bilge check valve

[patrick]

can anyone tell me if putting a check valve in the outlet side of the bilge pump would be a very bad idea. it is frustrating when you want a dry bilge and the pump back flows about two inches of water back into the bilge. besides it getting jammed with debri is there any other reason.

 

[Mike Elmore]

I did it

I went ahead and did it at the beginning of this season when I installed my rulemate pump.I can't remember the exact circumstances, but I put a check valve in the run up from the bilge to keep water from running back down after the pump stops and have had no problems at all.The concern here is that the weight of water on the "outside" end of the check valve will be too much for the pump to get moving when it starts up, and the pump will burn up or at any rate fail to pump water. I have not had this problem at all with the rulemate pump. Mike ElmoreWindward HullC28 - Hull #7

 

[Richard]

might be a problem

On my old catalina 27 I installed one with no problems. My 30 came with one already and it caused me tons of problems!After much investigation I found that the weight of the water in the bilge line (from one way valve to the outside) was too much for the bilge pump I have. It could not overcome this pressure and open the valve so the pump would pump forever and nothing would happen. After taking out the check valve I have had no problems. I have a rule 2000 pump (farily high capacity for my boat).

 

[hpDon Peterson]

I did it too.

I put one (2000) in this June and have had no problems so far. I read some place, pump capacity's are only 2/3 of rating ?

 

[jv]

The bilge pump topic

If no one minds, I wold like to continue this discussion along more general terms. I am installing bilge pumping system (or "de-watering" system"). How does one determine how much pumping capacity to install? What about check valves? Here's what I'm doing:I have a C-36 that had only the manual pump. I measured 7" of vertical space available, so I bought two of the biggest commonly available pumps that would fit - Rule 2000's (Model 10); plus 2 Rule-a-matic Plus shrouded (enclosed) mercury switches. These pumps will be installed in the bilge at either end of the center bilge access floor board, wired to seperate "ON-OFF-AUTO" switches on the panel, and piped seperately to through-hulls in the transom with a loop of hose as high up inside the hull as practically possible. This will be the emergency pumping system, and therefore won't have check valvels which could impair pumping. A third small (360 GPH) pump with a check valve will be used to dry the bilge. This pump's switch will turn on first. The big guys will not come on unless there's a real problem. Rationale:1. The biggest pump that fits isn't really that much money - I paid about $65. each at West Marine. The 1500's were the same exact size, and about $12. less, and much less power (4.8 Amps versus 8.4 Amps). 2. Two pumps is for "dual redundancy" - if one simply doesn't work, the other is available. I may even route the exhaust hoses along different paths, so that if one is damaged, likely the other won't be.Now, it was explained to me by a colleague that the truth of this is that if you punch a big hole in the boat, no on-board pump will save the boat, you have to plug the hole. However, if you break a through-hull, will a pump save the boat? How many gallons per hour will flow in through a snapped off through hull a couple of feet below the water line? Comments?jvIncidentally, about pump ratings: On the housing of the model 10 is printed: "Pumps 2000 GPH; 12 Volts; 8.4 Amps." However, in the enclosed printe instructions is a table that indicates the capacity for a head of 0', 3.35' and 6.7', for both 12.0V and 13.6V - and the highest capacity is 2000 GPH at 0' and 13.6V. It never pumps 2000 at 12V.