GJ6-2Y 、YGJ10-3 and YGJ30-5 type hign-pressure grouting lining-making machine(Furnace Defender?) are special machines used for grouting and lining-making of equipments such as blast furnaces, hot-blast stoves and hot blast pipelines etc. They are the third and fourth generations of high-tech products shifted from military to civilian purpose subsequent to similar series of grouting machines, all the raw materials used for their main components and parts are military products and so they possess unique technical properties.