Long Weld Neck Flanges (LWN)
At first distributors, we supply Long Weld Neck (LWN) flanges designed for high-pressure, high-temperature, and critical service environments. Engineered for strength and reliability, lwn flanges provide a smooth bore transition and superior stress distribution—making them ideal for demanding industrial applications.
Items We Offer:
| Size range: | 1/2" - 48" Diameter |
| Face types: | Raised face, rtj |
| Class: | 150 through 2500 |
| Carbon steel: | A105, a350 lf2 |
| Stainless steel: | 304, 316 |
| Special alloy: | Inconel, monel, duplex, super duplex, |
What is a Long Weld Neck Flange?
A heavy barrel flange is a specialized flange with a thick, extended hub (barrel) that provides additional reinforcement beyond standard weld neck or Long Weld Neck designs.
These flanges are commonly used where:
- Smooth transition from flange to pipe reduces turbulence and erosion
- Superior stress distribution under pressure and thermal cycling
- Ideal for high-integrity systems where failure is not an option
- Often used in place of a weld neck flange + pipe spool
- Specifications & standards
We supply lwn flanges manufactured to meet industry standards:
These flanges are commonly used where:
- Oil & gas (upstream and downstream)
- Petrochemical facilities
- Refineries
- Power generation
- Lng and cryogenic systems
- High-pressure piping systems
- Nozzle connections on pressure vessels
Why use Long Weld Neck instead of standard flanges?
| Feature: | standard weld neck | long weld neck |
| Neck length: | short | extended |
| Stress handling: | good | superior |
| Flow transition: | good | excellent |
| Use case: | general service | critical/high-stress systems |
Custom machining & value-added services