Storage tank safety accidents – breathing valves

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Accidents caused by improper selection of breather valves and inadequate maintenance later on are truly alarming! ! ! ! A breathing valve is an important device for maintaining pressure balance in storage tanks; when selecting one, the ventilation capacity of the valve should be calculated according to **standards. Working principle: Breather valves are used on liquid storage tanks. When the tank is being filled or emptied by a pump and the pressure reached by the valve disc reaches the set value, the valve disc moves to allow pressure or vacuum to be released, thereby preventing the tank from rupturing or collapsing. It also helps to reduce the evaporation and loss of the medium inside the tank. When the pressure inside the storage tank is in balance with atmospheric pressure, both the positive and negative valve discs of the breather valve fit tightly against their seats, maintaining a seal. When the pressure inside the tank exceeds atmospheric pressure (that is, an excessive positive pressure is generated), the high pressure inside the tank acts directly on the underside of the breather valve disc, overcoming the weight of the disc as well as the external air pressure acting on it, thereby opening the breather valve disc and allowing air to be discharged from the tank through the passage. When the pressure inside the tank is lower than atmospheric pressure (i.e., an excessive negative pressure is created), atmospheric pressure enters through the suction channel and acts directly beneath the suction valve flap. It overcomes the weight of the valve flap as well as the pressure inside the tank acting on that flap, thereby opening the suction valve flap and supplying pressure to the tank so as to maintain equilibrium between the tank pressure and atmospheric pressure. Daily maintenance of breather valves: 1. Conduct regular inspections on breather valves that are in use. Check whether the breathing valve is leaking, and inspect the sealing areas between the valve disc and the valve seat, as well as between the guide rods and their sleeves, for any oil or dirt. Any such debris should be removed, and it is also necessary to check that the opening mechanism functions smoothly and reliably. If everything is normal, then cover and tighten the valve cover. During maintenance, if any abnormalities such as scratches, wear, or corrosion are found on the valve disc, it should be replaced immediately or contact our company. 2. To prevent the breathing valve from failing to function properly over time due to the valve disc sticking to the valve seat, manual discharge tests should be conducted on the breathing valve regularly. 3. A usage card should be established for each breathing valve; this card shall contain the valve’s certification from the supplier, as well as copies of the records related to its repair, inspection, and adjustment. 4. Breather valves installed outdoors should be equipped with appropriate protective measures to prevent dirt such as rain, fog, dust, and rust from entering the valve. When the temperature is below zero degrees Celsius, necessary anti-freezing measures should also be taken to ensure the reliable operation of the breather valve. 5. If conditions permit, users must send the device to a breathing valve inspection station recognized by the Ministry of Labor for re-inspection every year; upon passing the inspection, it must be sealed and fitted with a certificate of compliance.