Valve flap can all be made of metal can also be embedded in the metal on leather, rubber, or synthetic coverage, depending on the use of performance requirements.
阀瓣可以全部用金属制成，也可以在金属上镶嵌皮革、橡胶、或者采用合成覆盖面，这取决于使用性能的要求。
2
Its comprehensive coverage focuses on detection of defects in all types of metal castings.
它的广泛报导集中在所有类型金属铸件的探伤。
3
The contact window formed by using said method possesses excellent metal aluminium graded coverage rate, and can make electric connection reliable, and do not increase cost.