Solar Flat Plate draindown system

[Rancher]

What's that thingie at the highest point on a flat plate solar hot water system, that lets the air/steam out but closes when the water hits it.

Is it the same as a watts air vent that's used on an air scoop?

Rancher

[Bill Arden]

Spyrovent?

[BigLou]

rancher,
in a word YES. Its not the same thing as a spirovent however. Its just a vent with a float.

Lou

[Rancher]

BigLou,

Thanks, do you have a source?

I'm putting mine back on the roof after a 80 mph windstorm, just used a check valve before, thought I'd do it right.

Rancher

[BigLou]

Rancher,
here is a link of what you want. I get all my stuff at the local supply house, make sure that any air on both the supply and return lines can get out

http://www.taco-hvac.com/en/products/Air+Vents/products.html?current_category=87

Lou

[Rancher]

Thanks,

The Hy-vent is exactly what I have avaiable to use except it is the Watts brand.

But I don't know how it operates, I understand there is a float inside that closes it off when the air is fully purged, and it kinda makes sense that it re-opens when the water drops.

I want this for freeze protection, i.e. drain down at night.

Rancher