Blind Flange

Blind flange is a form of flange connection, which is actually a flange without a hole in the middle. The main function is to block the end of the pipeline, and then it can be convenient to remove debris in the pipeline during maintenance. Therefore, for this usage scenario, Longan R&D personnel have their own unique insights on the product!

Longan's flange solves several core problems

1. Ultra-high pressure sealing performance

Burst pressure: ≥3 times the rated pressure. After API 6A test, the actual measured burst value of Class 600 flange is 1920 bar, which fully meets the industry-leading standards.

Sealing leakage rate: blind flange plate helium mass spectrometer leak detection ≤1×10⁻⁹ mbar·L/s, exceeding the highest grade A standard of ISO 5208

2. Customized and flexible response

Product size coverage: DN15~DN3000 (support non-standard wall thickness/sealing surface type)

Carbon steel/stainless steel/duplex steel/Hastelloy alloy, hardness range HB150~HB350

3. Adaptability to extreme working conditions

Temperature range -196℃~650℃, corrosion resistance: passed NACE MR0175 acid environment certification, H₂S tolerance concentration ≥5000 ppm

4. Structural strength increased by 40%

Material strength: The tensile strength of the blind flange plate forged steel we produce is ≥485 MPa (35% increase compared to cast flanges)

5. Revolutionary installation efficiency Quick disassembly and assembly design: With the hydraulic clamp, the single installation time is less than 8 minutes, which is three times shorter than the traditional 25 minutes!

At present, Longan flange has high production efficiency and fast logistics. Generally speaking, it takes about 12-16 days from Shanghai and other ports to reach ports around the world, and the latest transportation time can be controlled within 25 days. You can place an order with confidence!