In industrial fluid control systems, valve sealing surfaces play a key role in cutting off, connecting, regulating, distributing, separating and mixing media. However, since the sealing surface is often in direct contact with the medium, it is susceptible to corrosion, erosion and wear, resulting in damage. Understanding the causes of sealing surface damage and taking appropriate measures are essential to ensure valve performance and extend service life. The following is an analysis of the causes of valve sealing surface damage and enhancement strategies for users.
Causes of sealing surface damage
Sealing surface damage can be divided into two categories of man-made damage and natural damage.
Man-made damage
Man-made damage is mainly caused by design defects, lack of manufacturing precision, improper material selection, installation deviations, improper use and poor maintenance and other factors. For example, the sealing surface cracks, pores and slag and other defects that may occur, often due to improper operation or improper selection of specifications in the surfacing and heat treatment process. In addition, problems such as excessive or low hardness of the sealing surface, uneven hardness and lack of corrosion resistance may also be related to incorrect material selection or improper heat treatment.
Natural damage
Natural damage is the valve under normal operating conditions due to media corrosion of the sealing surface and erosion and other damage. This damage is unavoidable, but can be mitigated by reasonable material selection and design.
Specifically, the causes of damage to the sealing surface can be summarized as follows:
Poor processing quality: Defects on the sealing face, such as cracks, porosity and slag entrapment, may be caused by operational errors during the surfacing and heat treatment process. In addition, sealing surface hardness problems may also be related to improper material selection and heat treatment.
Improper selection and poor operation: failure to select the appropriate valve according to the working conditions, or the use of the cut-off valve as a throttle valve may lead to the sealing surface is subjected to excessive closing specific pressure and erosion. Incorrect installation and poor maintenance can also lead to improper sealing surface work, thus accelerating the damage.
Chemical corrosion: the medium directly with the sealing surface of the chemical action, or due to electrochemical corrosion potential difference, will lead to sealing surface corrosion.
Erosion: media flow on the sealing surface of the abrasion, scouring and vapor corrosion, will lead to localized damage. This damage in the medium contains floating particles, high-speed flow or mixed flow is particularly obvious.
Mechanical damage: sealing surface in the process of opening and closing may be damaged due to abrasion, bruising and crushing. In addition, high temperature and high pressure atomic interpenetration of the adhesion phenomenon, as well as the valve closure process of the valve flap on the sealing surface of the bruises and injuries, will also lead to sealing surface damage.
Fatigue damage: long-term use and alternating loads, the sealing surface may appear fatigue cracks and peeling. For materials such as rubber and plastic, long-term use may also lead to aging phenomenon.
Enhancement Strategies
In order to improve the quality and service life of the valve sealing surface, the following strategies can be taken:
Selection of appropriate sealing surface materials: According to the characteristics of the medium and working conditions, select the appropriate sealing surface materials.
Adopt reasonable sealing structure: design a reasonable sealing structure to reduce the medium on the sealing surface of the erosion and corrosion.
Optimize the processing method: improve the processing quality of the sealing surface to ensure that the surface finish and hardness meet the requirements.
Strengthen the maintenance and repair: regular inspection and maintenance of the valve, timely detection and repair of potential problems.
Valve sealing surface damage causes and enhancement strategies
