Gas injection micro-discharge valve

I. Product Introduction:
   The micro-exhaust valve with gas injection, also known as the vacuum breaker, is used for pipeline exhaust. It is widely applied in independent heating systems, central heating systems, heating boilers, central air conditioners, floor heating, and solar heating systems, etc. Since water usually contains a certain amount of dissolved air, and the solubility of air decreases with increasing temperature, during the water circulation process, gas gradually separates from the water and aggregates to form large bubbles or even gas columns. Therefore, as long as there is water make-up, gas will be generated frequently. At this time, the exhaust valve is needed to discharge the accumulated gas in the pipeline to ensure unobstructed flow of the pipeline medium and prevent the hazards caused by negative pressure in the pipeline due to accumulated gas.

II. Product Features:
1. The float is made of low-density PPR and composite materials, which will not deform even when immersed in high-temperature water for a long time, thus avoiding difficulty in float movement.
2. The float lever is made of hard plastic, and the connection between the lever and both the float and the support is a movable connection, so it will not rust during long-term operation, which would otherwise cause system failure and water leakage.
3. The sealing end face of the lever is supported by a spring, which can expand and contract accordingly with the movement of the lever, ensuring sealing performance when exhaust is not needed.

III. Product Principle:
It is generally installed at the highest point of the system. When gas overflows from the system, it will rise along the pipeline and eventually gather at the highest point of the system. When gas enters the valve cavity of the exhaust valve and accumulates in the upper part of the valve, as the gas in the valve increases, the gas pressure rises above the system pressure, causing the water level in the cavity to drop. The float drops along with the water level, thus opening the exhaust port. After the gas is exhausted, the water level rises, and the float rises accordingly, closing the exhaust port. By the same token, when negative pressure occurs in the system, the water level in the valve cavity drops and the exhaust port opens. Since the external atmospheric pressure is higher than the system pressure at this time, air will enter the system through the exhaust port, preventing the hazards of negative pressure.

IV. Performance Requirements:
1. The exhaust valve should have a large exhaust capacity. When the pipeline is filled with water from an empty state, it can quickly exhaust gas and restore normal water supply capacity in a very short time.
2. When negative pressure occurs in the pipeline, the piston of the exhaust valve should be able to open quickly and inhale a large amount of external air rapidly, ensuring that the pipeline will not be damaged by negative pressure. Moreover, it should be able to discharge the trace air accumulated in the pipeline under working pressure.
3. The exhaust valve should have a relatively high air-closing pressure. Within a short time before the piston closes, it should have sufficient capacity to exhaust all the air in the pipeline, improving water transmission efficiency.
4. The water-closing pressure of the exhaust valve should not exceed 0.02 MPa, meaning the exhaust valve can close under relatively low water pressure, thus avoiding massive water gushing.
5. The exhaust valve should use a stainless steel float (float bucket) as the opening and closing component.
6. The valve body of the exhaust valve should be equipped with an anti-impact inner cylinder to prevent high-speed water flow after large-scale exhaust from directly impacting the float (float bucket) and causing premature damage to it.
7. For exhaust valves with DN ≥ 100, a split structure is adopted, consisting of a large-exhaust valve and an automatic exhaust valve, to meet the pressure requirements of the pipeline. The automatic exhaust valve should use a compound lever mechanism, which can greatly amplify the buoyancy of the float, and has a low closing water level, so impurities in the water are less likely to contact the sealing surface, and the exhaust port will not be blocked, greatly improving its anti-blocking performance. Meanwhile, under high pressure, due to the boosting effect of the compound lever, the float can drop synchronously with the water level, and the opening and closing component will not be sucked by high pressure as in traditional valves, thus ensuring normal exhaust.
8. For working conditions with high flow rate, frequent pump start-ups, and DN ≥ 100, to mitigate water flow impact, the exhaust valve should be equipped with a buffer plug valve. The buffer plug valve can prevent massive water spray without affecting large-scale exhaust, so water transmission efficiency will not be impaired, and water hammer can be effectively prevented.

V. External Dimensions: