【Topics for Week 4 in the Piping and Valves Section】The difference between breather valves and safety valves
Thread Content
This post was last edited by security on 2011-1-27 10:20. The difference between a breathing valve and a safety valve
Their uses and application scenarios are different. Safety valves are generally used in pressure vessels to prevent the equipment or system from experiencing overpressure, while breather valves are typically used in vessels at atmospheric pressure; they are installed on vent pipes to accommodate minor changes in pressure within the tank and serve that purpose of breathing.
Vent valves and safety valves differ primarily in terms of pressure: those with a pressure below 1 MPa are vent valves, while those with a pressure above 1 MPa are safety valves. Additionally, a breathing valve can not only release air but also draw in air, whereas a safety valve is only for releasing air. The two types of valves differ significantly in design and manufacturing.
The sections on the 2nd and 3rd floors have been largely covered. The 2nd floor discusses the different scenarios in which they are used, while the 3rd floor explains the differences in structure and function. I completely agree; that’s indeed how it is in reality
A breather valve is an important accessory for ensuring the safety of oil tanks; it is installed on the top of the tank and consists of a pressure valve and a vacuum valve. Its function is, under normal circumstances, to maintain the integrity of the oil tank and to reduce oil evaporation losses to a certain extent. And when necessary, it can automatically ventilate to regulate the pressure inside and outside the oil tank, thereby ensuring its safety. A safety valve is a valve used for safety protection; its operating element remains in a closed state under external forces. When the pressure of the medium inside a device or pipeline rises above the specified value, the valve opens automatically, allowing the medium to be discharged outside the system thereby preventing the pressure from exceeding the set limit. Safety valves belong to the category of automatic valves and are primarily used in boilers, pressure vessels, and pipelines to ensure that pressure does not exceed specified levels, thereby playing a vital role in protecting both human safety and the proper operation of equipment.
A safety valve only serves for venting; a breathing valve can both vent and draw in air； Safety valves are used to prevent overpressure, while breather valves prevent both overpressure and negative pressure inside.
Reply to 1# 396956424: The breathing valve is primarily used to maintain normal pressure inside the tank, preventing overpressure or excessive vacuum conditions, and it also helps reduce the evaporation of liquid within the tank. GB 50160 stipulates that fixed-roof tanks for Class A and Class B liquids shall be equipped with flame arresters and breather valves. A safety valve prevents explosions by preventing system pressure from exceeding the design pressure of containers and pipes. The uses are a bit different.
Breath valves can be used at normal pressure, as is common in gas stations, while safety valves are used for high pressures
The main difference is that a safety valve operates in emergency situations, while a breather valve can discharge and intake air regularly.
A breather valve is primarily used to maintain pressure balance inside the container, preventing overpressure or undervacuum conditions, and it also helps reduce the evaporation of liquids within the tank. According to GB 50160, fixed-roof tanks for Class A and Class B liquids shall be equipped with flame arresters and vent valves. There is also a type of vent valve known as an \"explosion-proof flame-arresting vent valve\", which combines the explosion-proof and flame-arresting functions of a flame arrester with the function of a vent valve in balancing the pressure inside the tank; it helps to prevent explosions, suppress flames, and balance the pressure to reduce the evaporation of the substances contained in the tank. A safety valve prevents explosions by preventing system pressure from exceeding the design pressure of containers and pipes. Its purpose is different from that of a breathing valve.
That brother could upload a diagram of the breathing valve so that we can all see what the differences are.