SeanF said:
... One campground I've been to required the use of a rubber "doughnut" to ensure a seal between their dump and your hose. They probably won't care if it's only graywater...
MANY campgrounds require either a grey or black "sewer donut"
or the two piece "elbow" set up
either way it's to prevent the smells from the open sewer drain from smelling up the campground. (currently running the two piece one shown in the pic... Class C is using the red one shown above)
Many campgrounds do not allow a sewer hose to sit on the ground for various reasons. Some places, it's against the law. Other places it's aesthetics or to prevent the hose from being damaged by grounds crews. Either way, you want a good slope from your waste valve to the campground's sewer pipe. We use a PVC rain gutter (the type you put on houses). Currently we are running a standard 3" RV sewer hose (attached to our PVC elbow with a hose clamp.... we put a PVC ball valve in, not an RV blade type gate valve and no bayonet termination fittings for sewer hoses). It fits nicely into a rain gutter. DO NOT BUY THE PLASTIC STINKY SLINKY! I dislike both the metal & plastic ones but the plastic one is garbage. Too cheap to buy the metal one? Then go buy a $6 length of PVC rain gutter, cut it down (one section will slide into another) and suspend the bus end with a chain or bungie cords from the bottom of your bus. Bungie cord the other end tight to the sewer elbow. You do was to slope your sewer hose for good drainage. The less you move your sewer hose, the less likely you will put a crack in the vinyl.
TIP: EU6000 (available in the craft section or glues section at WalMart) is a good glue for glue a crack or pin hole in a sewer hose. Apply a liberal "glop" over the "hole" Do not dump until the glue has dried... either all day or over night. A patch of this type had held on the Class C's heavy duty sewer hose for two years now (not been moved and well supported with a rain gutter support). This is a two piece run and both sections will be trashed when Stacey leaves. The fittings will be saved to be used on another hose.
TIp: if using the 3" hose.... Get the "heavy duty" hose KIT first from walmart. Save the fittings. I like the red ones. Upgrade the hose later if you want. The heavy duty ones last about 1 year even with moving a lot. Birds & other critters like to poke holes in them so you may want to keep an extra one (rotate out every year). Sun rots them all. Don't go lighter than "heavy duty". DO NOT get "standard duty" hoses as they are a waste of $$. Very handy if you also keep a straight coupler on hand to attach the two hoses together (had to do that twice in recent years... Class C is sitting with 15 ft sewer run right now using two 10 ft sewer hoses). 10 ft sections should be what you need. You will most likely find that 10 ft is more than enough.
I like the disposable nitrile gloves I buy from Sam's Club. I use them also for packaging up food. When I need to dump, I pull a few out of the package I keep in the kitchen. Lots of uses for disposable gloves. They are cheap, go bad ("rot") in a few months, so use lots.
That said... we are going to be hooking a macerater directly to our black tank. We will pump thru a 2" flexible "spa" type hose from bus to sewer drain pipe. It is a ribbed, heavy duty hose that is semi-smooth on the inside. We will build a slip in connection, similar to the stepped elbow fitting, out of PVC pipe/fittings to allow us to slip the 2" hose into the campground sewer pipe and seal against smells. Before you decide to follow similar suite, I suggest you visit several campgrounds and measure their sewer pipes. NORMALLY we have found 3" PVC pipe is typical. Have only run into one that was larger.... I darn near lost my grey sewer donut into the pipe... had to use both the sewer donut on the "stepped" sewer fitting to seal the fitting to the pipe. We have limited space to store a sewer hose & fittings. I dislike the 3" RV sewer hoses. I invariably put one up with no holes and take it out with holes.
I suggest you read...
How To Dump your Tanks