Black Pipe Returns & Boiler Issue

RobLC

<span style="font-size:12pt">Any input on this subject is appreciated.  </span>



<span style="font-size:12pt">We have a steam boiler that uses natural gas for fuel.  It runs well.</span>



<span style="font-size:12pt">We have removed all the exposed return black piping because some spots are showing signs of corrosion.  Of the black return piping that was removed, signs of scale buildup has occured.  I </span>



<span style="font-size:12pt">I carefully removed some loose scale from the bottom of the boiler with a long spoon-like instrument. </span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">It’s an old boiler, from the 1950s, maybe earlier.  The guys from National Grid make fun of it until they turn it on for inspection and are surprised that it hums and burns clean and safe.  The water in glass does not surge and we get great heat on 3 different floors.</span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">Our question:  Should we just replace the return condensate piping and not disturb the sediment at the bottom of the boiler?  We are concerned that stirring up the scale might cause a blockage in one or more of the internal boiler tubes.</span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">One more: Will skimming be adequate enough?</span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">I have tried to provide enough information that would be required to address this issue.</span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">Thanks for any input and guidance.</span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">Robert</span>

Big Ed_4

Old Steam System

Corrosion in your system indicates the system has steam leaks over years.( steam leaks + fresh makeup water = corrosion + solids ) The boiler is 60 +years old , the return pipe is 60++ ? That old gas system does not have the safey controls of today's units .. Nor does fire on the same efficency of today's units .. Fuel cost is higher and more of a concern today too ..



Now to Answer your question .. You can flush the solids out with water . Skimming may be needed after Any replacement of iron pipe ,boilers or oil is introduced some how in to the system , skimming removes any floating materials ..

RobLC

Thanks, Big Ed...

Black piping was replaced about 15 years ago but there is some sign of corrosion because basement is damp and the returns run along the floor - - they used to be buried in the ground.

I was thinking of introducing water through the pressure relief fitting threads with the bottom outlet on the boiler open.  Would that do it? 

I would also skim the boiler through the pressure relief fitting threads.

Thanks for taking the time to answer my question.

Robert

RobLC

Thanks, Big Ed...

Black piping was replaced about 15 years ago but there is some sign of corrosion because basement is damp and the returns run along the floor - - they used to be buried in the ground.

I was thinking of introducing water through the pressure relief fitting threads with the bottom outlet on the boiler open.  Would that do it? 

I would also skim the boiler through the pressure relief fitting threads.

Thanks for taking the time to answer my question.

Robert