Re: Boiler leaks - Any ideas about this one
Posted by: Jeff Theobald
Date: November 17, 2006 04:45PM
I too have a boiler that gives this sort of trouble, it has never been scorched, but has given trouble from new, at about six months old it suddenly dropped water through the fire plate, when the auto shut down the fire, after first firing from cold, then it would do a week or two without trouble. In the end the boiler was removed and returned to the builder who fitted ferrules top and bottom, the boiler was filled with water and leak compound and hydraulic tested to 1000psi, and was totally dry.
From that day on it was tight for about five years, being tested each year, and then out of the blue it did it again. I then took note of what started the leak, and noticed that it would occur when first steamed, if allowed to come up on the automatic, and then be left standing while getting passengers in and preparing to move off, it would also do it on a long downhill run when still pumping water but with the burner shut down on full pressure. As you say water would pour from the ventures, but I found that if you could get the fire back on, it would instantly seal, and not show the symptoms again for some time.
I spent a long time flushing and cleaning the boiler, I ran an ultrasonic over the shell and the results showed no wasting, again the boiler was filled with water and leak compound, pumped up too 1000psi and again all dry. Again the boiler was put back into service doing about 2000 miles a year for another 12 years, when again it did the same thing during the tour in Devon. Careful driving for the week got us through, on returning home, again a complete clean inside and out, the same treatment as before, and it has been tight since.
Why does it do it? Well I think oil gets back to the boiler getting between the tubes and boiler plate, if the boiler has not gained an even temperature or the fire plate is chilled, movement takes place between copper tubes and steel plate, promoting the leaking. This same boiler is now over 20 years old, still no sign of wasting, and still passing a 1000psi test.
Hope this helps, all the best, Jeff.