TSP in the boiler water

[Ofcalipka]

I found this chart for dilution of TSP for helping to prevent corrosion in te boiler and thought if share it here. Does anyone else use this to keep their boilers clean?

http://enginemechanics.tpub.com/14075/css/14075_178.htm

[fredrosse]

There have been many posts on the forum concerning TSP in boiler water, search "Trisodium Phosphate", Tri-Soduim Phosphate, "Phosphate" or try "TSP".

I could not really understand the chart you reference above, but that may just be my poor understanding of chemistry. If you can cypher it, please tell what the chart means.

One thing I noticed is the website recommends draining the boiler if it will not be returned to service within 24 hours. I think full wet layup is the preferred method for all shutdowns throughout the season, and drained/dry layup is only required over winter months to protect from freezing. It takes little effort to put my boiler in cold wet layup, and takes me about 5 hours to put the boiler in drained/dry layup. Drained layup with a wet boiler invites corrosion, and drying it properly takes the time. Drained layup with an inert purge gas would protect against corrosion, but I doubt many of us steamboaters can do that.

Any comments from other forum members?

[Ofcalipka]

The site I found that on is a cache of various government and other manuals. I was only posting the chart as a reference. Basically from left I right. You select the alkalinty epm you are trying to achieve use the number next to it, for instance 1.0 = .05, and multiply that by the number of gallons of water to be treated and the answer should be the number of ounces of TSP to add.

I'm new to this and studying up a bit and was curious as to how much tsp to add with the boiler water to help protect my boiler. What calculations do you all use to determine how much to use after flushing your boiler during regular maintenance?

[fredrosse]

One of the water treatment guys at work started into all kinds of chemistry stuff, depending on the initial water condition, various tests, etc. I told him there is no way I can do all of that, and then he said, "Just add about a Tablespoon of TSP to your 15 gallon raw feedwater tank, that is about right, and add about another half teaspoon to the system now and then"

I buy swimming pool (or fish tank) test strips, they indicate the Ph of the water, and I adjust my TSP additions accordingly, although not too precisely, I manage to keep Ph in the 9 to 11 range. I also bought a Ph meter, but that needs constant calibration, the test strips are simple, and cost only a few dollars for a pack of 25.

[steamdon-jr]

Fred,

I had used TSP on Adelaide for many years and liked the outcome, The little carter mann liked to foam and I found The TSP hepled with that as well, I felt at layup boiler looked well for what you can see with a pen light and a 1/2 inch boiler fitting. I am kind of fussy with boiler maintanance and blow down the glass at minimum once a per steaming to make sure I do not get buildup in the fittings and/or piping to the glass and get a false reading which was the demise of many locos back in the day. I also blow down the boiler once per day at 60-80 PSI after the glass has been filled almost full and then I let the boiler settle for a few minutes before a good healthy blowdown. Hope to see you at Nockamixon in October.

[Ofcalipka]

Thanks. I have a condensing system as I operate in saltwater and was not sure how much to add to acheive the correct pH.

[S. Weaver]

...
One thing I noticed is the website recommends draining the boiler if it will not be returned to service within 24 hours. I think full wet layup is the preferred method for all shutdowns throughout the season, and drained/dry layup is only required over winter months to protect from freezing. It takes little effort to put my boiler in cold wet layup, and takes me about 5 hours to put the boiler in drained/dry layup. Drained layup with a wet boiler invites corrosion, and drying it properly takes the time. Drained layup with an inert purge gas would protect against corrosion, but I doubt many of us steamboaters can do that.

Any comments from other forum members?

Fred, we drain our locomotive boilers if they will not be returned to service within twenty-four hours, and we recommend that to our customers. We do it while the boiler is still warm and remove the lowermost and uppermost washout plugs. The latent heat in the steel dries the boiler in a matter of minutes. We then cap the stack and place a heatlamp in the firebox. This procedure has made a marked difference in oxygen pitting of the tubes and flues.

[fredrosse]

The locomotive boiler has horizontal tubes, a massive amount of metal, and usually several feet of elevation distance between the bottom washout plug and the open vent at the top. The big elevation difference between the inlet and outlet acts like a tall chimney, promoting purge air to circulate and dry out the boiler. So when the loco boiler is drained, there is indeed an opportunity to get all the tubes dry, and if there is some water left standing at the bottom of the boiler it will only cause some rust on a plate that is very thick, about 3/4 inch or so. Since the tubes generally have a wall thickness that is only a small fraction of the main boiler shell, corrosion on the tubes is the main concern.

The boiler in a drained and dry condition is the best for layup, however I have found that achieving this with a small launch boiler, just using the residual heat in the boiler metal, does not work. A small launch boiler has much less mass, and cools down much more quicky than a railroad locomotive boiler.

Many launch type boilers, such as a VFT type, have their washout plugs mounted a little above the bottom tube sheet, so when drained there is water standing there, in direct contact with the tubes. If vented to atmospheric air, this is the ideal condition to promote corrosion on the tubes. A launch with a watertube boiler would stand a better chance of getting the tubes dry, as any residual water would probably lay in the bottom drum, however many watertube launch boilers have hotizontal watertube runs, and a small slope may prevent full drainage of these tubes.

Some have recommended building a small fire in the drained boiler to dry it out. No doubt this can dry the boiler, but it is, in my opinion, way too risky to build even a small fire in a drained boiler. Differential expansion could easily cause high stresses, leaking tube joints distorted boiler metal, etc.

[S. Weaver]

... Aware of the differences. Just could never advocate long-term wet lay-up. Wicking, 500 watts in the firebox and capping the stack could dry out a VFT in short order.

BTW, agree on the TSP. Good stuff.

[fredrosse]

I will try to get some data on the dryout methods. One potential problem is the many connections, some of which can pocket water inside an elbow or up/down piping. Another is leaking from piping that should be isolated, but has a leaky valve. When I put my boilers in dry layup, I blow all the piping connections with compressed air, and disconnect the feedwater line from to boiler, etc.

On another issue, I bought some boiler treatment stuff at a trade show, but I am afraid to use it as I don't know what is in it (Not that I would have any idea what it would mean to know what is in it, but at work there are some water treatment guys who might know). It is labeled "LSB8000", for scale gauge live steam locomotives. Instructions say it removes scale and corrosion products. Does anyone have any experience with this stuff? Did I buy some "Snake Oil"?