Re: automated baths

["Richard Challis" <richard@xxxxxxx>]

----- Original Message -----
From: "Hawes,Timothy Edward (GEG)" <haweste@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Thursday, November 13, 2003 10:55 AM
Subject: RE: [ukha_d] automated baths

> a secondary precaution, you may want to add a timer so that, say, if
the
water level sensor hasn't closed the inlet valves after 10mins, you close
the valves anyway. This would serve two purposes (a) prevent or limit the
amount of the overflow if the > sensor fails (b) stops you wasting water
if
the drain valves fail to shut (like leaving the taps on but with the plug
out)

A nice precaution.

>
> 40mm solenoid valves are available, but usually reserved for
industrial
applications (read: expensive). You may want to consider multiple 15mm
solenoid valves on the drain to ensure the bath doesn't take all evening to
empty :-)
>

Be careful what valves you use, quite a few water valves use the mains
water
pressure to "assist" them to open. (Pilot style) Probably the
header in the
bath would work anyhow. The other thing is that a valve with pilot assist
would have  a small hole that would be easy to block. This could also
happen
with using multiple 15mm valves. Even some industrial valves have fun with
"slightly" dirty water.

Regards

Richard