1.casting are stipulated as the requirement of GB/T9439 “Gray cast iron”
2.before machined, ageing heat treatment should be carried out in order to remove remaining stress.
3.the inside and outside surface of casting shall be smooth, sands, oxides and burrs on the unmachined surface shall be removed. It is unacceptable for any position if there are cracks, cover skip and other defect may impair the strength.
4.the tolerance displacement of rib should less than 5mm
5.the allowable tolerances of the diameter of the boltholes center circle of the coping flanges and the chord length of the adjacent boltholes shall be 0.6mm respectively. The allowable tolerance of the chord length of any two boltholes shall be +1 mm
6.defects such as radial penetrate sand blisters, air holes etc. that will interfere with the sealing properties are not allowed on the sealing surfaces of the flange.
7.the unspecified tolerance of the dimensions on the machined surfaces shall be as per grad m specified in GB/T1804. the tolerance of the general dimensions of the casting shall be as per grad CT13 specified in GB6414.
8.the radius of unspecified casting fillet is R4.
9.The test pressure should be 0.42 Mpa

1.铸造应遵循GB/T9439灰铸铁规范的要求

2.在进行机械加工前，应该进行时效热处理以去除残余应力
3.铸件的内部及外部应平滑，砂粒，氧化物及毛刺在进行机械加工前应该去除。绝对不允许有裂缝，表面起鼓及其它可能会降低强度的残疵。
4.偏移公差应该小于5毫米
5.顶部法兰螺栓孔中心圆直径公差和临近螺栓孔的弦长的公差应该分别控制在0.6毫米，任何两个螺栓孔弦长的公差应该在1毫米内。
6.法兰接面上，任何透光，砂眼，气孔等可能对密闭性能有影响的缺陷都是不允许有的。
7.未详细说明的机械表面尺寸的公差应该按照GB/T1804的梯度要求。铸件的总尺寸公差应该按照GB6414梯度CT13的要求
8.未详细说明的铸件内圆角是R4
9.检测压力是0.42兆帕