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cal40john · 08-02-2007, 22:16

I went with schedule 40 PVC. Where the pipe passes through bulkheads I have wrapped foam around it. I have a short length of hose at each end so that the pipe is de-coupled from the rigidly attached to the boat pieces. The hoses are in accessable areas, and where possible angled to drain back into the tank so nothing remains in the hose. The 10" piece from the head to the PVC is the exception for drainage. Everyone that has written on the topic agrees PVC will never have an odor. There is disagreement on suitability of use on a boat though. Some say, Peggy Hall for one, that say PVC will eventually fail due to vibration. So I have followed the directions of those who say it can work. My install has only been in service for 3 years and no problems so far, well as far as the pipe is concerned.

I had all my ports in the tank installed on top. The local MSD shop sells a pickup tube that consists of an angled rubber gasket that you shove a PVC part through that has the pickup tube. The part squeezes the rubber against the hole that you drilled in the tank and seals everything. Dealer says it will never leak. It has worked perfectly except for the time I was sure that the tank was not full and even though I felt back pressure on the head's pump I kept pumping. Well the tank was indeed full and the two vent lines filled and I was pressurizing the tank faster than the vent lines could deal with it once they had liquid in them. The seal did work well enough that there couldn't have been more than a ml or two of a leak and it all just sat on top of the tank for an easy clean up.

08-02-2007, 22:16	#6
cal40john Registered User Join Date: Dec 2006 Location: Seattle Boat: Cal 40 Posts: 593	I went with schedule 40 PVC. Where the pipe passes through bulkheads I have wrapped foam around it. I have a short length of hose at each end so that the pipe is de-coupled from the rigidly attached to the boat pieces. The hoses are in accessable areas, and where possible angled to drain back into the tank so nothing remains in the hose. The 10" piece from the head to the PVC is the exception for drainage. Everyone that has written on the topic agrees PVC will never have an odor. There is disagreement on suitability of use on a boat though. Some say, Peggy Hall for one, that say PVC will eventually fail due to vibration. So I have followed the directions of those who say it can work. My install has only been in service for 3 years and no problems so far, well as far as the pipe is concerned. I had all my ports in the tank installed on top. The local MSD shop sells a pickup tube that consists of an angled rubber gasket that you shove a PVC part through that has the pickup tube. The part squeezes the rubber against the hole that you drilled in the tank and seals everything. Dealer says it will never leak. It has worked perfectly except for the time I was sure that the tank was not full and even though I felt back pressure on the head's pump I kept pumping. Well the tank was indeed full and the two vent lines filled and I was pressurizing the tank faster than the vent lines could deal with it once they had liquid in them. The seal did work well enough that there couldn't have been more than a ml or two of a leak and it all just sat on top of the tank for an easy clean up.