Precautions for valve stem scratch repair

Precautions for valve stem scratch repair

How to repair a scratched valve stem?

① Use a file to remove the burrs on the scratched area of the valve stem. For shallow scratches, use a flat chisel to process the area to a depth of about 1mm, then roughen the surface with sandpaper or an angle grinder. At this point, the new metal surface will be exposed.

② Clean the surface with TL-700 metal cleaner to ensure the repaired area is free of oil, dust, and other contaminants.

③ Apply a wear-resistant repair agent.

④ Perform detailed finishing.

Preparation and Application Process of Wear-Resistant Repair Agent:

① Prepare the repair agent by mixing in a volume ratio of 3.8:1.

② Apply the adhesive to the scratched surface, starting with a thin first coat. Apply from top to bottom, ensuring no air bubbles are present.

③ After the first coat of adhesive has cured for 1 hour (i.e., the adhesive has partially solidified), re-mix the repair agent as required and apply the second coat. The second coat should exceed the original dimensions by 1-2mm.

④ After allowing the repair to naturally cure for 1 hour, heat it with an iodine-tungsten lamp at 80-100°C for 3 hours.

Detailed finishing process requirements：

① Use tools such as a file, scraper, and sandpaper to remove the adhesive that exceeds the original dimensions. During the process, measure frequently to ensure the adhesive layer does not fall below the original size, and leave 0.5mm as allowance for fine finishing.

② Once the dimensions reach the fine finishing allowance, use a pre-machined grinding tool for finishing, placing 80-grit sandpaper underneath for smoothing.

③ When the dimensions exceed the original size by 0.2mm, replace the abrasive with diamond grit and grind until the actual dimensional accuracy is achieved.

Precautions:

Since on-site repair is being used, it is essential to clean the surrounding area (especially the upper part) of dust, oil, and other contaminants to ensure repair quality. If any defects (such as small air pockets) occur after the repair, apply additional adhesive, following the same procedure as before.

The above pertains to the repair methods for valve-stem-equipped valves and does not include titanium check valves.