We have some pinhole leaks in our fire sprinkler system in a large residential apartment block. Can you recommend a sealant that will stop the leaks to give us some time before we have to replace the entire system?
Fire sprinkler systems are very difficult and expensive to replace or repair because the piping is often inside walls and ceilings. Some companies sell two-part epoxy adhesives that are fast curing and designed specifically for repairing this type of leak. In fact, you can buy kits that comprise an epoxy putty stick plus an impregnated fiberglass tape.
Another product is a low-viscosity anaerobic methacrylate liquid that will seal many pinhole leaks. In order to use this, you have to empty the pipe of water and dry it thoroughly. Heat the pipe using a flame or hot air gun and then apply the anaerobic. As the pipe cools down, the liquid will penetrate into the porosity and then cure. These types of repairs do not have any sort of code approval, however, and you need to access the specific leaks.