Re: Anybody who knows BilgeWatch sensor or similar?
Chris, you bring up a very good point.<br /><br />I have looked at other, similar, bilge switches that react differently depending on the conductivity of the liquid between two contacts. The BilgeWatch seems to be such a sensor. Couldnt find too much info on BilgeWatch, even from the manf website. The way other systems work is that hydrocarbons will float on water. As the liquid level increases the current that flows between the contacts thru the hydrocarbon doesnt meet the criteria for switching the bilge pump on. If water is introduced, the liquid level increases, eventually the hydrocarbons float above the contacts and water shows up on them with the conductivity the switch is looking for and the pump engages. A bilge pump draws liquid from the bottom of the bilge, were the water is. As the water pumps out, the liquid level drops, and hydrocarbons once again cross the contacts and the switch turns off, in theory never pumping the hydrocarbons out.<br /><br />The switch I am using does not sense the different conductivities. Instead, it is completely sealed and only senses the level of a liquid
I think. I need to test it on hydrocarbons to see if it will work only with water. It doesnt say on the manf website. The vertically mounted sensors have an advantage over a pair of sensing leads in the same horizontal plane. Here it is:<br /><br />
http://www.msc-emd.com/sensaswitch.shtml <br /><br />Regardless of the bilge switch used, an inline hydrocarbon (and glycol
antifreeze?) trapping filter is a good idea. I have been talking with the folks at Parker (Racor filters), Mycelx, and Abtech about their hydrocarbon trapping polymer filter elements. The elements are more expensive than I had thought. A 20-in Abtech goes for about $100
just for the element. Mycelx seems to be about the best so far because they have a 10 element for either 10gal/min ($38) or 20gal/min ($60). Neither element has any flow restrictions and traps 99% of the hydrocarbons and glycol on 1st contact, and it does not hold water. Ironically, the cheapest way to trap hydrocarbons in high-flow applications to 400gal/min is a filter designed for use below storm drains on streets to trap oil that leaked from cars/trucks and washes down the drain after a rain. They cost about $120 for a 13 x 13 x 14 box stuffed with Abtech popcorn, the same polymer that is in their in-line filters. As I find out more about the products and their applications I will post the info here. Bulk polymers are cheaper ($600/55lbs) and may be ok to use in a bag filter. You need only 1.5lbs for a filter
about $16/worth. Abtech was interested in this application.<br /><br />Every boater should have something onboard to catch hydrocarbons that would pump overboard thru a bilge pump, but it shouldnt have to break the bank. The bilge boom/sock/pillow I mentioned above will go a long way in absorbing and hold hydrocarbons and they are inexpensive.<br /><br />For off-the-shelf stuff, a $20 inline filter canister with a $38 Mycelx 10 x 2-1/2" filter will work for most bilge pumps at 10gal/min. I higher flow $45 canister and a $60 Mycelx 10 x 4-1/2 filter will cover just about everything else up to 20gal/min. My help!-Im sinking bilge pump kicks out about 70gal/min. Im not going to filter it because if its engaged the only thing in the ocean, besides me, that I care about has teeth.
