How would exhaust pneumatic valve sealing surface of damaged

select material, equipment, use and maintenance service elements such as bad provoked. The so-called natural damage, refers to the pneumatic valve under normal working conditions and wear, medium of exhaust pneumatic valve sealing surface shall not prevent formation damage such as corrosion and erosion. As these do not resolutely prevent the loss of billet are called natural damage.
the cause of formation damage, boil down following several:
. Exhaust pneumatic valve sealing surface machining quality is bad: the main appearance in exhaust pneumatic valve sealing surface cracks, porosity and defects such as holes, were due to improper overlaying welding and heat treatment standards selection, operation in the process of the overlaying welding and heat treatment and adverse provoked, pneumatic valve sealing surface through the high or low, because the material is wrong or improper heat treatment provoked, exhaust pneumatic valve sealing surface uneven hardness, corrosion resistance, is largely due to the underlying metal in welding process blow to the above, dilute the leading of pneumatic valve sealing surface alloy components. There also have a design problem.
　　. Improper selection and operation bad provoked by the damage: main appearance without according to the working condition choose pneumatic valve, pneumatic valve when the truncated throttling use pneumatic valve, close the pressure is too large and close too fast or closed lax, the exhaust pneumatic valve sealing surface erosion and abrasion.
　　. Device is not lack of maintenance by exhaust pneumatic valve sealing surface work abnormal, pneumatic valve, in spite of premature damage exhaust pneumatic valve sealing surface.
　　. Chemical corrosion medium, the medium around the vent pneumatic valve sealing surface, in does not produce current situation, the medium directly with exhaust pneumatic valve sealing surface chemistry, corrosion package is exhaust pneumatic valve sealing surface.
　　. Electrochemical corrosion study: exhaust pneumatic valve sealing surface contact each other, exhaust pneumatic valve sealing surface contact with close parts and pneumatic valve body, and the concentration of the medium is poor, poor oxygen concentration, will generate an electrical potential difference, electrochemical corrosion of anode on the one hand, the pneumatic valve sealing surface corrosion.