The Main Failures of the Valve

A marine valve is a common mechanical product in marine products. The failure of valves directly affects the normal operation of system equipment, and even leads to catastrophic consequences. Therefore, the types of valve failures are sorted out and analyzed to find out common failure modes and causes. It is very necessary to conduct a reliability test assessment on the stress source of failures of valves, and its effect on improving the reliability of the valve is also very obvious.
 
Types of failures of valves
The valve plays an important role in cutting off and throttling the medium in the pipeline where it is located. Various failures will occur for the valve when it is used. When a serious failure occurs, the valve will stop running. The specific failures include shell parts, drive parts of valve discs, bellows and fasteners being damaged. After a minor failure, the valve can continue to be used according to the functional requirements, but the efficiency is reduced. According to the failure type, the failures are divided into damage, imbalance, looseness, degradation, blockage and leakage. The common failures of the valve are shown in Table 1.
 
Main failures of valves
The analysis of failures of valves is as follows: The main causes of damage such as rupture and wear are the action of internal and external forces, strength and wear caused by long-term use, which can be attributed to material strength and long-term wear. Aging, blocking and other imbalances are caused by improper design and operation except for scouring. The main reason for leakages of sealing is caused by media impurities, media corrosion, cavitation, environmental factors, and improper design, which eventually lead to leakages. In summary, in addition to materials, design and process problems, the failure caused by the medium is the most commonly seen, mainly including corrosion, overpressure, leakages and other problems, followed by the damage caused by the long-term use of the valve and the strength under the action of internal and external forces. Leakages, corrosion and rupture are also the main forms of failures of valves and the focus of reliability test design research.
 
Table 1 A summary of common failures of valves