electra-scan plumbing questions

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ybrad

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Mar 3, 2009
54
Hunter 37-cutter Rockledge, Florida
Have just read through the Head Mistress’ forum for MSD threads and now know a whole lot more than when I started! Recently I purchased an electra-scan and a PHII for our Hunter 37C project. (it’s the 3rd Raritan MSD that I’ve owned dating back to the 90’s).
Here are a few questions for Peggy or anyone else that wants to input.

If a holding tank will also be incorporated (for FL Keys cruising in the future), is it still your current thinking to install the diverter valve after the head discharge and prior to either the e/s or holding tank(i.e. select discharge into either the e/s or holding tank)?

Do I understand that it is acceptable to have 2 discharge hoses utilizing a single thru-hull? (I.e. the holding tank discharge hose is ‘T’d’ into the e/s discharge hose prior to the T/H.) If so, what about a ‘Y’ adapter instead of a ‘T’ (to avoid the 90° turn)?

Would the above ‘joint use” discharge configuration require a vented loop on both the e/s and holding tank discharge hoses? (assuming they are BWL installations)

In the e/s manual, I don’t see Raritan mention the 6’ discharge line requirement. Is the idea here that if the discharge line is too long, effluent may not be discharged in a timely enough manner to prevent (surviving) bacteria from regenerating? As planned, I’d have about a 9’ run from e/s to T/H and that doesn’t include ‘rise’ for a vented loop (add another 4’-5’).

As mostly 'weekend' cruisers, would multiple treatment cycles at the end of an outing mitigate this problem?

Thanks for advice, some things are best to figure ouit before the first real flush!
 
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Oct 22, 2008
3,502
- Telstar 28 Buzzards Bay
1) Don't use T-shaped joins in a head system. Use only Y-shaped ones. The T-shaped ones are far more likely to clog.

2) If you have two discharge lines using a single through-hull, you really want to have a diverter valve installed. This prevents the discharge of one from backing up into the other, which could happen if the seacock were closed.

3) If you have the high-loop portion after the discharge line diverter valve, you can get away with having just a single anti-siphon device in the discharge line for both devices.

IMHO, you should have the following

Head discharge leads to diverter valve #1: 1) to ES; 2) to HT

ES output leads to diverter valve #3 that leads to macerator pump/manual diaphragm pump and then to seacock and through hull.

HT output leads to diverter valve #2 that leads to: 1) deck pumpout fitting; 2) diverter valve #3 and then to macerator pump/manual diaphragm pump and then to seacock and through hull.

This allows you to dump the ES overboard, dump the HT overboard when out past the THREE mile limit, or have the HT pumped out at a pumpout dock/boat.

Make sure that all valves are easily accessible and clearly marked. If you don't have the right valves in the right positions, you're going to pressurize a hose and that can lead to some really unpleasant consequences.
 
Dec 2, 1997
8,948
- - LIttle Rock
Electra Scan plumbing

If a holding tank will also be incorporated (for FL Keys cruising in the future), is it still your current thinking to install the diverter valve after the head discharge and prior to either the e/s or holding tank(i.e. select discharge into either the e/s or holding tank)?
It really doesn't matter whether the waste goes into the tank treated or untreated...'cuz if even ONE li'l ol' bacterium survives treatment, within a very short time, especially in hot weather, it's gonna multiply into zillions in the tank. So put the y-valve where it's most easily accessed.

Do I understand that it is acceptable to have 2 discharge hoses utilizing a single thru-hull? (I.e. the holding tank discharge hose is ‘T’d’ into the e/s discharge hose prior to the T/H.) If so, what about a ‘Y’ adapter instead of a ‘T’ (to avoid the 90° turn)?

You understand correctly...that is acceptable. And it doesn't matter whether the fitting is a tee or a wye...although I prefer a y-valve instead of either one.

Would the above ‘joint use” discharge configuration require a vented loop on both the e/s and holding tank discharge hoses? (assuming they are BWL installations)
You can get by with one vented loop if you put it AFTER the connection.

In the e/s manual, I don’t see Raritan mention the 6’ discharge line requirement. Is the idea here that if the discharge line is too long, effluent may not be discharged in a timely enough manner to prevent (surviving) bacteria from regenerating? As planned, I’d have about a 9’ run from e/s to T/H and that doesn’t include ‘rise’ for a vented loop (add another 4’-5’).
6 feet is about as far as bowl contents will travel in the length of time that 99% of people will spend pumping a manual toilet or leave their finger on a flush button...which is why Raritan specifies that the treatment devices should be within 6' of toilet...the flush can't be treated if it doesn't make it into the device. However, gravity can make a difference...and when the device has to be further that 6' away, a loop--not necessarily vented--immediately after the toilet that creates a downhill trip all the way from the top of it to the device can solve the problem.

And btw...the tank should also be within 6' of the toilet--or plumbed to create assistance from gravity--to avoid leaving waste sitting in the head discharge line to permeate it.

As mostly 'weekend' cruisers, would multiple treatment cycles at the end of an outing mitigate this problem?
No...'cuz multiple treatment cycles won't move any waste that hasn't made it into the device, it'll just treat the bejabbers out of what's already in it. So I think we may need to rethink your planned installation. Give me a shout via email if you'd like some help with it.
 

ybrad

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Mar 3, 2009
54
Hunter 37-cutter Rockledge, Florida
SD-

Wow...that is quite a manifold that you describe...an advanced system offering many control options. Under my KISS program I will most likely be surrendering some functionality for, well, keping it simple. It could be years before I need the holding tank, so it is a low priority. Thanks for the description; maybe way in the future it will happen.
 

ybrad

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Mar 3, 2009
54
Hunter 37-cutter Rockledge, Florida
Thanks so much for the reply Peggy. I may have to shift gears to direct contact soon, but let me run with this a little more in the form; it's a good education for those reading up on this stuff.

It really doesn't matter whether the waste goes into the tank treated or untreated...'cuz if even ONE li'l ol' bacterium survives treatment, within a very short time, especially in hot weather, it's gonna multiply into zillions in the tank. So put the y-valve where it's most easily accessed..
That 'regeneration' concept is one of the largest learning points that I had from reading through the posts. Acknowledging that consideration, if the diverter is installed after the e/s, the only relevant down side is extra cycles on the e/s when the discharge is directed into the tank. (As opposed to directing the discharge to the tank prior to the e/s.) Is this correct?

You understand correctly...that is acceptable. And it doesn't matter whether the fitting is a tee or a wye...although I prefer a y-valve instead of either one..
Great, thats good news.

You can get by with one vented loop if you put it AFTER the connection..
More great, glad I asked. Double vented discharge loops wasn't seeming desirable.

6 feet is about as far as bowl contents will travel in the length of time that 99% of people will spend pumping a manual toilet or leave their finger on a flush button...which is why Raritan specifies that the treatment devices should be within 6' of toilet...the flush can't be treated if it doesn't make it into the device. However, gravity can make a difference...and when the device has to be further that 6' away, a loop--not necessarily vented--immediately after the toilet that creates a downhill trip all the way from the top of it to the device can solve the problem..
Great answer but a bad question; at least not a clear one. However, the non-vented loop was an area of interest for me, but I didn't know enough to pose a question.
What I really meant to say in the original was 'Raritan doesn't mention the 6' requirement for discharge from the treatment tank.'
My planned installation has the e/s within 6' of the PHII, but the T/H is about 9' from the e/s. With that in mind, would you please readdress this question?

I've ordered your book and look forward to getting to read it.
Also, I've figured out how to use 'quotes' somewhat and cleaned up the original reply from this morning (if you saw that mess).

Thanks again,

Brad
 
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