OT Question on steam

[Rusty]

I see all the projects going on and I know there is a fellow near me that advertises small steam engines from 1/2- 5 H.P. I was thinking something like that would be really cool but then the thoughts of the boiler and firebox came to mind. I've never seen any small set ups with that detail pictured. All the attention always seems to be on the engine it's self. Do the same people that sell the engines sell the rest of the works? I'm thinking there just might be more danger to live steam than a novice would first think.

[Pitchy]

Usually they do sell boilers too and yep ya either love steam or hate it, kinda like black powder.

[Cliff]

Steam boilers can be dangerous if not properly set up with safety valves and such. I remember something about some here in Florida wanted to build a small steam powered skiff or boat. Found he needed to be a certified steam engineer license. I have seen pictures of a railroad roundhouse, flattened from a Donkey Engine which was steam powered, the engineer left it unattended to eat lunch. Little engine used to move cars and locomotives at the round house. They found some body parts hanging on telegraph wires a quarter of a mile away from the explosion. Steam can be dangerous at high pressures. I don't know if you can find more information on something like Google or not. My grandfather was a steam engine engineer at the turn of the 19 to 20th century. You have to respect steams power. FWIW.

[Ben_Rumson]

Oh steam is a snap...Watching any TV or Western Movie will tell you that... We all know any hero or bad guy can just jump in the cab and run one... Just pull back on the throttle...Always cracks me up ....

[Mainehunter]

You just need to know what you can or can't do. Yes steam is dangerous but if kept in check it's fine. I deal with it day in and day out in the medical field I work on steam sterilizers in the hospitals. Sorta of like an over sized pressure cooker to sterilize OR instruments.

Mainehunter

[Cimarron]

You are correct to ask about steam boilers. The modern steam boiler us usually an automatic type. That is to say the controls for water and fire are automatic. If the water gets low a pump will add it. If more steam is needed the fuel to the burners will be increased or vice versa. If you are talking about a manual boiler then it is the responsibility of the operator to know all about it. There are safety devices. Safety valve (sometimes called the pop valve releaves steam pressure at a predetermined point), gauge glass (it lets you know the level of the water inside the boiler), steam gauge (it tells you the pressure of the steam inside the boiler), try cocks (if the gauge glass breaks you can still assertain the water level) and the fuseable plug in locomotive style boilers (if the water falls below the top of the firebox the tin plug of metal will melt out and put the fire out as well as get your attention). Some state or local governments require an operators licenes or state inspection of boilers and pressure vessels. Check with your state Dept. of Labor or other similar agency. Our steam group started an operators school 25 years ago to help the novice understand steam engine operation.

[jeepnik]

Boilers can be broken down into two classes. Low pressure boilers, anything under 15 psig. High pressure is of course anything over 15 psig. Generally, you don't need any sort of license to operate a low pressure boiler, and many operate unattended. High pressure boilers can run up into several thousands psig of operating pressure for a "critical" boiler. But, generally most industrial boilers can be divided into "saturated" steam boilers and "superheated" steam boilers. Most commonly in industry, boilers are of the "saturated" steam variety, with two types being most common. Those are Watertube or Firetube. The difference is whether the water, or the fire is "inside" the boiler tubes. Obviously that's grossly over simplified, but it's good for a general explaination.

Even a small "high pressure" boiler can create a considerable amount of damage if not run or maintained properly. Pretty much every boiler today, unless it's very, very old, has safety shutdowns that operate on high pressure, low and or high water level, high flue gas temperature, and flame failure. These along with the pressure relief valves make boilers pretty safe to operate. That is right up to the time some really smart (at least they think so) indivdual starts gaging relief valves, or bypassing shutdowns.

And remember, you can't just pump some tap water into a boiler and make steam for very long. Without proper pretreatment of the water, scale will rapidly build up on the heat transfer surfaces, this will result in overheating of those surfaces, and eventual failure. Sometime catastrophic failure, as in a very loud noise and parts moving away at a rapid pace.

Other more insidious damage to the boile can occur if the oxygen isn't removed before you try and make steam. When you boil water in a pan, little bubbles or "air", acutally usually oxygen, form on the pan bottom and sides until they get so large they burst free of the pan. The same thing happens in a boiler that has oxygen in the water. But it's happening at much high temperatures, and results in little pits being formed in the steel. Eventually, it makes a hole in the steel. Now this isn't much of a concern for a very small "hobby" boiler that's operated at say 5 or 10 psig, but it's something to think about if you run it for long periods of time.

I guess my point with this rambling on is that "live" steam is very useful, and also very dangerous is not handled properly. Or as an old mentor in the Oil industry taught me, "Just keep it in the pipes".