Pressure drop for two phase flow of air-water and water-oil system for a sudden expansion and contraction in a pipe has been computed numerically by solving the two phase flow equations in an Eulerian-Eulerian system. The effect of volume concentration of oil and air on pressured drop has been predicted for different geometrical parameters. Pressure drop in thin and thick orifices has been computed with the prediction of a two-phase multiplier, such that when the multiplier is multiplied to the pressure drop for a single phase flow then the pressured drop for two phase flow can be predicted.