I need to solve a priming problem

[SS MAYFLOAT]

Last spring I installed an aircondioner in my cabin. It works excellent for the most part.<br /><br />Here is where my problem lies. The water intake comes in thru the stern. When I take the boat out and get up to speed, the water going to the circulating pump drains out of the intake line. Then when I get back to the dock and plug in shore power, my pump sucks air and causes the compressor to overheat and kick off on highhead pressure. <br /><br />Usually I remember and always reprime it by taking off the hose coming out of the pump and let the water reprime the intake hose.<br /><br />Last wednesday I took my BIL and family out. They were in a hurry to meet other obligations after the boat ride was over. I forgot to reprime. So when my T-stat called for cooling, it overheated my cabin since there wasn't any water to cool the condenser coils. Saturday I checked on the boat to only find out what I forgot to do The inside cabin temp was 110*F <br /><br />I installed a spring loaded back check valve, but the pump cannot pull enough to pull water through it. <br /><br />Is there a way a making it self priming or a way to bleed the air lock out? It is a royal pain to get access in the bilge to do this each time. <br /><br />I can close the seacock before going out and it won't loose its prime, but again I'm having to access the bilge to do that. Removing stuff on the back deck gets to be a real pain for each time I have to get into the bilge. <br /><br />Any thoughts will be appreaciated. Thanks....SS

 

[prockvoan]

Re: I need to solve a priming problem

Hows about putting in a tee close to the pump,tee off and run a hose up to were you can get to it higher then the pump and put a valve on the end of it.All you would have to do is open the valve,bleed the air out,fire up the pump and close the valve.The pump should be below the water line,by running a tee out hose,up with a valve,that should give you some head pressure after bleeding off the air.

 

[FishyFun]

Re: I need to solve a priming problem

Check for leaks. If water doesn't do what it's supposed to do, it's always air leaks. Tighten, replace all clamps as neccessary.<br /><br />lee

 

[SS MAYFLOAT]

Re: I need to solve a priming problem

Thanks guys!<br /><br />Lee, this pump is below water line. Once the air is bled out of it the water will pour into the bilge. If there was a leak I'd be in trouble <br /><br />prockvoan, you have a good idea. I talked to an engineer for Gorman Rupp. (They make all kinds of industrial pumps). Any hoot, he suggested drill/tap a hole in the impeller housing. Then use a small fitting to run a 1/16" ID line from the impeller housing to a small thru hull fitting. Then when the pump is running and primed, there would be a small stream of water squirting out indicating that the pump is pushing the water or head pressure. Then once I go crusing and lose the prime. The small tube will let the air out thru the hull fitting.<br /><br />So cool, I think the problem is simply solved. I got all the stuff to do it with and its a very cheap fix. <br /><br />Thanks....SS

 

[f_inscreenname]

Re: I need to solve a priming problem

How about a check or one way valve by the transom so the water will not siphon out to start with.

 

[Reel Poor]

Re: I need to solve a priming problem

How about a transom mounted scupper that will hang down just below the bottom of the boat.<br /><br />OR<br /><br />Put a strainer in-line it would serve as a reservoir also.

 

[SS MAYFLOAT]

Re: I need to solve a priming problem

Reel Poor, I've tried two different types of back check valves. Spring loaded and a swing gate style. The spring loaded was too strong and the pump cavatated. The swing gate didn't work because the pump cannot hold head pressure. This pump is a centrifigal type so it won't hold pressure. With the small air bleed line I won't have to remember to do any thing. Sorta automatic.<br /><br />Thanks again....SS