Well, it is brass with a high temp polyethylene float. It has to be mounted
close to vertical to open. I was worried that when the engine cooled and
the pressure dropped it would act as an anti-siphon valve and let air back
into the system but after playing with it that does not seem to be a
problem. I do believe however that after the system is purged it would be
a good idea to close the outlet valve just in case and just open it when I
am changing out the coolant.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Glenn Ashmore" wrote in message
news:VANBf.13635$Dh.2158@dukeread04...
I will go by Grainger this morning to pick one up. They are only about $7.
It is made by Watts Regulator so it is probably red brass but in a normal
engine room environment on the closed side of the cooling system it should
be OK. I will dissect it and report back.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"RW Salnick" wrote in message
...
I would sure be interested in how this device works out, Glenn. Is it
made of material suitable for marine service (that is, no mild steel, etc?

bob

Glenn Ashmore wrote:
OK. I have hung the water heater hose from the engine room ceiling. I
am still worried about trapped air but just discovered Grainger part #
4A820. It is a float type automatic air vent made specifically for
removing air from hot water heating systems. It vents air until if
fills with water. Says it is glycol compatible, 240F max working
temperature and works to 150 PSI. The vent can be sealed with a little
screw so once the system is purged I can seal it off and it is only 3"
high. Looks like the perfect solution. .