Treatment method of leakage of high and medium pressure butterfly valve
Addtime：2023-04-23 From： View：1029
High school pressure butterfly valve leakage is a more common problem, but in some important systems and equipment, high school pressure butterfly valve once leakage will affect industrial production and serious some will endanger the safety of people's lives and property. The high pressure butterfly valve is connected with the main and auxiliary equipment and system of the power station, and its importance is self-evident. The following analysis of several high pressure butterfly valve leakage treatment methods:
First, high pressure butterfly valve packing leakage
The stem and packing will form a state of motion between each other, which will be reflected in the use of high pressure butterfly valves. High pressure butterfly valve switch more times, the more movement will be. Coupled with the role of temperature, pressure, etc., will greatly increase the possibility of high pressure butterfly valve packing leakage, in this period of time, the pressure of the packing will gradually reduce, thus aging, elasticity no longer exists. The pressure medium will leak outwardly from the contact gap between the packing and the valve stem. If this problem is not properly solved, with the passage of time, the seasoning is blown away and the valve stem is removed from the groove, so that the leakage surface is bigger and bigger.
Two, flange leakage
Flange leakage is often caused by more than one reason, such as the sealing gasket compression force is not enough, the roughness of the combined surface is a certain distance away from the requirements, the gasket deformation, resulting in the sealing gasket and flange did not reach full contact and the gap, the leakage is also produced. At the same time, the reasons for the flange surface seal is not strict are bolt deformation or elongation, gasket aging, return force reduction, cracking, etc., which can also produce leakage. In addition, human factors are also flange leakage needs special attention. In addition, the valve body will also produce the problem of leakage due to the limitation of space, here do not repeat.
Three, the treatment of high pressure butterfly valve external leakage method
Packing chamber leakage with pressure plugging treatment
There are many ways to deal with the external leakage of high pressure butterfly valve in power station, among which the more secure is the injection type with pressure plugging technology, which has been more detailed conclusions. This method uses a special fixture and a hydraulic injection tool. The sealant is injected into the sealing cavity formed by the fixture and part of the outer surface of the leakage site. The effect of repairing the leakage defect is better, and the time is shorter. When the pressure of the injection exceeds the pressure of the leaking medium, it will be strong to stop the leakage, so that the injection is transformed from a plastic body to an elastic body. At this time, the sealing structure has a certain elasticity, and there is a certain specific pressure of the working seal. The secondary sealing is formed eventually, which undoubtedly increases the good sealing. Nowadays, the sealant injection used and widely used in our country is the following two kinds of: (1) thermocure sealant. The use of this injection needs to meet certain conditions, that is, temperature, temperature reaches a certain degree, the injection is an elastic body, in general, solid. (2) non-heat curing sealing agent. It has a wide range of application, can be operated under various temperature conditions, high pressure injection gun can also be installed, injection and filling are good, high pressure butterfly valve switch function can also be well preserved. When the wall thickness of the high school pressure butterfly valve packing box is more than 8 mm, the injection hole can be set directly on the wall of the high school pressure butterfly valve packing box, the sealing cavity is the high school pressure butterfly valve packing box itself, the sealing agent can play the same role as the packing. Find a bit with a diameter of 10.5mm or 8.7mm on the outer wall of the packing box of the high pressure butterfly valve. It is important to emphasize that the hole should not be drilled through. The distance should be between 1-3 mm. Pull the bit out and tap with M12 or MIO. The valve should be in the open state, and then the selection of a long rod bit, should be selected is 3 mm diameter, in order to drill through the remaining high pressure butterfly valve packing wall, leakage will be expelled with the direction of the bit. Drilling will have a certain risk, mainly because the temperature or pressure is too large or contains toxic substances ejecta will bring certain injuries to the staff, light injury, serious will also threaten the safety of life, so this absolutely can not be ignored, drilling before the baffle is a better control method.
Flange leakage with pressure plugging treatment of copper wire containment method
The scope of application of this method is that the two flange clearance is small, the gap is uniform, the leakage medium pressure is low with pressure plugging, the bolt special injection joint shadow is placed on the removed bolt, two are lower, should be greater than two. When installing the injection joint, do not tighten all the nuts, but loosen one. After installing the injection joint, tighten the nuts immediately and install other injection joints. It should be emphasized that the required joint nuts should not be loosened at the same time, because it will reduce the specific sealing pressure on the gasket, increase the leakage amount, and in serious cases, the leakage material will blow away the gasket. If this happens, it is difficult to remedy and the damage is incalculable.
Valve body leakage with pressure plugging treatment
1. Bonding method
If it is the pressure medium and the small amount of leakage of the sand hole, you can first polish the metal luster around the leak point, and then use taper pins to align with the leak point, with appropriate strength to drive in, mainly in order to reduce leakage or temporary plugging. The adhesive curing speed is relatively fast, which can be used to apply the adhesive around the pin, thus forming a new solid seal structure, which can produce a leak-stopping effect to some extent. If the medium pressure is high and the leakage is large, the sealing operation can be carried out by using the way of top pressure tool. During the operation, the top pressure mechanism is fixed on the side of the high school pressure butterfly valve, the high-speed item pressure screw, so that the axial direction of the top pressure screw is opposite to the leakage point, the rotating item pressure screw, and the rivet of the top pressure screw end is tightly pressed on the leakage site, which is also an effective way to stop the leakage. If the top of the rivet is smaller than the area of the leakage point, a soft metal sheet can be padded under the rivet. When the leakage stops, the metal surface around the leakage point should be cleaned in time.
2. Welding method
If the valve body leakage medium pressure is low, leakage is small, available than the inner diameter more than twice the leak point of the nut, so that the leakage medium from the nut out, the nut welded to the valve body, with a bolt of the same specification with the nut, placed at the bottom of the nut a rubber pad or asbestos pad, the top of the bolt around the raw tape screw into the nut, Can effectively reduce the occurrence of leakage. If the valve body leakage medium pressure is high, the leakage amount is large, then the drainage welding method is a better method. First, use a piece of iron plate, open a round hole in the middle, weld an isolation valve of the same caliber as the round hole on the iron plate, open the isolation valve, align the center hole of the iron plate with the leakage point and fit in the valve body, let the leakage medium flow out through the center hole of the iron plate and the isolation valve. For the laminating surface is not good, it can be used to place rubber or asbestos pad on the laminating surface, and then weld the iron plate around the valve body, and then close the isolation valve, so that the sealing effect can be achieved.
First, high pressure butterfly valve packing leakage
The stem and packing will form a state of motion between each other, which will be reflected in the use of high pressure butterfly valves. High pressure butterfly valve switch more times, the more movement will be. Coupled with the role of temperature, pressure, etc., will greatly increase the possibility of high pressure butterfly valve packing leakage, in this period of time, the pressure of the packing will gradually reduce, thus aging, elasticity no longer exists. The pressure medium will leak outwardly from the contact gap between the packing and the valve stem. If this problem is not properly solved, with the passage of time, the seasoning is blown away and the valve stem is removed from the groove, so that the leakage surface is bigger and bigger.
Two, flange leakage
Flange leakage is often caused by more than one reason, such as the sealing gasket compression force is not enough, the roughness of the combined surface is a certain distance away from the requirements, the gasket deformation, resulting in the sealing gasket and flange did not reach full contact and the gap, the leakage is also produced. At the same time, the reasons for the flange surface seal is not strict are bolt deformation or elongation, gasket aging, return force reduction, cracking, etc., which can also produce leakage. In addition, human factors are also flange leakage needs special attention. In addition, the valve body will also produce the problem of leakage due to the limitation of space, here do not repeat.
Three, the treatment of high pressure butterfly valve external leakage method
Packing chamber leakage with pressure plugging treatment
There are many ways to deal with the external leakage of high pressure butterfly valve in power station, among which the more secure is the injection type with pressure plugging technology, which has been more detailed conclusions. This method uses a special fixture and a hydraulic injection tool. The sealant is injected into the sealing cavity formed by the fixture and part of the outer surface of the leakage site. The effect of repairing the leakage defect is better, and the time is shorter. When the pressure of the injection exceeds the pressure of the leaking medium, it will be strong to stop the leakage, so that the injection is transformed from a plastic body to an elastic body. At this time, the sealing structure has a certain elasticity, and there is a certain specific pressure of the working seal. The secondary sealing is formed eventually, which undoubtedly increases the good sealing. Nowadays, the sealant injection used and widely used in our country is the following two kinds of: (1) thermocure sealant. The use of this injection needs to meet certain conditions, that is, temperature, temperature reaches a certain degree, the injection is an elastic body, in general, solid. (2) non-heat curing sealing agent. It has a wide range of application, can be operated under various temperature conditions, high pressure injection gun can also be installed, injection and filling are good, high pressure butterfly valve switch function can also be well preserved. When the wall thickness of the high school pressure butterfly valve packing box is more than 8 mm, the injection hole can be set directly on the wall of the high school pressure butterfly valve packing box, the sealing cavity is the high school pressure butterfly valve packing box itself, the sealing agent can play the same role as the packing. Find a bit with a diameter of 10.5mm or 8.7mm on the outer wall of the packing box of the high pressure butterfly valve. It is important to emphasize that the hole should not be drilled through. The distance should be between 1-3 mm. Pull the bit out and tap with M12 or MIO. The valve should be in the open state, and then the selection of a long rod bit, should be selected is 3 mm diameter, in order to drill through the remaining high pressure butterfly valve packing wall, leakage will be expelled with the direction of the bit. Drilling will have a certain risk, mainly because the temperature or pressure is too large or contains toxic substances ejecta will bring certain injuries to the staff, light injury, serious will also threaten the safety of life, so this absolutely can not be ignored, drilling before the baffle is a better control method.
Flange leakage with pressure plugging treatment of copper wire containment method
The scope of application of this method is that the two flange clearance is small, the gap is uniform, the leakage medium pressure is low with pressure plugging, the bolt special injection joint shadow is placed on the removed bolt, two are lower, should be greater than two. When installing the injection joint, do not tighten all the nuts, but loosen one. After installing the injection joint, tighten the nuts immediately and install other injection joints. It should be emphasized that the required joint nuts should not be loosened at the same time, because it will reduce the specific sealing pressure on the gasket, increase the leakage amount, and in serious cases, the leakage material will blow away the gasket. If this happens, it is difficult to remedy and the damage is incalculable.
Valve body leakage with pressure plugging treatment
1. Bonding method
If it is the pressure medium and the small amount of leakage of the sand hole, you can first polish the metal luster around the leak point, and then use taper pins to align with the leak point, with appropriate strength to drive in, mainly in order to reduce leakage or temporary plugging. The adhesive curing speed is relatively fast, which can be used to apply the adhesive around the pin, thus forming a new solid seal structure, which can produce a leak-stopping effect to some extent. If the medium pressure is high and the leakage is large, the sealing operation can be carried out by using the way of top pressure tool. During the operation, the top pressure mechanism is fixed on the side of the high school pressure butterfly valve, the high-speed item pressure screw, so that the axial direction of the top pressure screw is opposite to the leakage point, the rotating item pressure screw, and the rivet of the top pressure screw end is tightly pressed on the leakage site, which is also an effective way to stop the leakage. If the top of the rivet is smaller than the area of the leakage point, a soft metal sheet can be padded under the rivet. When the leakage stops, the metal surface around the leakage point should be cleaned in time.
2. Welding method
If the valve body leakage medium pressure is low, leakage is small, available than the inner diameter more than twice the leak point of the nut, so that the leakage medium from the nut out, the nut welded to the valve body, with a bolt of the same specification with the nut, placed at the bottom of the nut a rubber pad or asbestos pad, the top of the bolt around the raw tape screw into the nut, Can effectively reduce the occurrence of leakage. If the valve body leakage medium pressure is high, the leakage amount is large, then the drainage welding method is a better method. First, use a piece of iron plate, open a round hole in the middle, weld an isolation valve of the same caliber as the round hole on the iron plate, open the isolation valve, align the center hole of the iron plate with the leakage point and fit in the valve body, let the leakage medium flow out through the center hole of the iron plate and the isolation valve. For the laminating surface is not good, it can be used to place rubber or asbestos pad on the laminating surface, and then weld the iron plate around the valve body, and then close the isolation valve, so that the sealing effect can be achieved.