1 1/4" thru hull enough for 3 simer pumps?

(jwat142) · (jwat142) **Join Date: Jan 2002** 01-03-2005, 11:47 AM

I'm putting in a thru hull scooper that will feed 3 simer pumps. I was wondering if a 1 1/4" thru hull would be big enough to supply all three pumps if they were all running at the same time or should I go with a 1 1/2" thru hull?

(jwat142) · (jwat142) **Join Date: Jan 2002** 01-03-2005, 11:50 AM

If it helps, I believe the threads on the simer pumps are 3/4" which would make the actual inlet and outlet ports 5/8".

(mikeski) · (mikeski) **Join Date: Aug 2003** 01-03-2005, 12:35 PM

Just using simple math the 1.25 provides almost the same area as three 0.75 hoses, more than three 0.625 hoses. The 1.25 will flow plenty, 1" might be enough. I would not use a scoop, use a simple thru hull so they will fill and empty at the same rate.

I sold my boat with the Simer pumps, my next system will be aerator based to cut down the noise. After having spent a summer with the Simers I think aerators work better for ballast pumps, they just take a little more engineering to get them to work correctly.
water loop diagram

(jwat142) · (jwat142) **Join Date: Jan 2002** 01-03-2005, 12:40 PM

So, you would suggest using just a regular mushroom type thru hull? I asked another question about what type of thru hull to use in another thread and there were differing opinions. Do you think the simers would have any problem priming even if they were a couple feet away from the water source? Thanks for the info.

(cyclonecj) · (cyclonecj) **Join Date: Jul 2001** 01-03-2005, 4:16 PM

No, they are self priming, they'll have no problem. Aerators work fine that way too as long as they are below the waterline and oriented correctly (inlet on bottom) Mushroom fitting has worked fine for me for three years.

(jwat142) · (jwat142) **Join Date: Jan 2002** 01-03-2005, 6:25 PM

Oh yeah, one other question for those who use a regular mushroom type thru-hull. Do you use anything as a strainer to keep debris from getting sucked up the hole? That's another reason I was looking at the scoop type because it would filter out any large debris that would get sucked up there otherwise. Is there anything you can buy that would filter out debris for the mushroom fittings that won't restrict the water flow at all?

(cyclonecj) · (cyclonecj) **Join Date: Jul 2001** 01-03-2005, 8:10 PM

I don't but sure, you could put a sea strainer on it if you wanted to. Here's an example off ebay
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4516688213&catego ry=26455&sspagename=WDVW