Nihan,ball valves, in theree piece unique sandwivh type design, sutable for replacing seat on line . Interchangeability of end connection and spares, full borve / regular bore positively retained,back seated stem. Valve are in accordance with bs:5159/5351. Mss-sp72. Ansi b16. 34screwed connection in bsp/int type socket weld connection as per ansi b16. 11 and buttweld as per b16. 25 material of construction in ci. Ms. Cs. Ss304. Cf8. Ss316 cf8m and other alloy sreels. Size:1/2" to 2" bigger size available on request.