Nozzle Filling Chromite Compound (NFC) is a type of sealing material used to fill gaps and spaces between nozzles and the header plate of a heat exchanger. NFC is made from a mixture of chromite, epoxy resin, and other fillers that provide a high level of heat resistance and durability. The chromite in the compound provides an additional layer of protection against high temperatures and harsh environments, making NFC ideal for use in applications such as oil refineries, chemical plants, and power generation facilities. The compound is typically applied to the nozzle area and allowed to cure, creating a tight seal that prevents leaks and improves the efficiency of the heat exchanger. It is important to follow the manufacturer's instructions carefully when applying NFC, as improper application can result in a weak seal or other issues.