Leak plugging of non-metallic expansion joint in thermal power plant

Non-metallic expansion joints in thermal power plants are mainly used to absorb displacements of piping systems due to thermal expansion and contraction, vibration or installation errors, especially in high temperature, high pressure and corrosive environments. When the non-metallic expansion joint leaks, appropriate plugging measures should be taken to ensure the safety and efficiency of the system. The following are the general steps and technical points for plugging non-metallic expansion joints in thermal power plants:

Preparation before plugging a leak

1. Downtime Preparation: First, make sure that the system where the leak is located has stopped running, cooled to a safe temperature, and the pressure is released.

2. Safety measures: Wear personal protective equipment, ensure that the working area is well ventilated and there is no fire source, and set up warning signs to isolate the leakage area.

3. Tool and Material Preparation: Prepare high elastic glue, high temperature and corrosion resistant high elastic sponge polyurethane filler, acid-resistant water-blocking adhesive, special sealing materials, pressure plates, screws, etc.

Cleanup & Patching

1. Clean the platen: Carefully clean up the accumulated dust on the platen to avoid damaging the PTFE skin at the bottom of the groove.

2. Clean skeleton: Thoroughly clean the floating dust on the non-metallic expansion joint skeleton to ensure a clean surface.

Plugging Implementation

1. Apply high elasticity glue: Quickly apply the high elastic glue to the expansion joint compression plate and both sides before curing.

2. Filling with corrosion-resistant fillersWhen the high elasticity glue is not cured, the high temperature and corrosion resistant high elasticity sponge polyurethane filler is quickly filled into the groove.

3. Multilayer plugging: Every time the filler is filled, seal a layer of glue until the gap of the pressing plate is completely filled. The top layer should be particularly careful, flattened with high elasticity, acid and glue resistance, and the thickness should be controlled at about 3mm.

4. Seam treatment: Finally, apply high-elasticity corrosion-resistant glue to all joints, and keep the thickness above 3mm to ensure complete seal.

Acceptance and Testing

1. Appearance inspection: Check whether the plugged area is flat and there are no obvious cracks or bumps.

2. Stress testing: Under the premise of ensuring safety, carry out pressure test on the repaired expansion joint to check whether there is still leakage.

3. Temperature test: After system operation, the tightness of the expansion joint under high temperature conditions is monitored.

Long-term maintenance

1. Periodic inspection: Establish a regular inspection system to observe the sealing condition and performance of the expansion joint.

2. Record Maintenance: Record the results of each maintenance and inspection in order to track the health of the expansion joint.

When performing plugging operations, it is important to follow all safety protocols, ensure that the correct materials and techniques are used, and follow the manufacturer's guidance recommendations. In complex or high-risk situations, a professional repair team may be required to operate.