Plumbing Question - Seacock to Head

D

douglee25

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Jan 9, 2008
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29196
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I am trying to determine if I need to replace some suspect plumbing on the waste system from the previous owner.

My question surrounds the water intake seacock to the head itself. It appears (although not confirmed yet) as though Sealand Odorsafe hose or Shields equivalent is plumbed directly from the below water line seacock directly to the head. I am unsure if this is acceptable because the hose may not be rated for direct connection to a seacock.

What is the best way to address this? Purchase the black reinforced hose that is rated for direct seacock connection and then form a loop above the water line. Finally use a union to connect to the current hose to the head?

Thanks again.

Doug
 
I personally would not be concerned, however, if you wait a day or so, I'll bet that those who have been out boating ( or in the case of Vic, our moderator, either sleeping late, or working a convention ), you will get a plethora of other opinions, many of which should authoritatively address your concerns.
 
In most cases the supply water hose that runs between the seacock and the entry to the head is 3/4" I.D.

Shields and Odorsafe hose are used on the discharge side of the head, not the intake side, and they are only available (to my knowledge) in 1 1/2" I.D.

Any good quality reinforced 3/4" I.D. hose should be adequate for the intake side of the head. The clear hose, sold at Home Depot with the nylon reinforcing fibers, as an example, should be fine. Be sure it has the reinforcing fibers in it, don't use the plain clear hose without any reinforcement in it.
 
Thanks for the advice. I have to plumb in a vented loop anyway, so this would be the time to change it.

Doug
 
quote:
Originally posted by Vic Willman

Where are you contemplating adding the vented loop?

Click to expand...


I am adding a vented loop on the raw water intake side. There isn't a vented loop on the whole system and according to ABYC there needs to be one.

Doug
 
That's what I thought you were going to say -- you can't put a vented loop on the intake side, between the through-hull and the entry to the toilet's pump - or the toilet's pump will suck air through the vented loop, and won't draw any water into the toilet. [:-bigeyes2]

The place to put the vented loop is between the output of the toilet's pump and the entry to the toilet bowl. Remove the existing hose and replace it with one that runs up, higher than the top of the toilet bowl. Then mount the vented loop fitting, and run another hose from the exit side of the vented loop fitting, to the fitting at the rear of the toilet bowl. [:-bonc01]
 
quote:
Originally posted by Vic Willman

That's what I thought you were going to say -- you can't put a vented loop on the intake side, between the through-hull and the entry to the toilet's pump - or the toilet's pump will suck air through the vented loop, and won't draw any water into the toilet. [:-bigeyes2]

The place to put the vented loop is between the output of the toilet's pump and the entry to the toilet bowl. Remove the existing hose and replace it with one that runs up, higher than the top of the toilet bowl. Then mount the vented loop fitting, and run another hose from the exit side of the vented loop fitting, to the fitting at the rear of the toilet bowl. [:-bonc01]

Click to expand...


All the diagrams I've referenced mention that you can put the vented loop on the intake. I was under the impression that when the head called for water, the suction caused the vented loop to close so that prime could take place. No?

Doug
 
Vic: I dont think that clear hose is recommended for suction applications.
 
Doug: No. The check valve in the vented loop closes from the pressure of water going through it - emphasis on pressure. On the suction line to a marine toilet, the valve will open from the suction, allowing air to come into the line. If air comes into the line there's no suction, and as a result, no water - or very little water - will come into the head. Try it, you'll see...

Here's an info sheet from Jabsco on vented loops. Jabsco is one of Raritan's biggest competitors, so you won't think I'm biased:

http://www.jabsco.com/files/29015_vented_loops.pdf

pdecat: The clear hose with the nylon reinforcing threads inside it, is fine for a suction line application on a marine toilet. Plain clear hose (Tygon tubing) is a no-no, because it can collapse from the suction from the head's pump.
 
Vic,

I actually have a Jabsco electric 37010 model toilet which your document references. I did reference my manual and it states that you can plumb in a vented loop on the raw water side but efficieny may be reduced (sucking air like you mentioned). They did advise that a solenoid can be installed in the vented loop so that priming can take place when the head is flushed.

I don't think running the vented loop between the pump and the rear of the toilet bowl is possible. The hole that the lines currently run through into the head could be enlarged so that the new lines for the vented loop could pass through. I then could install the vented loop behind the locker. This all seems like a lot of effort though.

I will have to take some measurements to see if the head is even under water based on the water line markings. I guess if it's not, this could be a mute issue.

Any other suggestions?

Doug
 
I hadn't read that far, about adding a solenoid valve in the input line for the 37000 series Jabsco head, I was under the mistaken impression that we were discussing a manual head, and had directed my attention to that. But it does look to be feasable.

However I don't have any personal experience in doing that, and have no idea how reliable the valve would be. I'm going to check with one of my more-experienced servicing dealers, to see if he has any experience with them, and if so, how reliable they are - will let you know what I find out.
 
quote:
Originally posted by Vic Willman

I hadn't read that far, about adding a solenoid valve in the input line for the 37000 series Jabsco head, I was under the mistaken impression that we were discussing a manual head, and had directed my attention to that. But it does look to be feasable.

However I don't have any personal experience in doing that, and have no idea how reliable the valve would be. I'm going to check with one of my more-experienced servicing dealers, to see if he has any experience with them, and if so, how reliable they are - will let you know what I find out.

Click to expand...


Appreciate it Vic.

Doug
 
Doug, called my guy late yesterday afternoon, and he tells me those Jabsco vented loops with the built-in solenoid valve work very well and that he's never had one fail. So there, guess I can't argue with success!
 
quote:
Originally posted by Vic Willman

Doug, called my guy late yesterday afternoon, and he tells me those Jabsco vented loops with the built-in solenoid valve work very well and that he's never had one fail. So there, guess I can't argue with success!

Click to expand...


Good to know. I am going to take some measurements to see if the head is below the waterline or not. If it's not, I may not even need to install one.

Thanks again.

Doug
 
And what exactly happens if there is no vented loop in the discharge side? My toilet discharge hose runs down to a "Y" gate for either the holding tank or overboard.
 
Thanks Capt. Bill. That's what I thought. Just wanted another opinion because just a few months ago I re-did all the sanitary hoses and did not install a vented loop. Yes, the head is well above the water line.
 
For what it's worth; I do not have a vented loop on either the inlet or discharge hose. Toilet above water line & discharge to Lectra-San. Intake is sea water. Has worked just fine for 15 years.
 
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