schedule 40 pipe

[rayi]

Will schedule 40 pipe be OK for the drains on a hood and the piping to prevent vapor lock in the preheater. The pipe is out side of the hood. SS goes from the preheater to the float box.

[Dennis H.]

I actually used sch 80 pvc pipe and fittings, 1/2" for small hood and found that very quickly it got soft and started to deform.
I replaced it with some copper and a barb fitting and hose to drain.

I used all copper or SS camlocks to hook up my hood. After seeing the drain fittings do what they did and that PVC pipe is rated for less than 100 degrees I would look at other options.

[BreezyHill]

Will schedule 40 pipe be OK for the drains on a hood and the piping to prevent vapor lock in the preheater. The pipe is out side of the hood. SS goes from the preheater to the float box.

NO! PVC and preheaters are a disaster waiting to happen. Las season one late night I fell asleep in front of the evaporator, I a woke to the sound of the evap feeder tank running a 1.5" stream of sap onto the floor and I was soaked. My preheater is a 1.5" Stainless milk pipeline in a duct that the steam from the hood travels thru. The sap exiting runs around 185 to 190. I had just filled the fire box a must have nodded off. The fire box had only gone a few minutes and the evap was going great.

Seems the preheater was working so well that the pvc that was used to connect the bulk tank to the SS pipe got to hot and sagged. It was a good inch below the SS pipe and the rubber sleeve that was clamped on had slipped of the pvc. I lost around 25 gallons of 14% sap before I got the tank valve closed. I realigned the pipes for the night and finished boiling and in the am ran SS back to the tank adapter fitting.

No pvc on my system ever again and I added an alarm to the auto draw of system in case I fall asleep again.