Q: What materials are UNI Blind Flanges made from?

A: They are manufactured using various materials, including Carbon Steel, Stainless Steel (304/316), Alloy Steel, Duplex & Super Duplex Steel, Inconel, Monel, Hastelloy, and Copper Nickel.

Q: Are UNI Blind Flanges suitable for high-pressure systems?

A: Yes, especially the PN25 and PN40 rated flanges, which are designed for high-pressure and high-temperature industrial systems.

Q: What industries commonly use UNI Blind Flanges?

A: They are widely used in oil & gas, chemical processing, water treatment, marine, HVAC, power generation, and fire protection systems.

Q: Can UNI Blind Flanges be customized?

A: Yes, we offer customized UNI Blind Flanges in terms of dimensions, drilling, face types, and materials to meet specific project requirements.

We're well-known as one of the leading uni blind flanges manufacturers and suppliers in China. If you're going to wholesale high quality uni blind flanges with competitive price, welcome to get more information from our factory. Also, customized service is available.

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