Can you figure out how to perform pressure sealing just by looking at it? Experts reveal the life-and-death details behind the operation. On the outside of the pipeline, the clamps are tightly securing the leak point. A worker is concentrating fully on operating the high-pressure injection gun, slowly injecting the sealant - this seemingly simple action actually represents a huge responsibility for the safety and environmental protection of equipment worth tens of millions of dollars. In industries such as petroleum, chemical engineering, and gas supply, pipelines continuously transport various substances like blood vessels do. c A win-win situation of both economic and environmental benefits far exceeding expectations Pressure sealing is a technical term referring to the process of stopping the leakage of fluids by cutting off, blocking or isolating the leakage channels while the internal medium of a pipeline or container remains under pressure. The most significant advantage of this technology is the ability to perform maintenance without shutting down production. Traditional pipeline maintenance requires shutting off the flow and emptying the pipeline, which not only incurs huge production losses but also necessitates dealing with the residual medium inside the pipeline, causing environmental pressure. Take a large-scale refining and chemical enterprise as an example. In 2023, through the pressure-sealing leak-fixing technology, they successfully dealt with a flange leakage in a key device, avoiding the complete shutdown of the entire line and directly recovering economic losses of several hundred million yuan. In the field of long-distance pipelines, the professional construction team applied the composite sealing technology, reducing the traditional 7-day maintenance operation to be completed within 24 hours, increasing the construction efficiency by more than 70%. More importantly, the pressure-sealing technology plays an irreplaceable role in environmental protection. According to incomplete statistics, a single medium-sized pressure-sealing operation can prevent the emission of tens to hundreds of cubic meters of media. For toxic, harmful, flammable, and explosive media, its environmental protection value and safety improvement are even more significant. Technical principle: The seemingly simple yet highly sophisticated art of sealing The basic principle of pressure sealing is to use the sealing element to completely block the leakage channel of the medium, or to increase the flow resistance of the fluid in the leakage channel, forming a closed space to achieve the purpose of preventing the fluid from leaking out. The most commonly used clamping injection sealing process is to install custom clamps and inject sealant to form a new sealing layer. To an outsider, this process may seem quite simple - just install a clamp at the leakage point and inject the sealant. However, in actual operation, every detail is crucial to the outcome. The clamp must form an appropriate connection gap with the outer surface of the leakage area, and the sealant must be carefully selected based on the properties of the medium, temperature and pressure. Take the common high-temperature oil and gas medium as an example, the sealant must have corresponding temperature resistance, anti-swelling properties and sufficient fluidity. During the injection operation, start from the injection valve far away from the leakage point and gradually move towards the leakage point until the leakage is completely eliminated. The entire process requires precise control of pressure, temperature, and the injection volume of the sealant. Experienced technicians can even determine the flow state and filling degree of the sealant in the cavity through subtle changes in the injection pressure. Application scope: Extensively covers various industrial scenarios The application scope of pressure-sealing technology is extremely broad. In terms of industrial applications, it covers multiple process industries such as petroleum, chemical engineering, power, metallurgy, and pharmaceuticals, and can handle various conditions ranging from vacuum to 30 MPa pressure and from -50℃ to 900℃ temperature. In terms of the medium type, this technology can effectively seal various chemical substances such as oil, gas, steam, acids, and bases. It is worth noting that for different types of media, completely different sealing schemes are required. Especially for highly toxic and dangerous media, special protective measures and construction techniques must be adopted. In recent years, with the advancement of materials science, the pressure sealing technology has been continuously expanding its application boundaries. For instance, the enhanced clamps developed for ultra-high pressure conditions can withstand higher injection pressures; the special sealants developed for specific media have broadened the technical application scope. However, the pressure sealing technology is prohibited for use in corrosive pipelines with highly toxic media, cracked pressure components, and unknown wall thicknesses. Operation procedure: Precise and meticulous nine-step operation method Under-pressure plugging operations are far from being "easy to do" at a glance. They require strict adherence to professional procedures: On-site investigation and plan formulation - Professional personnel need to have a thorough understanding of the parameters of the leaked medium, temperature and pressure conditions, as well as the surrounding environment, in order to formulate a targeted construction plan. Preparation of tooling fixtures - Based on the shape and size of the leakage area, prepare or customize special fixtures such as clamps and injection valves. Surface treatment and fixture installation - Clean the surface of the leakage area to ensure the sealing performance of the fixture installation. This process requires precise clearance between components. Sealant selection and filling - Based on the properties of the medium and the operating temperature, select the appropriate sealant model and fill it into the injection gun in sequence. Step-by-step glue application operation - Start from the glue injection hole away from the leakage point, and proceed towards the leakage point in sequence. Control the glue injection pressure and speed. Process monitoring and adjustment - Closely observe the changes in leakage, promptly adjust the injection strategy. This process requires rich experience and judgment. Verification of sealing effect - Through methods such as pressure retention tests, the sealing effect is verified to ensure long-term reliability. On-site cleanup and restoration - Clean up the operation site, and restore the equipment to its normal operating condition. Completion report and records - Detailed documentation of the construction process and data, providing a basis for subsequent maintenance. Risk Challenges: Technological Breakthroughs in High-Difficulty Conditions Underpressurized plugging operations encounter various risks and challenges, especially under conditions of high pressure, high temperature, and special media: The risk of the medium is the primary consideration. For flammable and explosive media, any ignition sources must be completely eliminated during the operation; for toxic media, strict protective measures must be taken. When a certain chemical enterprise dealt with the leakage of hydrofluoric acid, it adopted the remote injection gel technology, and the operators were equipped with professional protective equipment, ensuring the safety of the operation.