Lavac says that "The bottom of the pump must not be mounted at a lower level than the top of the bowl." In another paragraph, they specify the pump inlet to be no lower than the bowl top. Not sure what they're trying to prevent here but you may want to ask Blakes, or reconsider. It may not be an issue with you pumping directly to the tank?Bill Cochrane wrote:Randy et al...I'm following this discussion with interest as I have a Lavac awaiting installation and I'm trying to figure out how to do it without (or maybe with) having the bulkhead look like a chandlery's plumbing display wall. I'm complicating things with a y-valve to direct discharge as well as to the tank. Ideas and photos of installations would be very welcome.
The pump should end up just above mid bowl level.
I'd also want the pump secured to a bulkhead or otherwise fixed in position. Even if the hose clamp was enough to resist the hose popping off from pumping action, I'd be a bit concerned with fatigue from flexing.[/quote
The fellow at Lavac told me that the pump only needs to be higher than the head's outlet. It worked perfectly last night with the pump located at about mid bowl. IF mounted too low the water in the bowl will just leak past the pump and not remain in the bowl. But as long as the outlet hose makes a loop slightly higher than the bowls water level nothing drains out till it's pumped out.
I believe their main concern is with flooding caused by below the waterline installation. Not an issue with my install as the discharge goes only to the holding tank and I always close the seacock after use. My pump will be right at the rear of the head attached to the head's outlet with an 8" piece of tubing. The pumps outlet will then travel up to slightly higher than the head's seat and back down to the holding tanks intake pipe. This pipe sits just below the heads base. So far, at home, I have only setup the pump attached to the head by the 8" of 1.5" tubing and it works perfectly. Tonight I will setup the pump's outlet tubing and the water inlet tubing with the air inlet valve installed in the intake tubings high point, to get a feel for how much water each (two sizes supplied) allows to flow in with the lid shut. With the joker valve at the pump's outlet and a very short run both to the pump and to the outlet hoses high point the pump simply sucks the bowl completey dry.
After I get the pump installed, inline with the hose, I will fabricate a bracket for pump mounting and secure it to the same surface that the head sits on just behind the head. My main issue was with getting enough room to bend the 1.5 tubing into and out of the pump. This method solves that issue.