Home |
Search |
Today's Posts |
#17
|
|||
|
|||
Windjammer wrote:
Peggie, I agree that this would not work for everyone, but it is not that bad an idea. Many holding tanks would be capable of handling a small internal pressure. In my own case, the tank is solid fibreglass with a 1/2" well secured "Starboard" cover. A calculation would have to be done on the cover because it is the weakest part - It is well secured around the edge, but does span about 30" in places. The fibreglass part of the tank is as strong as many small boat hulls and well capable of handling some pressure. My tank will self drain to about 1/3 full which leaves about 10" to displace - this would take a pressure of about 0.36 psi to empty. I imagine that many tanks see a higher vacuum than -0.36 psi when being pumped out, so would probably handle this quite easily. To do this, I could stuff a little putty or ?? into the vents, then use a cheap air pump with a gauge to slightly pressurize using the pumpout connection. All this of course while offshore only! Terry may or may not have been serious, but sometimes there are good ideas that don't follow conventional practices. Keep an open mind - A system designed to work this way would eliminate the need for a macerator pump - one less expensive electrical item to go wrong. GM I'm very serious, except for the requirement to wear protective gear. I take it you calculated your pressure requirement. I was unable to measuer the pressure requirement with my tire gague, it's so low. I used plastic ball valves in the vent lines and a shraeder valve "line flush adapter" RV accessory for the air connection, screwed into an automotive radiator flush adapter. The first time, I used wooden tapered plugs to seal the ventlines, another piece of equipment every boater should carry. The cost of a macerator pump is, of course, the main motivation. Terry K |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Holding tank vent blocked | Cruising | |||
Where is holding tank vent thru-hull on 1989 Carver 28 ft. Montego? | Cruising | |||
Moving a holding tank vent | Cruising | |||
Holding tank cradlle | Boat Building |