Different of weld neck flange and slip on flange?

Different of weld neck flange and slip on flange?

Different of weld neck flange and slip on flange has some type:process flow,welding methods,form.
The weld neck flange is the pipe end and the wall thickness of the interface end, which are welded like two pipes, just like the pipes to be welded.
The slip on flange is a concave table which is slightly larger than the outer diameter of the pipe at the interface, and the pipe is welded inside.
Butt welding has better welding performance and less corrosion.

Slip on flange and weld neck flange are the welding methods of flange and pipe connection. When welding flanges, only one side welding does not need the inner mouth of the welded pipe and flange. The welding and installation of the welding flange requires double side welding of flange.
So slip on flanges are generally used for low and medium pressure pipes. Welding flanges are used to connect to middle and high pressure pipes. The flange of the butt welding is at least PN2.5MPa. The welding is used to reduce the stress concentration. The general welding flange is mostly called the neck flange and the nipple flange. Therefore, the installation cost, labor cost and auxiliary material cost of welding flange should be high, because more than one process.
The welding neck flange is not all both inside and outside welding, there is no special requirement in general and just outside welding, did not see the 1/2 “welding flange:”), the flat welding is better welding, because the pipe and flange good vertical, pipe will not slanting.