Long Weld Neck Flanges

Why can Long Weld Neck Flanges resist corrosive environments?

1. Material performance

Comparison item 316 stainless steel 304 stainless steel Improved by 300%

PREN value >25 ~19 Pitting resistance +31%

Test standard: ASTM G48 Method A (5% NaCl, 35°C), flange surface pickling and passivation treatment

Molybdenum content 2.1~3.0% ≤0.75% Key corrosion resistance element content several times

Salt spray test 1,000 hours no pitting 200 hours rust Life increased by 3 times

2. High temperature and high pressure performance

Usable temperature range: -196°C to 800°C (short-term peak), if it is 316L low-carbon type, anti-sensitization is better.

Pressure-temperature rating: In accordance with the latest version of ASME B16.5, Class 150 flanges withstand 20 bar at 38°C and still maintain 15 bar at 300°C.

3. Applicable scenarios for welding

Type Structural features Advantageous scenarios Applicable pressure level

Lap joint Flange ring and short joint are separated Frequent disassembly/corrosive media Class 150~900

Socket weld Pipe inserted into socket for welding Small diameter (DN≤80mm) clean fluid Class 300~600

Weld neck Conical neck smooth transition High pressure/vibration/heat cycle pipeline Class 300~2500

User question answering (FAQ)

Q1: Is 316 welding flange suitable for high pressure?

A: Only clean fluids with DN≤80mm and Class≤600 are recommended. For high-pressure pipelines, please use Long Weld Neck Flanges to make stress distribution better.

Q2: How to verify the authenticity of the material?

A: We provide third-party spectral test report (PMI test)

MTR material traceability code (scan code to verify)

NACE MR0175 certification (anti-sulfide stress cracking)

Q3: How to choose 316 and 316L?

A: 316L (carbon content ≤ 0.03%) is a must for welding scenarios to avoid intergranular corrosion in the heat-affected zone; Long Weld Neck Flanges can be selected for non-welded parts.

Why choose us?

Cost optimization: Compared with small-batch purchases by peers, large-scale forging reduces unit prices by 15%.

Inventory depth: Full sizes from DN15 to DN600 are always available, and can be shipped within 72 hours.

Data support: Free pressure-temperature calculation tools are provided.

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