Pneumatic valve steam boiler safety & amp; # 8203; Spring force analysis

security pneumatic valve is one of the main safety accessories of steam boiler, as a kind of important protection function of pneumatic valve, pneumatic valve was safe and its widely used in all kinds of steam boiler pressure vessel and pipeline system, the pressure container reaches maximum pressure to bear, can automatically open induction, excess the medium pressure container, and the discharge after can be automatically shut down, to ensure the pressure vessel can allow the scope of the pressure of safe and reliable operation, avoid steam boiler major security incidents.

the normal work of the steam boiler safety pneumatic valve, not only relationship between the steam boiler pressure vessel safety normal use, such as more directly related to the life and property safety of the masses, therefore, pneumatic valve spring common faults of steam boiler safety must be attached great importance to, and in time. In the following paragraphs, the steam boiler safety pneumatic valve spring failure reason was analyzed and discussed.

steam boiler safety pneumatic valve spring assembly by MPa down normal stress, pneumatic valve fully open, it will be MPa pressure when the pipe around the steam temperature of ℃ change, because the spring is in the closed cases, and in the upper part of the pneumatic valve body, so it's temperature slightly lower. The factors causing the failure of the steam boiler safety pneumatic valve spring is flabby, temperature difference between failure and spring material itself, the main factor is the steam boiler safety pneumatic valve spring, corrosion caused by the center of the effect of load and impact load.

pneumatic valve steam boiler safety & #; Spring force analysis

steam, axial or radial load boilers used on the safety of the pneumatic valve spring, most for cylindrical. By calculation, safety by axial spring pneumatic valve spring subjected to axial or radial load is applied, the deformation, the shear stress is inversely proportional to the spring wire diameter; When spring in use from corrosion, spring wire diameter smaller, spring deformation, shear stress increases, resulting in spring failure.
and influenced by the load center
in the operation of the steam boiler, safety of pneumatic valve to discharge steam overpressure on a regular basis. After the exhaust steam, pneumatic valve rod deflection, result in security pneumatic valve leakage and the spring under the center load and eccentric, resulting in a circular spring security stress value. That security is inversely proportional to the stress and the load eccentricity, disable security pneumatic valve spring, shorten service life.
and is affected by impact load
in the operation of the steam boiler, safety frequent pulse pneumatic valve, exhaust generate large impact velocity, the spring of the first three ring under impact load first, absorb more impact energy. Unable to quickly and effectively to impact load is transmitted to the back of the spring coil. In the first three produce plastic deformation and failure.