Water Tube Boilers or Fire Tube Boilers: Which is Safest?

When choosing a new steam boiler, it often comes down to a choice between the traditional fire tube boilers and the newer water tube boilers. There are differences between each type that could make one a better fit than the other, depending on your need. However, boiler safety should always be a top priority with steam boilers, and in that respect, water tube boilers are the better option.

The feature that makes water tube boilers so much safer is the volume of water in them. In a water tube boiler, specifically, ones designed by Miura, the boiler contains a minimal amount of water at any given time. It may be just one-tenth the volume of a fire tube boiler, which requires a larger volume of water to act as a heat shield so that metal in the boiler doesn’t melt and create problems.

When fire tube boilers run low on water, the metal in the boilers shrinks. In such an instance, if cold water is sent into the boiler, the metal could quickly expand, causing an explosion. However, with less water present in a water tube boiler, if anything goes wrong, the explosion won’t be anywhere near as serious as it would be in a fire tube boiler.

“Because Miura only has a tenth of the water volume and all the water is within the tubes,” explains Brandon Hargett of Boiler Masters Inc., “if a tube ruptures it’s only a localized failure to that tube. It’s not a catastrophic explosion of the vessel where all that energy must be relieved at one time.”

Miura’s water tube boilers also make it more difficult to bypass safeties and controls that have to be cleared for the boiler to come online and run. It’s possible to skip these steps with a conventional fire tube boiler — making them more susceptible to explosions. But Miura’s design prevents this from happening.

Going all the way back to when Miura started producing boilers in 1959, there are no documented cases of explosions resulting in casualties, making it clear that Miura’s once-through water tube boilers are the safer choice compared to fire tube boilers. Contact us today to learn more about Miura’s safe compact boilers.