Low pressure casting is a casting method in which liquid alloy is pressed from bottom to top into the mold cavity and solidified under pressure. The production process of low pressure casting includes the following four basic processes: 1) Aluminum ingot smelting and preparation of moulds. 2) Preparation before pouring: including crucible seal (assembly of sealing cover), slag scraping in the rising pipe, measurement of liquid level
height, sealing test, mold matching, fastening mold or casting mold, etc. 3) Pouring: including liquid lifting, mold filling, pressure boosting, solidification, pressure relief and cooling, etc. 4) Demoulding: including loose mold demoulding and casting removal.