The water inlet speed before the start of the gas hot water boiler should not be too fast, generally not less than 4h in winter, and 2~3h in other seasons, especially in the initial stage of water intake. The inlet temperature of the gas hot water boiler is generally 50-90 ° C, so that the difference between the feed water temperature entering the steam drum and the steam wall temperature is not more than 40 ° C. For gas-fired hot water boilers that are not completely cooled, the inlet water temperature may be comparable to the temperature of the steam drum wall, otherwise the water inlet speed should be slowed down.
When the feed water enters the steam drum, it always touches the lower half of the steam drum first. If the difference between the feed water temperature and the steam drum wall temperature is too large, the water inlet speed is fast, and the upper and lower walls of the steam drum, the inner and outer walls will have a large expansion. Poor, causing a large additional stress on the steam drum, causing deformation of the steam drum and cracking in severe cases.
Since the wall of the steam drum is thick, the expansion is slow, and the wall of the pipe connected to the wall of the steam drum is thinner and expands faster. If the inlet temperature of the gas hot water boiler is too high or the water inlet speed is too fast, it will cause uneven expansion, causing cracks in the weld joint and causing damage to the gas hot water boiler.
