Maintenance of Ball Valve during grease injection

When greasing a Ball Valve, the amount of grease injection is often ignored. After the grease gun is refueled, the operator selects the Ball Valve and the grease injection connection method, and then performs the grease injection operation. There are two situations: on the one hand, the small amount of grease injection leads to insufficient grease injection, and the sealing surface wears faster due to lack of lubricant. On the other hand, excessive grease injection causes waste. It is because the sealing capacity of different Ball Valve is not accurately calculated according to the type of Ball Valve. The sealing capacity can be calculated according to the size and type of the Ball Valve, and then the appropriate amount of grease can be reasonably injected. When greasing a Ball Valve, the pressure problem is often ignored. During the greasing operation, the grease injection pressure changes regularly in peaks and valleys. If the pressure is too low, the seal leaks or fails, and if the pressure is too high, the grease injection port is blocked, and the grease inside the seal or the seal ring is locked with the valve ball and valve plate. Usually, when the grease injection pressure is too low, the injected grease flows into the bottom of the valve cavity, which usually occurs in small gate valves. If the grease injection pressure is too high, on the one hand, check the grease injection nozzle. If the grease hole is blocked, replace it according to the situation. On the other hand, if the grease is hardened, use cleaning fluid to repeatedly soften the failed sealing grease and inject new grease to replace it. In addition, the seal model and seal material also affect the grease injection pressure. Different seal forms have different grease injection pressures. Generally, the grease injection pressure of hard seals is higher than that of soft seals. When greasing the Ball Valve, pay attention to the switch position of the Ball Valve. The Ball Valve is generally in the open position during maintenance, and closed maintenance is selected in special circumstances. Other Ball Valve cannot be treated as open positions. Gate valves must be in the closed position during maintenance to ensure that the grease fills the sealing groove along the sealing ring. If it is in the open position, the sealing grease directly enters the flow channel or valve cavity, causing waste. When greasing the Ball Valve, the grease injection effect is often ignored. The pressure, grease injection amount, and switch position are normal during the grease injection operation. However, in order to ensure the grease injection effect of the Ball Valve, it is sometimes necessary to open or close the Ball Valve to check the lubrication effect and confirm that the surface of the Ball Valve or gate is evenly lubricated. When injecting grease, pay attention to the problem of draining the valve body and the pressure relief of the plug. After the Ball Valve is pressure tested, the gas and moisture in the sealing chamber will increase due to the increase in ambient temperature. When injecting grease, drain and relieve the pressure first to facilitate the smooth progress of the grease injection. After grease injection, the air and moisture in the sealing chamber are fully replaced. Timely release of the valve chamber pressure also ensures the safety of the Ball Valve. After the grease injection, be sure to tighten the drain and pressure relief plugs to prevent accidents. When injecting grease, you should also observe the flushing of the Ball Valve diameter and the sealing ring seat. For example, if there is an open position interference with the Ball Valve, you can adjust the open position limiter inward and confirm that the diameter is straight before setting. When adjusting the limit, you cannot only pursue the open or closed position, but consider the overall situation. If the open position is flush and the closing position is not in place, the Ball Valve will not be closed tightly. Similarly, when adjusting the closing position, you should also consider the corresponding adjustment of the open position. Ensure the right-angle stroke of the Ball Valve. After grease injection, be sure to seal the grease injection port. Prevent impurities from entering or lipid oxidation at the grease injection port, and apply anti-rust grease to the cap to prevent rust. For the next operation and application.

17 October-2024

Maintenance of Ball Valve packing

The packing is directly related to whether the Ball Valve leaks when it is switched. If the packing fails and causes leakage, the Ball Valve will also fail, especially the Ball Valve of the urea pipeline, because its temperature is relatively high, the corrosion is relatively serious, and the packing is easy to age. Strengthening maintenance can extend the life of the packing. When the Ball Valve leaves the factory, due to factors such as temperature, it may leak out. At this time, the nuts on both sides of the packing gland should be tightened in time. As long as there is no leakage, tighten it again in the future. Do not tighten it all at once to avoid the packing losing elasticity and sealing performance. Some Ball Valve packings are filled with molybdenum dioxide lubricating paste. After several months of use, the corresponding lubricating grease should be added in time. When it is found that the packing needs to be supplemented, the corresponding packing should be added in time to ensure the sealing performance. During the switching process of the Ball Valve, the original lubricating grease will continue to be lost, and coupled with the influence of temperature, corrosion, etc., the lubricating oil will continue to dry up. Therefore, the transmission parts of the Ball Valve should be checked regularly, and if any lubricant is found, it should be replenished in time to prevent increased wear due to lack of lubricant, resulting in malfunctions such as inflexible transmission or jamming.

16 October-2024

Use and maintenance of Ball Valve

The purpose of use and maintenance is to extend the life of the Ball Valve and ensure reliable opening and closing. The valve stem thread often rubs against the valve stem nut, and needs to be coated with yellow dry oil, molybdenum disulfide or graphite powder for lubrication. For Ball Valve that are not frequently opened and closed, the handwheel should also be turned regularly to add lubricant to the valve stem thread to prevent biting. For outdoor Ball Valve, a protective cover should be added to the valve stem to prevent rain, snow, dust and rust. If the Ball Valve is mechanically ready, the gearbox should be lubricated on time. The integrity of the Ball Valve components should always be maintained. If the fixing nut of the handwheel falls off, it should be matched and cannot be used as a makeshift, otherwise the square of the upper part of the valve stem will be rounded, and the matching reliability will gradually be lost, and it may even be unable to start. The valve stem, especially the threaded part, should be wiped frequently, and the lubricant that has been contaminated by dust should be replaced with a new one, because the dust contains shadow impurities, which can easily wear the thread and the surface of the valve stem, affecting the service life of the Ball Valve. The Ball Valve in operation should be maintained once every quarter, once every six months after commissioning, once a year after two years of commissioning, and before winter every year. The Ball Valve flexibility operation and sewage discharge should be performed once a month.

15 October-2024

Storage and maintenance of Throttle Valve

The purpose of storage and maintenance is to prevent the Throttle Valve from being damaged or reducing its quality during storage. In fact, improper storage is one of the important reasons for the damage of Throttle Valve. The storage of Throttle Valve should be well organized. Small Throttle Valve should be placed on the shelves, and large Throttle Valve can be neatly placed on the floor of the warehouse. They should not be piled up randomly, and the flange connection surface should not be directly in contact with the ground. This is not only for aesthetics, but more importantly, to protect the Throttle Valve from being damaged. Due to improper storage or handling, the hand wheel is broken, the valve stem is crooked, and the fixing nut of the hand wheel and the valve stem is loosened and lost. These unnecessary losses should be avoided. For Throttle Valve that are not used in the short term, the asbestos packing should be removed to avoid electrochemical corrosion and damage to the valve stem. The inlet and outlet of the Throttle Valve should be sealed with wax paper or plastic sheets to prevent dirt from entering and affecting the Throttle Valve. For Throttle Valve that can rust in the atmosphere, anti-rust oil should be applied to protect them and prevent rust. Throttle Valve placed outdoors must be covered with rainproof and dustproof items such as tarpaulin or tarpaulin. The warehouse where the Throttle Valve are stored must be kept clean and dry.

14 October-2024

Precautions for selecting and replacing Throttle Valve

The selection of Universal Valve structure is determined by comprehensive consideration of factors such as the medium used, temperature, pressure before and after the valve, flow rate, physical and chemical properties of the medium, and the cleanliness of the medium. The correctness and rationality of the Throttle Valve structure selection are directly related to the performance, adjustment performance, adjustment stability, and service life. 1. Process parameters ① Medium name. ② Medium density, viscosity, temperature, medium cleanliness (with particles). ③ Medium physical and chemical properties: such as corrosiveness, toxicity, acidity and alkalinity. ④ Medium flow: maximum, normal, minimum. ⑤ Medium pressure before and after the valve: maximum, normal, minimum. ⑥ Medium viscosity, the greater the viscosity, the more it affects the calculation of Cv value. These parameters are mainly used to calculate the required caliber, rated Cv value and other dimensional parameters of the Throttle Valve, as well as the appropriate materials that the Throttle Valve should adopt. 2. Functional parameters ① Action mode: electric, pneumatic, electro-hydraulic, hydraulic. ② Throttle Valve function: adjustment, cut-off, adjustment and cut-off common. ③Control mode: positioner, solenoid valve, pressure reducing valve. ④Action time requirements. These parameters are mainly used to determine some accessories required to meet the functional requirements of the Throttle Valve. 3. Explosion-proof protection parameters ① Explosion-proof level. ② Protection level. 4. Environmental and power parameters ① Ambient temperature. ② Power parameters: air source pressure, power supply pressure. If the Throttle Valve is replaced, the following size parameters should also be provided to avoid the Throttle Valve being unable to be installed, or not being installed, or insufficient space due to inconsistency of Throttle Valve manufacturers, different standards adopted, or different Throttle Valve structures.

12 October-2024