Elegant Lady Plumbing
While replacing a failed macerator pump this week I ended up taking apart all the copper piping in the waste water bay to provide easy access to the macerator pump (and to polish the piping to make plastic piping owners envious).
While this post is the perfect opportunity for those not having a coach with such spectacular appearing plumbing to poke fun at us, let this be considered a word of caution for those that do have the pretty polished copper piping.
About 3 or 4 years ago the piping that goes from the top right fitting into the top of the tank at the right (Not shown in the photos) was replaced on my coach. I had just gotten through polishing my slack adjusters and was working on the copper and I noticed the pipe had perforated due to some corrosion that began inside the pipe.
Now the pipe I made to replace the original is showing signs of internal corrosion and its life is limited.
The piping assembly that extends from the center top of the compartment, and two fittings on the tank to the gray water by-pass valve is also showing signs of significant corrosion and in spots of the assembly it is paper thin. It also had extensive internal build up of a black material that would break off in hard chunks. The life of this tubing assembly is also limited.
The centrally located tube which extends from the bottom of the holding tank to the macerator inlet is sound and free of evidence of corrosion. The tube which extends from the top LH fitting to the top of the tank on the left is also free of build up or corrosion.
The photos show the blue corrosion on one of the tubes which indicates the copper is being eaten away. We do not use chemicals other than soap or dishwashing soap so I have no idea what would be causing the corrosion. I chipped some of the black scale from the pipe interior so it is not possible to see how occluded the pipe had become despite being relatively new.
On the photo of the piping the assembly, the left hand side tubing assembly is the second one I consider life limited. The upper portion of this assembly under the clamp at the rubber connector already had perforated completely through, but because of its location I can get more use out of it. It will not be long before I have to remake that assembly.
The last photo shows a 3/4" stub sticking out to the right of the tubing leading to the gray water by-pass. I am revising the macerator discharge so it is introduced to the waste line at that point. As it has been plumbed it exits at the top of the bay and makes a convoluted path to the hose bib at the rear of the bus. It will now share the hose bib with the gray water by-pass. I will post pictures when I am done. I did this to significantly reduce back pressure on the pump by shortening the discharge piping.
My reason for posting this is to alert those with this type of waste water piping to be alert to potential tubing perforations, with the result possibly being a leak of waste water into the bay. Sometimes plastic is good. It is just not as pretty.
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Originally Posted by Kenneth Brewer
Gary & Lise Deinhard, 2003 Elegant Lady Liberty, Dbl slide