This slip on weld flange is according to JIS standard.It is a flange system made by Japan. This kind of flange include lots of specification,like SOP, SPH, Blind flange, plate flange, welded neck flange, etc.
Slip on weld flanges are slipped over the pipe and welded (usually both inside and outside) to provide strength and prevent leakage. Slip-on Flanges are at the low cost end of the scale, and do not require high accuracy when cutting the pipe to length. These SO flanges can sometimes have a boss or hub, and can be made with a bore to suit either pipe or tube.
The material of the flanges is carbon steel. The flange can connecting pipes, valves, pumps and other equipment to form a pipework systems. It is the machinery, petroleum, chemical, water, electricity, shipbuilding sectors piping systems and devices most widely used pipe fittings.

nconel 600 Inconel 601 Inconel 617 Inconel 625LCF Inconel 686
Inconel 690 Inconel 718 Inconel 725 Inconel X-750

Hastelloy C-276 Hastelloy C Hastelloy C-22 Hastelloy C-2000
Hastelloy G Hastelloy G-30 Hastelloy B Hastelloy B-2
Hastelloy B-3

Monel 400 Monel 401 Monel 404 Monel R405 Monel K-500

Nickel 200 Nickel 201 Nickel 205

Nimonic 80A Nimonic 90 Nimonic 105 Nimonic 115 Nimonic 901

Udimet 188 Udimet 720 Udimet R41 Udimet 300