A long weld neck flange LWN flange is a type of flange that has a long tapered neck that extends from the flange face to the pipe This longer neck provides more support to the pipe at the weld joint making it a more robust and reliable connection LWN flanges are typically used in highpressure and hightemperature applications such as in the oil and gas industry Technical Specifications Dimensions 12 to 24 in diameter The neck length is typically 15 to 2 times the flange diameter Materials Carbon Steel Stainless Steel or Alloy Steel Pressure ratings 150 psi to 2500 psi Temperature ratings 200F to 1000F Types RFFFRTJ LWN flanges are used in a variety of applications including Oil and gas industry Chemical industry Power generation Water treatment HVAC The benefits of using LWN flanges include Increased strength and reliability Longer service life Wider range of applications Easier to assemble and disassemble