New Head, Old Boat

[John Miller]

PeggyThanks for all your time and energy. I am looking forward to reading your new book in the spring.I read over 800 entries in the archives that are retrieved with "vent loop" as the search. A lot of good information, although it is easy to see that you have a number of cut and paste answers for folks who keep asking the same questions over and over.Having said that I hope my questions are not too much of a repeat.I have an 85 Hunter 34 with a head and hoses that are probably the original equipment, if they are not original they certainly very old. I am planning a complete refit this winter using your recommendations. Attached is a drawing of the major components, including head, three vented loops, top of holding tank fittings and diaphragm pump for off shore use.Several times you recommended 5" clearance for the top of the tank mounted fittings. Is this clearance for the bending radius of the SeaLand Odorsafe hose. Is there any reason not to use 90 degree PVC fittings in this area to reduce the amount of headroom required above the tank. I have not measured the V-berth for a tank but I know there are several that should fit in the Raritan Catalog.For a bow-mounted tank you have recommended two vent lines going to the port and starboard sides near the bow. What are your recommendations for the top of the tank fittings? Both to the centerline or the starboard vent to the port side of the tank and the port vent to the starboard side of the tank.Do you know if immobilizing the diaphragm pump handle with a plastic cable tie will meet Coast Guard requirements for preventing overboard discharge?Don Casey stated in "This Old Boat", that a head should never be mounted side-to-side but always with the bowl in a fore and aft direction. The head in my H34 is mounted with the bowl oriented in a side-to-side direction. I have not measured to see if a PH-II will fit fore and aft in this space but I would like your feedback before I seriously consider this orientation.I also plan to add a deck wash down pump. Is there any reason I should not add a T after the head inlet strainer and connect a wash down pump to that T? Will your book be in the Chandlery and do you have a better date than Spring 03.Thanks in advance for your help.

 

[Peggie Hall/Head Mistress]

Your diagram looks fine

Just remember that the vented loop in the head intake must go between the pump and the bowl...it cannot go between the thru-hull and the pump. 5" clearance is required for fittings on top the tank because a 1.5" thread-barb elbow tank fitting is 4.5" high when threaded into the tank. Don't even THINK of trying to bend a hose 180 degrees. It cannot be done without risking a kink in the hose. For the same reason, do not heat the hose to bend it tighter than it wants to bend easily anywhere in the system. Heating hose to bend it weakens it, which can lead to a collapse. If you have to make a tight bend, break the hose and insert a radius fitting.Your best source for the tank is Ronco Plastics (they supply most of Raritan's tanks). See link below.A single 1" vent line less than 5" long that's straight and doesn't rise more than 45 degrees should ventilate your tank sufficiently. Come off the bow end of the tank, out the hull about a foot below the toe line. If the vents are vertical, two won't do any more good than one. Securing only the pump handle may not be enough to satisfy the CG unless the seacock handle is also secured. A cable tie is adequate.There's no reason I can think of why a head cannot be mounted port/starboard OR fore/aft.As long as no one flushes the toilet while the washdown pump is use, there's no reaons why they can't share the same intake thru-hull. I suggest you use a y-valve instead of only a tee fitting. If the toilet is used, drawing water away from the washdown pump, it can cause excessive wear of the impeller in the washdown pump.You'll have to ask my publisher for a more specific date than early spring for the release of my book. I've done my part...the rest is up them. Phil and Bly have said it will be available in the chandlery.I have never cut/pasted replies to posts. However, you may have found archived articles from the Head Mistress forum library.

 

[Vic Willman]

Hose Runs

A little trick I've found for large radius elbows in sanitation lines is to get a nominal 1 1/4" "sweep elbow" in gray PVC at Home Depot-type places, not in the plumbing department - but in the ELECTRICAL department. They have "sweep elbows" available in gray PVC to use for electrical conduit THAT'S glued together with PVC cement. If the elbows have a swaged area at each end so that a pipe can slide in and be glued, cut the swaged ends off with a hacksaw. If not, just slide the hose over the end of the elbow and clamp it well - you've now got your wide radius elbow. They're relatively cheap, too !!