I. Overview of breathing manholes
The breathing manholes are installed in safety emergency ventilation devices on the top of the storage tanks of petroleum and chemical materials. It is usually used in conjunction with a breathing valve to prevent pressure relief or gas inhalation when a sudden overpressure or vacuum occurs in the tank due to an accident. Breathing manhole is an all-weather sealing structure. The weight is used to adjust the opening and closing of the suction valve flap and the pressure relief cover. It has the characteristics of constant pressure discharge, constant pressure suction, flexible opening and closing, safe and reliable.
Second, the working principle of breathing manhole
Under normal working conditions of the breathing valve, the breathing manhole is kept substantially sealed and the tank is at normal pressure. When the normal operation of the breathing valve can not meet the sudden overpressure of the tank pressure due to accidental reasons, the pressure relief cover of the HXRK breathing manhole is automatically opened, and the emergency pressure is released to keep the pressure inside the tank normal; when the pressure in the tank is sharply reduced When pressure or ultra-vacuum, the suction valve will open to the atmosphere and maintain normal pressure in the tank to protect the tank. The difference is that the HXRK type can be inhaled and discharged; while the XYRK type can only be discharged and cannot be inhaled. Please distinguish it when selecting the model.
Third, the breathing manhole technical performance
1. Operating pressure: positive pressure: 1961Pa (+200mmH20), negative pressure: 392Pa (-40mmH20) or positive and negative pressure can be specified by the user.
2, the use temperature: -30 ° C ~ +60 ° C