Transfer line issue

[maple flats]

I have an inch and a half TF line that causes problems every year. The tank sets 900' off the road and the TF line goes over a friendly neighbor along a swamp and then down thru a cold ravine to get to the road. Every year the line freezes in a colder snap and then takes 2-3 days to thaw. I was wondering, does anyone use a vacuum break to allow a TF line to drain better. If that would work, I'm thinking I could build a platform/support about half or 2/3 across the swamp, climbing from the sap tank to the platform, then fall on an easier slope to deal with to the road. Then if I could put a vacuum break at the high point I could better drain the line, the steady climb portion drain back to the sap tank and the rest to the truck. Would this idea work?

[BreezyHill]

What about using a tee and a stand pipe with a check valve on the end. I have seen this work to drain water lines fed by springs for cattle and homes.

When the line is under pressure or flow the check is closed and when drained the check opens and makes the flow empty much faster.

[Spanielslovesappin]

I have a section that will require a transfer line that will rise then fall to the tank; i plan to use a vacuum breaker. I would think it would work well in this application but have not actually tired it. The only potential hang up i can see is that if its right around the freezing mark its possible the vacuum breaker could freeze open or shut. A stand pipe with check valve tee'ed into the line at the high point is the same basic idea only you would need to calculate the pressure in the line at out high point to know how tall of a stand peep would be needed to prevent sap from reaching the check valve... otherwise you would have the same potential issue with the vacuum breaker freezing (check valve is the vacuum breaker in this scenario the stand pipe keeps the sap from reaching it). Try it out i guess... locate it in the sun and paint it black if possible??

[BreezyHill]

One could use pvc 10' section with a double elbow and another length of pipe to bring the check back down to eye level. Install a ball valve prior to the check so that it could be closed if the check would freeze open. A brass check would allow the use of a torch to thaw if need be.

We had a vacuum breaker when we were pumping sap and it seem to freeze open all the time due to the vapor in the line my dad figured. It was my job as a little guy to take the torch and warm it to be sure it was thawed. I remember getting soaked many times when he turned on the pump but the sap would finish the thaw job when it was frozen.

I was figuring the stand pipe would give an air block between the sap and the check to keep it drier or even not get contact with the sap.

Ben

[Spanielslovesappin]

Ah, air gap...Clever thought... curious how well it would work?