The keel boat thread brings up a question.
Are back flow preventers safe for the bilge pump.....the shower pump.
Seems like on the shower it should be no problem but on the bilge, if there is a chance of failure, as in "freeze in the closed position" it would be a bad thing.
I suppose it would be possable to have a secondary pump with a lower suction port, use a back flow preventer and connect it's outflow past the "hump" on the exit hose. It would, of coourse, need it's own hump above the water line. nLooks like the Whale pump mentioned in the keel bolt thread would pump much dryer particularly if it had a back flow preventer. If the original pump was left in place as a back up, this seems like a safe installation.
Has anyone tried this or anything like it?
Neil Roach
"Crewless"
1992 36, Mark I
Hull # 1174
Seattle
Neil,
Yes, it has been done before. This was the first "hit" when I did a search for "bilge pump" on the website. There's TONS of info already on the site.
[URL]http://www.c36ia.com/node/944[/URL]
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
BFs would be in different places in the shower usmp compared to the bilge pump.
The shower sump has a check valve between the sump and the diaphragm pump. It prevents seawater from backfilling the sump when the pump stops, as well as stopping the water in the line to the pump from backing into the sump. The check valve is a necessity for this system. Many of us have placed small screening material over the floor inlet to keep smaller pieces from even getting into the sump.
For the bilge pump, the pump comes first, then a check valve, then the hose to the above water thru hull. If you have two pumps, you need two check valves.
Check valves are not recommended for bilge pump systems because they can get clogged. If you want two pumps, run another hose to a new second thru hull outlet.
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
Stu. Of course the bilge and the shower are two different cases. On my boat the shower is drained be a Rule bilge pump, with no BFP. From what you describe, it sounds like I could install a preventer with no problem.
As I described in my thread, I am contemplating installing a second pump, with a lower pick up. On this second pump I would install a BFP. I would leave the original system as is, with no BFP. The new pump would be plumbed separately only joining the outflow through a "Y" on the down hill side of the of the outflow.
The net result is: one pump, with a BFP, pumps the bilge under normal circumstances and gets more water out because of it's very low inlet, Whale pumps are advertised to do this. Should this pump become clogged or fail or should the BFP fail, then the original system operates just as it does now with no BFP.
Comments?
Neil Roach
"Crewless"
1992 36, Mark I
Hull # 1174
Seattle
Tom, I wish the web site worked for me the way it seems to work for you. When I follow your suggested link I get advertising and a new log in page. After logging in on the new page I am taken out of the web site. When I search bilge pump on the site, as you did, the first thing up is my thread.
For my part, I often ask a question because the search function often doesn't work, sometimes asking for 4 word searches though clearly not really needing one. It often also just takes you to a new log in page.
In it's defense, it often works very well.
I know the old hands get tired of replying to questions which may have been covered in other threads or articles but sometimes the info is not all so easy to find or the topic has not been covered in the same way.
Neil Roach
"Crewless"
1992 36, Mark I
Hull # 1174
Seattle
Neil,
I should have explained more clearly. The search I did was in the main part of the website, and not in the forums. I know that many people don't even know that the C36/375IA website exists (they just go straight to the forums), but the main site contains LOTS/TONS/HUGE amounts of info. If you computer "remembers" your login info, you should be able to go seamlessly between the two (website and forums). If you see lots of ads, that means you are not logged in. When you do a search in the main part of the website, you are searching the pages that include all the technical, maintenance, and upgrade articles. As I helped put the articles on the site, I know from first hand experience that there are hundreds of them!!! The forums started from scratch a few years ago, while the main part of the website was initially fed from two previous sites, going back more than 10 years. There are a lot more 'how-to' and detailed articles on the website compared to the forums. You should check it out. Hope this helps.
PS-One other thing I should mention. If you get very few 'hits', or you navigate to a page on the website that says "There are currently no posts in this category", it means you are not a member of C36/375IA, and don't have access to the Technical Section. Membership has its privileges!
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT