blog on Webster steam systems

Dave Meers

I'm in the middle of a streak of experiences with the Webster system of steam heating, circa the early 1900's. I thought I would share a few thoughts, like a blog. Feel free to share some of your thoughts and debate the merits of this system.

I did some more research on Webster previous to two seminars I taught last week. I found a mansion built in 1926 that is available for meetings. A wonderful steam system is still working proud, although some modifications have been made. I set it up as a hands on event, a little lecture in the ball room and then off to the basement to walk around looking at the pipes, talking steam theory and times gone past. I had a great time.

There is a recent thread on the wall here from vic ny about a Webster system he is having some problems with that I tried to give some input to. Then today Roger Litman of North Shore Fuels asked me about a Webster system. Things run in streaks in this biz.

I have always admired a good steam system and the Webster was a true system. Their literature boasted the fact that you didn't buy just components, you had to buy the whole system, engineered by their representatives. They would supervise the installation and make sure it worked upon completion. Their theory was controlled steam distribution (steam up). They would use metering type supply valves or orifices on the radiation to balance the steam flow. It was a two pipe system with steam traps on the radiators to pass the air and condensate to the dry return but keep the steam out of the dry return. Back in the boiler room, a matched set of boiler return trap and vent trap, sized for the system load of both air and condensate, would work together to allow the air to pass out of the system (air out) and return the condensate to the boiler (water back).

Here is where you have to remember that the boiler was coal-fired. That means somebody shoveled the coal in and adjusted the draft doors to get a good fire going to make steam. A draft regulator would act to try to control steam pressure to 2# or so, but it is hard to turn off the heat once you got a good fire going. The coal fire would sometimes get the pressure high enough that the returning condensate could not push its way back into the boiler with its available "b" dimension. So most manufacturers had a return trap in their line. The Webster boiler return trap operates like most of the others. As water builds up in its float chamber because of the rising steam pressure in the boiler, the float opens a valve to allow steam to enter the top of the float chamber. This steam pressure, equal to the pressure in the boiler, plus the gravity pressure of the stacking effect of the water in the chamber is now greater than the pressure in the boiler, so water flows back into the boiler. Two check valves in the wet return below the boiler return trap make sure the water goes into the boiler and not back into the return line. The float trap could hold a whole cycle's worth of water, they are huge. If the water rose up in the float trap, a valve would close to prevent water from escaping through the vent valve. The vent valve was an open port with a ball and a cap. Slight pressure, as low as 3 ounces, would lift the ball off the seat to allow air to pass from the mains. The ball would fall back in place to prevent air from returning to the system so a vacuum could be formed. This was a feature for a coal fired system, not used with today's automatic fired burners. Most systems would operate today with the ball removed. This was actually recommended by Webster back then if the radiation for the system was blast coils. They were concerned with low temperature steam (under vacuum steam temperatures drop) in fan-powered radiation.

I have run out of time for posting, off to a union hall to talk to the students about steam. I will try to blog some more on this subject in the future.

Best regards, Pat