over pressure problem with storage

[Gasifier]

My bad guage was also a guage with the two needles - the temp part seemed to still be working, the pressure one seemed to gain 20 pounds for some reason (there must be a wife joke there somewhere, but I won’t go there…). First I was thinking it got dirt in it, but from another experience I think that would lead to a low reading. The second one I put in is solely a pressure guage. Could there be a check valve or backflow preventer in the system between the two guages? Then again there would have to be two checks or blocks in the system to get two different pressures - in my mind anyway. This is quite interesting, I’m trying to get my head around what I’m planning for next year here, it’s seeming like storage & expansion might end up being the harder and maybe more $$$ part of the whole thing.

You are correct. Storage and expansion will be more $$$. But, it will be worth it for you. Thanks for the information. You are also correct that there must be a joke in there. :lol: You are also wise in not going there.

 

[cheapsx]

Do the same rules apply for sizing non bladder tanks? If I want to get my storage (500 gal) up and running I need to use the non bladder tank I have made. It will be used in combination with 2 #60 bladder tanks. My plan is to allow minimal water in the tank and charge with air to same psi as the bladder tanks. My non bladder tank is 50 gallons and system volume is just under 600 gallons. I can add more capacity to the big tank if need be. I plan on using bladder tanks in the future when the $$ is there for them unless this works really well and requires little fussing with.

 

[ewdudley]

Do the same rules apply for sizing non bladder tanks? If I want to get my storage (500 gal) up and running I need to use the non bladder tank I have made. It will be used in combination with 2 #60 bladder tanks. My plan is to allow minimal water in the tank and charge with air to same psi as the bladder tanks. My non bladder tank is 50 gallons and system volume is just under 600 gallons. I can add more capacity to the big tank if need be. I plan on using bladder tanks in the future when the $$ is there for them unless this works really well and requires little fussing with.

You've got it.

One way to use a non-bladder tank is charge it to atmospheric pressure by isolating the tank an draining all water. Then the let system water back into the tank and add water to system until system is up to whatever the pressure should be for the temperature it's at. This is a good way to go because it's easier and it's pretty much foolproof, but it takes a lot bigger tank because a lot of the tank volume is used up just to bring the system up to pressure.

But if -- as you've described -- you supply compressed air to the tank and drain water and add air until the tank level and pressure are correct for the temperature of the system, then the volume requirement is the same as for a bladder tank because you've removed water and added air to reclaim the 'wasted' tank space. It takes more management and understanding but you can use a smaller tank. Also you need to be careful when working on the system to isolate the expansion tank so it doesn't blow its charge back into the system.

 

[Gasifier]

Should I be concerned with my oil boiler being at 22-23p.s.i. and wood boiler at about 17-18? Is the 22-23p.s.i. to high? This is with my wood boiler and storage tank sitting at 175 °F tonight. Oil boiler is about 75 °F . How are you making out with pressure now Erie? Did you end up changing a few things?

 

[cheapsx]

This looked like a good thread for this question. Can to much expansion in a system be of some harm? I have (not totally hooked up yet) a total volume of 600 gallons I planned on using a 50 gallon propane tank and two # 60 extrols for the expansion. I just came home with another 50 gallon propane tank (free) and was thinking about mating that up with the other one. I assume this would make for less of a pressure increase and is that not a desired effect?