SUMMARY
The KB-5 high pressure gas burners were popularly and widely used in Thailand. This research was aimed to study the influence of four significant parameters, namely degrees of outer and inner ports and the number of outer and inner ports of high pressure gas burners, to the thermal efficiency by the experiments. The thermal efficiency was tested with reference to the standard industrial stoves in household with liquid petroleum gas (TIS 2312-2549). The results were shown the increasing angles of the outer port increased 13% thermal efficiency, the increasing numbers of outer port increased 5% thermal efficiency and increasing the numbers of inner port increased 7% thermal efficiency from the factory's model. The increasing angles of inner port had less effect on thermal efficiency. The improving of high pressure gas burner will have modified by increased the numbers of outer and inner port and the angles of the outer port for the higher thermal efficiency than the factory's design.