Boiler piping schematic with pressurized storage

[tuolumne]

Is the residual liquid history? The tanks have been filled, drained, and a pressure washer stream played around the inside. Since then they have sat for more than a year. I have been told that the steel is porous enough to retain some of the propane. Will proceed as safely as possible.......

 

[Sting]

Is the residual liquid history? The tanks have been filled, drained, and a pressure washer stream played around the inside. Since then they have sat for more than a year. I have been told that the steel is porous enough to retain some of the propane. Will proceed as safely as possible.......

Good - rumor is correct - I have been flashed from some very old tanks open for a very long time because I was stupid and didn't take the time to correctly do a RUSH job :>)

 

[steam man]

I have cleaned and certified many large industrial fuel tanks for welding. In my liquified natural gas days I had to test for combustibles many times. I know the "little guy" at a small shop does not have the resources for testing and will resort to the above schemes mentioned. I think you are probably 99.99% safe with all the prep work that has been done. Its the unknown that's risky and many welders have learned it the hard way. The only proper way to do this is to have the tank tested with a combustible gas detector to know exactly what the atmosphere is inside the tank. Aside from that, filling it with water would be the next safest situation.

 

[solarguy]

I'm not sure about anything other than I'm dam sick of snow

When we've filled the tanks w/ water & drained them I've always taken a wiff before proceeding.
For what's it worth, the nose knows.
If you fill & drain a tank & still smell propane, fill & drain it again or all bets are off.

 

[tuolumne]

I had some more time to work on the boiler this afternoon. I now have the supply, return and bypass piped at the boiler. The danfoss is visible at the rear, with a balancing valve on the bypass. I have a temp/pressure gage on the supply, and a temperature gage at the return. I also built the sidearm today. Once I got more pipe layed out, I realized that the sidearm would only take a few extra feet to tie in. I used 1-1/2" outer pipe (boiler loop is 1-1/4) with a 3/4" pipe on the inside. This connects the cold inlet and hot outlets of the indirect storage tank. I had to ream out the stop in the reducer coupling to get it to slide over the 3/4" pipe. The picture at the bottom of the tank shows the cold coming in, the bottom of the sidearm and a drain. At the top you can see the mixing valve to temper domestic water. The valve to the left is to supply untempered water to the dishwasher. The domestic loop still held pressure when I was done, so that's a good sign! I put a valve at the top of the thermsyphon loop...I was worried that water might jump directly from the cold supply to the hot without going through the tank. Tank outlets are 1-1/2", versus 3/4" in the sidearm, and the valve will let me sqeeze it down to a very small orifice. Any comments?

 

[tuolumne]

I finally have the boiler all piped and tied into the house distribution. I still need to either tie out to a gravity overheat loop. Does anyone know of an online source for an automag valve? I also need to pipe the storage buffer tanks...waiting for warmer weather so I can fill with water for welding and leave them that way. I just got my box of electrical goodies today, so that's the next challenge. I have a radiant mixing block that controls the radiant zones, a zone valve controller, and a switching relay for the other pumps. I need to make sure that all of these components can get along with each other and the EKO as well. the four valves going to nowhere are for the bufer supply/return, and for a future fossil fuel boiler that I hope I'll never need. I had asked previously with no response...what can I use to read thermocouples or RTDs or something on wire for temperature measurements in the buffer tanks...human readable that is? I plan to use a capped copper pipe in each tank. Should I stuff insulation between the gauges to prevent convection in the pipe?

 

[jebatty]

check http://www.automagzonevalve.net/

 

[tuolumne]

Thanks for the link Jim. They told me that my local F.W. Webb has them in stock. I don't know why my searches came up empty before.