Electric Flanged Ball Valve

During operation, the RTO furnace is in a slightly negative pressure state. The outer side of the RTO dedicated valve is connected to the flue gas outlet pipe, with an area temperature of up to 300 ℃; The outer side of the low-temperature side directional valve is connected to the flue gas inlet pipe, and the regional temperature can reach 200 ℃. The exhaust gas in the furnace has a certain degree of corrosiveness. During equipment operation, the RTO dedicated valve opens and closes every half minute, with frequent actions.

The RTO specialized valve is in direct contact with the sealing end face to achieve sealing. After the valve disc is closed, due to low machining and assembly accuracy, the sealing is not tight.Exhaust gas flows under pressure and forms a small amount of internal leakage at the valve disc, which is directly discharged through the heat storage body and furnace without incineration. At the same time, the valve stem causes wear on the sealing packing during the reciprocating movement, causing exhaust gas to directly leak into the atmosphere through the packing, resulting in external leakage. In addition, there is also high-temperature flue gas inside the RTO dedicated valve. After long-term operation, the original valve stem and valve disc have varying degrees of corrosion damage. Due to the aforementioned issues in the original directional valve design, even a small amount of leakage can have a significant impact on the emission indicators under strict emission and environmental indicators. Therefore, it is necessary to improve the sealing and resistance of the valve through modification. Enable the equipment to meet the requirements of long-term stable operation under existing operating conditions.

Structural issues and improvement plans of RTO specialized valves

Based on the leakage and damage situation of the device's directional valve after long-term operation, combined with the location of the fault point, the structure of the RTO dedicated valve can be analyzed from the following three aspects and improvement methods can be considered:

①The main moving components of the directional valve stem material and its connecting structure are the stem and circular valve disc.Due to frequent movement of the valve, the sealing structure and support structure bear heavy loads。In addition, the exhaust gas inside the furnace has a high temperature and is corrosive.After the equipment has been running for a period of time, the valve stem and valve disc have shown some degree of wear and damage. After on-site measurement and inspection, it was found that there was some wear and damage.The parallelism deviation between the valve disc and the sealing surface. Therefore, measures should be taken to reduce the weight of the valve plate and stem, replace materials, and add a misalignment compensation mechanism, so that RTO specialized valves have a longer service life and better sealing effect.

②In the original valve disc sealing structure design of RTO specialized valves, the circular valve disc can only be sealed when it deforms itself when in contact with the sealing surface. Due to the inability to ensure machining accuracy and the wear of the support structure caused by long-term operation, the circular valve disc and sealing surface cannot be in close contact at all positions on the circumference.Therefore, it is necessary to redesign the valve disc sealing structure to ensure the reliability of the RTO specialized valve sealing during long-term operation.

③In the original design of the valve stem sealing structure and support structure for RTO specialized valves, the valve stem seal adopts a packing type seal.Due to the high operating frequency of RTO specialized valves, the loss of sealing packing here is very fast.The support structure of the valve stem is a support bearing composed of three rubber wheels symmetrically arranged on both sides.After removing the support bearing, it was found that the surface of the pulley was deformed due to long-term use; The pulley shaft is severely worn due to long-term dry wear with the shaft sleeve; Some pulleys cannot rotate properly.In addition, upon inspection, it was found that although the RTO specialized valve support bearing has a certain centering function, it is difficult to ensure the concentricity between the valve stem and the sealing box when using this structure at both ends of the valve stem, which will exacerbate the wear of the packing. After the packing is worn out, exhaust gas leaks from here. Therefore, it is necessary to redesign the sealing structure and support mechanism of the RTO specialized valve stem to achieve better stem sealing effect and longer service life for RTO specialized valves.

■ Application scope

►  Water configuration pipeline

►  Industrial Cleaning Machines

►  Disinfection, boiler

►  Air conditioning equipment, water filters

►  Medical equipment, vacuum pads

►  Food and Beverage Production Line

►  Vacuum configuration pipeline