Question

Joe V_2

My boss asked me a good question after we fired our boilers on diesel for the first time in two years...If we developed a fuel leak in the boiler room, what would be the best way to stop the fuel flow quickly and automatically?

We have three 650HP Hurst boilers.  Are there safeguards already in use for this scenarion?

jpf321

perhaps it matters....

whether this is 2-pipe vacuum draw system (the burner pump is pulling fuel) or a gravity system. I don't know much at all about this, but I think a tank located below your burner would require a 2-pipe draw system and a tank above your burner would be a gravity system. I'm just asking because it may make a difference in answering your question by someone that does know about this.



I think that if is a 2-pipe, a leak would be detected quickly because you start to draw air into the burner through the leak. If the leak was severe enough, perhaps the oil would simply drain back into the tank since in theory the tank is below the leak.



In a gravity system, the leak may not affect the burner much, but it would surely make a mess on the floor, this is probably the reason for your question.



Perhaps something along the concept of  a hartford loop or false water line would be helpful. Afterall that's exactly why a Harford loop exists, if there is a major leak in the returns, the water does not empty from the boiler. Along the same lines, if you have a major leak in your oil lines, you don't want the oil to drain out of your tank. And another benefit is no moving parts, and only requires some copper and a couple flare connections. The only oil that would leak is the oil between the "harford loop and the burner" in theory you would place this loop very close to your oil tank. You may need to pipe in a priming tee so that you could prime the loop (akin to a false waterline) .. a Hartford loop is self priming since it collects condensate from the equalizer and officially, it's below the water line .. uh oh .. I just realized that your oil tank outlet must be entirely above the burner, hmm I guess they usually are in a gravity or the gravity wouldn't work either.



Yep, I think I nailed it .. a "JPF Oil Loop" (I do get to name it right? Or is this already common practice) located as close as possible to the oil tank for a 1-pipe gravity system and consists of 2 vertical risers connected at the top by 2 elbows and a nipple (or simply a 180deg bend in copper tubing) which rises no higher than your fullest mark (how about 2" below) on the tank. To make things easier, pipe in a priming T at the highest point which has a "nipple" that extends 2" above highest full mark.



It feels good to think well.