Blind flanges are critical flange types in piping systems for closing pipe ends, equipment openings, or reserved connection points. With no center bore, they can completely isolate media and withstand pressures equal to or even higher than the pipe itself. The nickel alloy blind flanges supplied by Hefei Tailan Metal Co., Ltd. are manufactured from high-quality nickel-based alloy forgings through multiple precision processes including forging, solution heat treatment, machining, drilling, and pickling/polishing. Featuring solid structure, high strength, excellent sealing performance, and superior corrosion resistance, they are specifically designed for applications requiring complete isolation such as pipe end closures, and equipment cleaning ports.
Supply Range
Nominal Diameter (DN/NPS): DN15 – DN600 (1/2 inch – 24 inches); Larger diameters negotiable
Pressure Class: Class 150, 300, 600, 900, 1500, 2500 (ASME)
Facing Type: Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ)
Flange Type: Blind Flange, Thickened Blind
Machining Precision: Sealing surface roughness Ra 3.2μm – 6.3μm (as per standard requirements)
Surface Condition: Machined, Pickled, Polished optional
Marking Method: Steel stamp marking on flange outer edge, conforming to MSS SP-25 or customer requirements
Special Notes:
- Blind flanges have no center bore, thickness is typically slightly larger thansame size welding neck flanges
- High pressure class blind flanges have significantly increased thickness, requiring consideration of material cost and weight
- Blind flanges with lifting lugs or special designs available for easy installation and removal
Strict Non-Destructive Testing
Every nickel alloy blind flange undergoes rigorous NDT inspection:
Penetrant Testing (PT) : Detecting surface-opening defects, conforming to ASTM E165 standard
Ultrasonic Testing (UT) : Detecting internal defects, conforming to ASTM A388 standard, particularly suitable for thick-walled blinds
Hardness Testing: Verifying heat treatment effectiveness and mechanical property uniformity
Multiple Facing Types Available
Various facing types available according to service conditions:
Raised Face (RF) : Most common, suitable for Class 150-2500
Ring Type Joint (RTJ) : For high pressure, high temperature, strict leakage prevention
Flat Face (FF) : For cast iron flanges or low pressure conditions
