Holding Tank Discharging
Sometimes, our designs just miss something... this was one of those times.
| In an effort to correct the design
problems all ready shared, the discharging lines needed redone.
The
macerator pump was first removed from the holding tank and the plumbing
required to make the change was laid out for fitting and glueing
together. Working thru the small door is not easy...so most of
the
plumbing tree was build outside the boat on the work bench
and then installed in the boat. The goal was to retain the macerator pump for self discharging into the yard cleanout... but avoid the previous problem of having to run the pump during a normal pumpout and the resulting problem of waste left in the lines not able to back drain past the pump into the tank and causing a slight if if not disconcerting spill when the pumpout hose was disconnected. The 13 gal holding tank sets on a platform just beyond the rear bulkhead in the wet locker. The fill, discharge and vent lines are made to the tank via holes cut into the bulkhead. |
 |
All fittings are 1
1/2 inch pvc except for the
discharge from the
macerorator pump which is 1 inch. Because the tank sets at a
slight aft slope... a tube was glued within the male adapter fitting
that screws
into the tank. The tube is made
from 1 1/4 pvc and its end
turned down on the lathe to match the inside diameter of the 1 1/2 inch
male adapater. An end cap was also machined and glued
within the end of the tube. A 1 1/2 inch hole was drilled into
the side of the tupe near the end and positioned down so that
it increases the useable volume of the tank. The tube and male
adapter are screwed into the tank awaiting the plumbing tree.
The tree fully assembled up to the center ellbow is then glued to the nipple previously installed in the male adapter screwed into the tank.
Note: To allow room for the valve and the entire fittings needed for the tree, the discharge first needed turned downward to gain height.
The macerator pump in energized thru a relay only slightly visible in the picture to the right of the pump. After the tree is in place, the pump is screwed to the bulkhead.
The valve is in the normal pumpout position. To use the macerator pump, the valve would be closed.
In the pic, a white small wire is visible to left of the pump. It runs up to a small light with a switch for backlighting the tank to check its level.
The tree fully assembled up to the center ellbow is then glued to the nipple previously installed in the male adapter screwed into the tank.
Note: To allow room for the valve and the entire fittings needed for the tree, the discharge first needed turned downward to gain height.
The macerator pump in energized thru a relay only slightly visible in the picture to the right of the pump. After the tree is in place, the pump is screwed to the bulkhead.
The valve is in the normal pumpout position. To use the macerator pump, the valve would be closed.
In the pic, a white small wire is visible to left of the pump. It runs up to a small light with a switch for backlighting the tank to check its level.