How to solve the deformation of pneumatic valve pneumatic brake seat

pneumatic valve is a kind of widely used pneumatic brake valve, and is mainly used to connect truncated medium pipeline. According to different packing element forms of brake pneumatic valve can be divided into pneumatic wedge gate valve, pneumatic valve, wedge double parallel brake disc brake pneumatic valve, pneumatic valve parallel double disc brake, etc. Brake pneumatic valve can be used the way, also can adopt compulsory seal. Due to the forced sealing reliability, use common in petrochemical industry.
pneumatic wedge gate valve by pneumatic valve wedge plate on two pneumatic seat sealing surface and the two seal face of trendy closely integrated to achieve sealing wedge, the wedge into the process of the sealing surface to withstand large extrusion pressure and friction, so the sealing surface are prone to damage and cause leakage. To improve the reliability of pneumatic wedge gate valve and prolong its service life, many scholars from the aspects such as material, structure and stress has been studied, but the pneumatic valve wedge brake failure accidents still happen, some even in the use of one or more times after failure happens, brought great potential safety hazard to production. In this paper, we study the failure of the brake pneumatic valve as XFF - Pneumatic wedge gate valve, the first time at the scene of the oil field water pressure test is produced after failure. Trial staff close brake after pneumatic valve to open, close the gate again after pneumatic valve pneumatic valve failed to find gate as water. This paper, taking the brake pneumatic valve failure accidents as the research object, analysis of brake failure reasons of pneumatic valve, explore the measures and methods to avoid such accidents.

macro analysis after pneumatic valve body found open gate lock pneumatic valve inside A pneumatic seat has large deformation, A pneumatic valve seat local inner concave, severe deformation, lower left side part is out of and the ontology of thread engagement.
A pneumatic seat appearance appearance as shown in figure, visible on the surface of I, II and III three broken zone, boundary surface hardening layer and base is obvious; Area. Both the crack from the inside circle through the round outside, near the surface hardened layer and the substrate has a smaller residual displacement in the direction of pneumatic valve plate to open; Area o broken seriously, near a circle inside crack surface hardening layer falls off, the surface is a circle from the medial through to round the outside of the crack, crack parallel to the direction of pneumatic valve plate to open, near the surface hardened layer and the substrate has a pneumatic valve plate to open the residual displacement direction; III crack were ° triangle area, since the round inside two central extension phase transfer in the end, on the inside circle cracks in surface hardening layer falls off, near the surface hardened layer and the substrate has a smaller residual displacement in the direction of pneumatic valve plate to open.
A pneumatic valve seat face zone II and zone III serious fragmentations, regional distribution of II FaSheZhuang small crack, according to extrusion shape, area II still visible from the inside circle to round the outside to the inside circle point arc line extrusion traces change
B pneumatic seat formed elliptic, including the short axis parallel to the direction of pneumatic valve plate to open. Pneumatic valve plate A surface contact with A pneumatic valve seat seal faces, exterior appearance as shown in figure, area. Chamfering in bonded metal grains. Pneumatic valve plate B surface is in good condition, no damage.

pneumatic valve seat surface microcosmic analysis to electron microscope observation of region II, the crackle radiated extrusion morphology for the center with des, so regional o by local compression. On the regional level II in microscopic observation found that the friction damage morphology.

a) improvement measures and effect Improve the processing technology of the pneumatic valve plate two ring sealing surface, while guarantee the two seal face flatness to ensure that the two seal face symmetry.
b) Install the new pneumatic valve seat, adjust the pneumatic wedge space between two seating surface to the pneumatic valve plate moves to reserve position to achieve good sealing.
c) To strengthen the use of pneumatic valve test, before and after using the gate to avoid a damage or other defects of the pneumatic brake valve into the field use.
d） After installing a new pneumatic valve plate and seat back brake pneumatic valve for water pressure test, the result qualified, late oil field of the pneumatic valve opening and closing times did not find brake pneumatic valve leakage or damage. Conclusion

) Pneumatic valve plate on both sides of the wedge surface flatness is poor, on both sides of the plane with the center surface asymmetry, seriously affected the pneumatic valve plate and seat sealing performance, and causes in the process of the pneumatic valve plate wedging and open to the pneumatic valve seat surface produce too much local extrusion pressure and friction.
） A pneumatic seat and B lead to inappropriate position of pneumatic valve seat assembly wedge between the two sealing surface of the space is too large, pneumatic valve plate moved to the desired location and pneumatic seat cannot produce A tight seal.
） A pneumatic seat and B pneumatic seat by pneumatic valve plate extrusion pressure and the friction effect lead to deformation.
） The improved aerodynamic seat to satisfy the use requirement.