Green Sands casting, Made in Grey or Ductile Iron, pneumatic shell Cover, Thepressure resistance in water is 4.2Mpa and in Liquid ammonia is 2.8Mpa.Green Sands casting, Made in Grey or Ductile Iron, pneumatic shell Cover, Thepressure resistance in water is 4.2Mpa and in Liquid ammonia is 2.8Mpa.