Vacuum pump to winterize

Gkopan

 Would a vacuum pump work instead of blowing out the water lines?

ScottG

Probably not attached to the city water port, as there is a check valve installed there.

I'm curious what the perceived advantage is to using a vacuum pump.

pthomas745

I've thought about this sort of thing, too.  In the non-Nautilus trailers, why not drain the trailer and use some sort of suction on the drains under the trailer?  If it works for the Alde glycol change with the shop vac method, it would seem that drawing any extra water out from the bottom of the trailer would be more direct than trying to blow air through the various loops of the city water setup.  Not sure if or how this could work for the Nautilus trailers.

@Gkopan, we await your Tab Science experiment or thoughts about this.

westernstates

I use a compressor set at 20psi to blow out the water lines. I would be concerned if one can't adjust the negative pressure to the same 20psi max that a vacuum could possibly collapse some components.

Horigan

Vacuums only go down to -14.7 psi at sea level.  Less at higher altitudes.  I doubt a vacuum pump could even achieve -14 psi.  Some soft lines could collapse at that negative pressure, but not the pex lines.  You get a lot more airflow through the lines with compressed air.

Gkopan

Related, Is there a diagram/map of all the pex lines? ('21 400 boondock) Wondering especially where the deeper "dips" are that would be most subject to having water remaining after blowing out (to insulate somehow?) I'll be in Bryce Canyon beginning of May and want to ready for freezing temps at night.

pthomas745

I use a water pressure regulator with my compressor for the blowouts.  When I think about "suction" to pull water from the lines, I'm thinking more about how the shop vac method "sucks" glycol from the glycol loop.  Owners who have done that method say they let the shop vac run for a while, which to me seems to either "sucks' the old glycol out, and eventually the air traveling around the loop simply evaporates whatever is left over? 

If I could send warm air through the plumbing lines, I would assume that would evaporate practically all the water that might be left over after draining. Over time, of course.