Home / Case / Experience / What are the performance requirements of an air exhaust valve?
Air exhaust valves are used in independent heating systems, central heating systems, heating boilers, central air conditioning, floor heating and solar heating systems and other pipeline exhaust.
When there is gas overflow in the system, the gas will climb up the pipe and eventually gather at the highest point of the system, and the exhaust valve is generally installed at the highest point of the system, when the gas enters the valve cavity of the exhaust valve gathered in the upper part of the exhaust valve, with the increase of gas in the valve, the pressure rises, when the gas pressure is greater than the system pressure, the gas will make the water level in the cavity fall, the float drops with the water level and opens the exhaust port; after the gas is exhausted After the gas is exhausted, the water level rises and the float rises with it, closing the exhaust port.
By the same token, when the system produces negative pressure, the water surface in the valve cavity drops, the exhaust port opens, because the external atmospheric pressure is larger than the system pressure, so the atmosphere will enter the system through the exhaust port to prevent the harm of negative pressure.
If you tighten the cap on the valve body of the exhaust valve, the exhaust valve stops exhausting, usually, the cap should be in the open state. The exhaust valve can also be used with the isolation valve to facilitate the maintenance of the exhaust valve.
1、The float of the exhaust valve is made of low-density PPR and composite material, which will not deform even under the immersion of high temperature water for a long time. It will not cause difficulties in float activities.
2、The float lever is made of hard plastic, and the connection between the lever and the float and the standoff is made of movable connection, so it will not rust and corrode during long-term operation, which will lead to the system not working and water leakage.
3、The sealing end part of the lever is supported by spring, which can be expanded and contracted accordingly with the movement of the lever to ensure the sealing in the case of non-exhaust.
When the exhaust valve is installed, it is best to install it together with the isolation valve, so that when the exhaust valve needs to be removed for maintenance, it can ensure that the system is airtight and the water does not flow out. Low-density PP material, this material will not change shape even under the immersion of high temperature water for a long time.
When the tube begins to fill with water, the plug stays in the open position for a large amount of exhaust, when the air is exhausted, the valve water, the float is floated, drive the plug to the closed position, stop a large amount of exhaust, when the water in the tube is normally transported, such as a small amount of air gathered in the valve to a considerable extent, the water level in the valve drops, the float then drops, at this time the air is discharged from the small hole, when the pumping machine stops, the water in the tube is empty or in case the tube When the negative pressure is generated, at this time, the plug head quickly open, inhaling air to ensure that the pipeline completely.
1. Air exhaust valve should have a large exhaust volume, when the pipeline empty tube filling can be achieved in a very short period of time to quickly exhaust back to normal water supply capacity.
2. Air exhaust valve in the pipe when there is a negative pressure, the piston should be able to quickly open a large number of rapid inhalation of outside air to ensure that the pipeline does not produce damage due to negative pressure. And in the working pressure can be a small amount of air collected in the pipeline to discharge.
3. The air exhaust valve should have a relatively high air shut-off pressure, in a relatively short period of time before the piston closes, there should be sufficient capacity to discharge the air in the pipeline to improve the efficiency of water delivery.
4. The water shut-off pressure of the exhaust valve should be no more than 0.02 MPa, and the exhaust valve can be closed at a lower water pressure, thus avoiding a large influx of water. e. Exhaust valve should use stainless steel floating ball (floating barrel) for opening and closing parts.
5. Air exhaust valve valve body should be equipped with anti-impact protection cylinder, to prevent a large amount of exhaust after the high-speed water directly impact the float (float bucket) and cause premature damage to the float (float bucket).
6. For DN ≥ 100 air exhaust valve using a split structure, consisting of a large number of exhaust valves and automatic exhaust valve to adapt to the use of pipeline pressure requirements.
Automatic air exhaust valve should use the compound lever mechanism, so that the buoyancy of the float can be greatly enlarged, and close the water level is low, impurities in the water is not easy to contact the sealing surface, the exhaust port will not be blocked, its anti-clogging performance can be greatly improved.
At the same time in the case of high pressure, due to the force of the compound lever, so that the float can be synchronized with the water level down, the opening and closing pieces will not be like the traditional valve is high pressure suction, so that the normal exhaust.
7. For high flow rates, frequent start-up pumps, DN ≧ 100 caliber conditions, in order to slow the impact of water flow, exhaust valve should be installed with a buffer plug valve. Buffer plug valve should be able to prevent a large amount of water spray but does not affect a large number of exhaust, so that the efficiency of water delivery will not be affected, and effectively prevent the occurrence of water hammer.