Compared with other mechanical manufacturing process, multi control valve manufacturing process has the following features:
1.The valve of blank manufacturing technology and inspection technology is more complex.
  The valve is the structure that complex casting billet the thin shell parts. More  way the surface is bright and clean, casting requirements characters clear, especially the defects of dense. In order to satisfy the above-mentioned requirements, should take a series of process in casting measures, if choose high refractoriness modelling materials and control sand water, multi control valve should be a real layered model to ensure a sand hardness, a reasonable pouring cap mouth and control system casting speed and temperature, etc. Many road because of technology to demand higher valve, the valve of blank casting process is more general casting complex.
  In addition, the blank body valve in size, multi control valve position precision and look outside, some still be microstructure, mechanical properties, corrosion resistance and nondestructive flaw detection and so on many kinds of inspection, the inspection process of the valve are complex

2.Difficulty mechanical processing
 Because there are so many kind of the raw materials, multi control valve of cast iron, carbon steel in addition to the most of its high strength, corrosion resistance and high hard material the cutting performance are bad, it's difficult to meet the prescribed parts machining accuracy and surface roughness. Many paths valve and the geometry of the valve sealing surface shape precision and surface roughness is demanding, so more increased valve mechanical processing difficulty.
 At the same time, the valve material cutting performance not good, much to the way the valve and processing methods, cutting tool materials, cutting dosages, process equipment and other aspects, brought a lot of new problems.

3.Valve parts in the machine installation more difficult
 The major parts of the valve structure, shape is more complex, more road some parts of the thin wall, slightness piece, rigid poor. In the machine processing, positioning and clamping difficult, so often require complex special jig.
 Some valve parts, positioning of the low precision, the surface roughness is higher, sometimes even more road valve adopts the processing surface positioning. Many paths valve and the place such as the sealing surface by processing precision and surface roughness requirements are very high, so difficult machining quality guarantee. Therefore, in order to meet the needs of the craft, more often must improve the way of positioning accuracy and reduce the surface roughness, or in the processing surface processing the yankees face positioning, increasing the complexity of the valve manufacturing process.