What is difference between weld neck flange and slip on weld flange?

Answer 1

http://www.tubecraftflange.com/products/slipon.htm

TubeSlip-On Flanges are probably the most common type of flanges in the industry and are ideal for lower pressure applications. You do not have to specify the pipe schedule when using slip-on flanges due to the fact that its inside diameter is determined by the outside diameter of the pipe. This outside diameter of the pipe does not change for the different schedules. This often makes these easier to stock for vendors. Fabricators also like the fact that these flanges are slightly easier to align than weld neck flanges. They also are slightly easier to cut pipe to the proper length for. They can be used for high temperature and pressure applications but are not generally recommended as compared to other types of flanges. ASME B16.5 Code limits their usage in the 1500#-2500# (lbs.) weight classes.

Answer 2

There are some difference between ANSI Stainless Steel Welding Neck Flange and ANSI Stainless Steel Slip On Flange:

1. Welding forms are differernt. Welding Neck Flange can be radiographed but slip on flanges can not. The form of welding betweent welding neck flange and pipe is circular weld , but the between slip on flange and pipe is fillet weld.

2. Materials are different. The Welding neck flange’s material is usually made of forged steel parts by machining. While the Slip On Flange’s material that conforms to the common requirements of the steel plate thickness and made by machining.

3. Nominal pressures are different. The nominal pressure of the Welding neck flange is 1-25MPa, and the grade is higher. Nominal pressure of slip on flange is 0.6-4MPa grade, compared with the butt welding neck flange, the pressure level is relatively low, the ability to adapt to stress will be slightly lower.

4.Connection modes are different. Welding neck flange is usually flange butt with pipe, Slip On Flange is normally fillet with pipe, at this point is the biggest difference is on the structure.

Answer 3

Weld neck flanges have small or long neck like extension at its end , but the slip on flange has not any extension on its end.