If the valve has been casting, found that the sealing surface of sand or sand embedded, the first thing to do is to assess the severity of the problem. For minor sand entrapment (such as a single small sand eye, sand shallow embedded), you can try temporary repair: angle grinder fitted with a diamond grinding head, gently grinding along the edges of the sand eye, like digging out the bad spots on the apple, the embedded sand particles and the surrounding loose metal grinding off, revealing a clean substrate. Next, choose a high-strength metal repair adhesive, mix it proportionally and fill in the sanded pit, scrape it flat with a spatula, wait for the adhesive to harden, and then use fine sandpaper or abrasive paste to sand the repair until it is flush with the sealing surface. However, it should be noted that this method is only applicable to low-pressure pipelines or non-critical parts of the valve, high temperature and high pressure environment can never be used - repair adhesive in the strong pressure or high temperature may fall off, but triggered by greater leakage.
If the sand problem is serious (deep sand holes, a large number, or even embedded in pieces), do not hold the 'make do and fix' mentality. Their own torch repair is the most dangerous practice: welding high temperature will lead to local overheating and deformation of the sealing surface, the original flat sealing surface may become 'wavy', not to mention the repair of sand holes, after the repair may leak even more. The correct approach is to contact the manufacturer directly to return to the factory to deal with, or replace the new valve - although troublesome, but compared to the subsequent leakage caused by the loss of downtime, this is a more economical choice.
Don't take lightly the dangers of cast iron foot valve,globe valve casting,butterfly valve casting sand entrapment, which can seriously affect huge economic losses.