Emergency Boiler/Burner Shut-off

I have figured out a way to make a low water emergency shut off sensor that utilizes purchased components. The issue I have is that you really can't see the boiler level sight glass when driving - even if you add a mirror. I guess in the 1900's you would develop a feel for when to turn off the bypass water system and pump water back into the boiler. I can't imagine that I will use the Lykamobile that much to get the experience to know when to do this at the right time to avoid cooking the boiler. This modification really is a "peace of mind" improvement so that I don't have to worry. The first issue was searching for a suitable circuit. I found a circuit that can be used to either fill a reservoir or drain a reservoir. I needed a circuit that could drain a reservoir. The thinking was instead of turning on a pump to drain a reservoir, I would use the circuit to turn on my pressure sensor. The pressure sensor controls the burner which makes the steam. Once the steam is to 250 psi in the boiler, the pressure sensor disconnects the power to the burner. So by controlling the electrical power to the pressure sensor and turning it off when there is a low water level in the boiler will safeguard the boiler. Below is an image of the circuit board with annotations of how I set it up.

Next I needed to make a water column with at least two ports and position this column in parallel to the sight glass boiler water level. To do this I had to put a couple of T's in the copper lines and acquire some heavy duty copper pipe from our local building supply house. Below is the T at the top of the boiler along with the flare fittings. You will need to double flare the copper for a proper seal. This will necessitate finding a double flaring tool.

The bottom copper line was cut in two with a small section removed to allow for the T and flare fittings.

And by trial an error I bent the copper tubing to fit to the water manifold that I mounted on the opposite side to the boiler. This was the most convenient place to mount the manifold. I had to make a bracket from 2 inch x 1/8 inch flat stock steel cut to the needed length. See below pictures.

I found some spark plugs that were threaded instead of the push on connection, the most important consideration was to get spark plugs that would protrude into the manifold far enough. These spark plugs have a 25 mm threaded reach. You also need to cut away about 10 mm of the thread to expose the ceramic insulator and electrode. This is necessary to prevent chemical buildup on the spark plug. Next I mounted the circuit board and wired it up to the electrical box provided by Steam Traction World.

You can see that I am only using the lower two spark plug positions. I positioned the bottom of the manifold about 2 1/4 inches up from the frame. This positions the number two spark plug just above the lowest portion of the visible sight glass gauge. 

For the upper two positions on the manifold I am thinking about using them to control the bypass water circuit automatically via a normally open solenoid placed in the copper tube bypass feed line. When the water level goes down past the second highest spark plug it would trigger the solenoid to close and start the filling of water into the boiler until it reached the upper most spark plug. This idea would necessitate a totally different circuit board, one similar to the Series 1 Lykamobile that would monitor and control all functions sensed from the 4 spark plugs. 

I should also note that I had to separate all my lighting circuits grounding wires from the frame. This required me to run a separate ground to each light. My first idea was to use the frame as the ground by attaching a grounding strap from the battery to the frame. Doing this messes up the water level sensors making the circuit board non-functional. Below are the parts I used to make this emergency Boiler/Burner Shut-off.

The following was purcased on Amazon:

(1)    B0181RL1GA Circuit Board by SMAKN                                   $12.00

(1)    uxcell 85x58x33mm Electronic Waterproof IP65 Junction Box  $ 8.89 

The following was purchased from McMaster-Carr:

(1)    5975K46 Aluminum Manifold                                                   $47.31 

(1)    50785K222 High Pressure Right Angle 1/4 NPT Fitting          $ 4.90 

(3)    50635K381 45 Deg. Flared Fitting 3/8" Tube to 1/4 NPTF      $ 2.96 each

(1)    50635K534 45 Deg. 3/8" Tube T Connector                            $11.15

(6)    50635K564 45 Deg. 3/8" Short Nut for 0.065" Tube Wall       $ 2.70 each

(2)    50785K68  High Press. Adapter Fitting 3/4 Male x 1/4 F       $ 5.35 each

(1)    50785K43  High Pressure 90 Deg. 1/4 NPT Female x Male   $ 2.50

The following was purchased from Brillman Co (www.brillman.com):

(4)    B9005-001 Spark Plug Adapt. 1/2NPT to 14mm Gasket Seat $6.00 each

The following was purchased from an auto parts store:

(4)    Accel 578-4 Spark plugs                                                     $16.57 set of 4

 

You will also need about 5 feet of 3/8 inch heavy duty copper pipe/tubing, steel flat stock for the bracket and of course wire. The total that I spent for this emergency boiler shut-off was about $175 (not including any shipping costs).