| Author | Message | ||
| Erston Reisch (Erston)
Registered Member Username: Erston Post Number: 17 Registered: 10-2006 Posted From: 64.40.53.12 Rating: N/A |
Hi again everyone! After a lot of looking and measuring, we're getting ready to order our fresh water and holding tanks... but have realized that we don't know everything we need to know to order, such as what to do about vents, drains and the "input" holes into the tanks. We're looking to order our tanks from Plastic-Mart (http://www.plastic-mart.com), with a 135 gallon fresh water tank and two 95 gallon seperate holding tanks. They're the right height (we have very low bays, 17" max in the center) and will all fit nicely in the rear bay. We're leaving 8" of room between the bus floor and the top of the tanks for plumbing and hope to have everything water related directly above the tanks to simplify the plumbing. We know we need to put vents in the tanks - but we're not sure what to buy, how big the vents should be, where to put them and where to run them to. We would really like to avoid running them to the roof, as we're working hard to return the roof to it's original appearance (ie, not covered with warts). Is that possible? As for drains, how big of a drain for the black water tank? How many inches between the door and the tank should we leave for the dump valve? Where should the dump valve go? What about for the grey water tank? It sounds like a good idea to put a drain in the fresh water tank... and we have no idea where to pick up water from the tank for the pump, so I guess we should ask about that too. Also, Plastic-Mart also has inspection plates in 4-8" sizes, which sounded like a good way to have access to the tank to install the fittings from the inside (or clean it, or whatever). Can you put these on the side and expect them to hold a seal when the tank gets full? As you can tell, we could really use some pointers on what we need to tell the tank people when we order our tanks. Thanks in advance for any advice and suggestions y'all can give, or pointers to places where we can find out more info! ~ Erston and Blue | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 57 Registered: 1-2007 Posted From: 65.61.96.82 Rating: N/A |
If there are no busnuts close I would go look at a RV lot. You will see the basic layouts and valve sizes ect. Both in the RVs and on the parts shelf. I know there is disagreement about having separate black and gray tanks. I have had both setups. I see no advantage to having separate holding tanks. The only time I've had trouble draining a tank was a black only tank. When combined there is enough liquid to keep things flowing. But we tend not to stay parked for extended periods so there is usually plenty of slosh happening. YMMV You have more expense, the need for more room, more fittings to leak and more chance that one tank will be full when the other is not. If you use separate tanks the outlets at least are usually plumbed together at the drains to allow a full gray tank to be added to the black and/or to to use the gray water to flush the black tank. The better setup is to put the gray tank above the black and have it arranged to drain into the opposite side of the black tank to flush it. The one good thing about having a split system is that you can rinse the drain hose with the gray water. We just turn on the fresh water after draining the tank to flush the hose. No matter what I am going to rinse the hose with clean water before it is put away anyway. In a campground hookup, if you are afraid of waste accumulating in the black tank, leave the valve closed until the tank is at least half full and then open the drain valve and the rush tends to move everything better. I don't want to start a debate about it as it has been beaten to death many times. Just want to let you know a single tank is a possibility. Good luck with whatever you do. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 640 Registered: 10-2003 Posted From: 71.58.117.21 Rating: N/A |
A vent through the roof is nice to draw the odors away so you don't smell them in the coach. otherwise they can be a problem when going down the road and open the driver's window. The opening will suck any odor in the coach to the front and past you. Have driven school busses years ago and could tell INSTANTLY if someone lit a match or cigarette or started peeling an orange. They never could figure out how I knew. Some have speculated about drawing the tank fumes into engine air cleaner, or out the bottom. Some on here will tell you what works or doesn't for them in the next few days. | ||
| Michael Sheldon (Msheldon)
Registered Member Username: Msheldon Post Number: 44 Registered: 10-2006 Posted From: 68.230.115.166 Rating: N/A |
One thing I'm considering is "stacking" my waste tanks, with gray above black, with a valve between them so I can flush the gray through the black tank if I choose. | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 442 Registered: 7-2006 Posted From: 66.217.101.161 Rating: N/A |
Everyone should RV for awhile, before starting a bus conversion! There's no need for two waste tanks. Most commercial RV manufacturers plumb the bathroom sink into the toilet holding tank, to insure there will be sufficient water to purge the black tank's waste. Using one tank for both black and grey waste -will- insure there's always plenty of water to totally flush the waste from the tank. It's an option that we can enjoy, rather than conform to the RV manufacturer's whims. Tanks are (probably) least expensive here: http://www.tank-depot.com/ Have fun! | ||
| Jim Wilke (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 156 Registered: 2-2001 Posted From: 69.77.156.44 Rating: N/A |
Our bus has the vent out of the top of the tank, then it goes down & exits under the bus. When we are camped, we DO get odor when sitting outside depending on which way the wind is blowing. AND, despite having installed a 90 degree elbow on the vent, we get exactly the problem John Roan describes. When we are at highway speed & someone flushes, the entire bus is instantly filled with stink! There is NO WAY that I would ever do one like that from scratch and I am trying to figure how to run a vent to the roof. The vent only has to stick up an inch or two which you probably can not see from the ground. You CAN do a pipe & cap but you could just bring the pipe through the roof & leave it open like a house. If it fills a 100 gal tank with rain through a 1 1/2" pipe, you will be floating anyway! Not related, but we have one tank, black & grey combined. Grey water is plumbed to the tank in such a way that it can be sent to the tank or sent directly to the dump connection (after the tank valve) so we can put grey in the tank, on the ground, or down the sewer hose in a campground all while holding the black. This works GREAT. Our 100 gal black/grey will last weeks if used for black only and about 3 days if grey is going to tank while travelling with kids (they like to watch the sink & shower run no matter what you explain to them!) Jim-Bob | ||
| Chris Peters (Chris_85_rts)
Registered Member Username: Chris_85_rts Post Number: 37 Registered: 11-2006 Posted From: 66.194.150.45 Rating: N/A |
I used separate tanks since I bought my tanks surplus, and size wise it worked out better this way. I used the combined valve shown here http://www.pplmotorhomes.com/parts/rv-toilets-tanks/20097.htm number # 23545. So that is a 1.5" grey and 3" black. This is the common size and comes with the fitting you connect the dump hose to and a cap. Once you lay out the tanks, you get 3" and 1.5" connections spin welded to your tanks. As I recall, I used 2" for drains into the tanks and 1.5" for vent, but as I recall, some people use 2" vent also. I did a combined vent for the grey and black. I also used the under cabinet vents. The toilet dumps straight into the tank with a 3" pipe. You can see pics here: http://www.flickr.com/photos/79505093@N00/sets/72157600858590579/ Being an RTS, bay height was an issue, so things are packed in tight. | ||
| Erston Reisch (Erston)
Registered Member Username: Erston Post Number: 18 Registered: 10-2006 Posted From: 70.89.134.94 Rating: N/A |
Thanks for the thoughts and info, all! We looked into a single tank, but our tank choices are really limited by our bay height - the bays on our 4151 are much lower than most coaches (17" is the max height under the center channel), so in order to get enough tank space we had to go with two tanks. We're going to be full timing in our bus, with boondocking for 1-2 weeks at a time... so the option to dump our grey water without harming the place we're camped in appeals. Gotta get back to work, will look into the links y'all posted at lunch - thanks! :-) ~ Erston | ||
| Jack Campbell (Blue_goose)
Registered Member Username: Blue_goose Post Number: 29 Registered: 5-2007 Posted From: 71.101.55.168 Rating: N/A |
Just my thoughts, 135 is sure a large water tank. If you have lots of kids maybe that is ok. I only have a 75 gal tank and we can go 10 days with two people takeing showers every day and the ice maker going. Never have to think about how much water we have. Also 135 gal of water is about 1080 lbs of weight. Jack | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 125 Registered: 12-2000 Posted From: 71.30.252.182 Rating: N/A |
I agree with Jack, 75-80 is plenty of supply for most of us. I do like HUGE waste tanks though as we like state parks which have water hook-ups but not sewer. It means fewer trips to the dump station. I made my own plywood/fiberglass tanks and built a single tank with a divider. It is about 120 gallon total divided 60/40 gray/black. Len (Message edited by lsilva on July 17, 2007) | ||
| Michael Sheldon (Msheldon)
Registered Member Username: Msheldon Post Number: 45 Registered: 10-2006 Posted From: 68.230.115.166 Rating: N/A |
There's no need for two waste tanks. Correction, there's no need for *you* to have two tanks. There are a few of us that occasionally can only dump gray at a given time. Also, given the large amount of volume I need (We often have 4-8 people using the bus facilities for several days) and the fact that we *never* have hookups, I figure it's best that I use multiple tanks regardless. Smaller tanks are structurally stronger, and easier to place around other equipment. My own intent is to use three tanks, one black at 50 gal, and two gray at 60 gal each. | ||
| gary throneberry (Garhawk)
Registered Member Username: Garhawk Post Number: 7 Registered: 3-2007 Posted From: 72.156.222.253 Rating: N/A |
hi erston & blue in our 40 ft rts, we installed one 100 gal combined stainless steel tank. like your bus, the bay height and space is limited. therefore, one tank seemed to be the better plan. one tank - two tanks - looks like an individual decision to me. each method has some advantages and down points. concerning the roof top, we too are trying to maintain an unmolested roof. we vented the waste tank with two 3/4 in. seperately positioned tubes which run up through the walls, then 18 in. across the ceiling into an elbow which extends 1/8 in. through the roof. used fiberglass re-inforced garden hose for piping. easy to make turns and small enough to fit inside walls and ceiling. with two vents, (even tho' they are small) the tank is always breathing. with one vent (no matter the size) the tank is either inhaling or exhaling. gary t'berry rts 102 40er | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1042 Registered: 12-2000 Posted From: 74.12.87.22 Rating: N/A |
Best idea I have heard for next to invisible roof vent is using the drain fitting from the bottom of a sink as your fitting going through the roof. Already equipped to seal the roof, readily available, and connects directly to your regular piping. When the time comes.... happy coaching! buswarrior | ||
| H3-40 (Ace)
Registered Member Username: Ace Post Number: 583 Registered: 10-2004 Posted From: 75.201.154.25 Rating: N/A |
Still don't see the need to have the vent go up, thru the walls and out the roof! Mine goes out of the tank, then down thru the bay floor and then rearward for a short distance! Never an odor problem! Ace | ||
| James Stacy (Jimstacy)
Registered Member Username: Jimstacy Post Number: 71 Registered: 1-2001 Posted From: 75.40.247.94 Rating: N/A |
What are you doing for a refer vent? Tank vents can be brought to the inside of the fridg vent as high as possible. (Please, don't start about methane gas and flame. The warm air is rising through the vent.) Our experience with a down through the floor black tank vent has been no odor while driving but often a smell while sitting outside the coach. Glad I changed it. Our tanks are two 80 gal water, 90 gal grey and 90 gal black. Waste tanks are plumbed together on both sides so black or grey can be dumped on either side, grey can be dumped through black tank for cleaning. Experience after 9 years and 90,000 miles: Freshwater, 160 gal is a lot of water. Two tanks are a good idea as I only draw from one tank at a time and keep other tank shut off for safety. Twice in several years I lost a pressure hose and pumped out one entire tank while we were gone. Second tank looked pretty good then. Sure, I could have left the pump turned off while gone but sometimes it's just easier not to. Could get by with smaller tanks. Rarely fill both tanks past half full now. Waste tanks: 90 gallons is OK for grey water but overkill for black. I plan on changing grey drain to divert some grey water to the black tank when desired. This increases grey capacity and improves black volume for better dumping. Order tanks with extra 3" fittings on the top at each end for cleanouts. You can get a hand and a hose sprayer through a 3" hole if necessary. Most tank suppliers do not charge extra for fittings. Better to have several with plugs screwed in than not have one where you need it. | ||
| H3-40 (Ace)
Registered Member Username: Ace Post Number: 584 Registered: 10-2004 Posted From: 75.201.154.25 Rating: N/A |
That's funny because every time I sit outside my coach, I never smell anything nor does anyone parked beside me! My vent is on the drivers side and have often sat under a canopy on that side in the heat of day into the cool nights with no smell what so ever! Hey whatever works...but I think going thru the roof is asking for potential problems! The less holes in the roof for me, the better I feel about my conversion not having water damage of ANY kind! Ace | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 443 Registered: 7-2006 Posted From: 66.217.102.181 Rating: N/A |
Erston - "the option to dump our grey water without harming the place we're camped in appeals. " We've done our share of RVing, and I've yet to see any place any RVer can dump any amount of waste-water on the ground without being questioned (at the very least). Anyone driving by, or witnessing an RVer dumping water to the ground, is going to be calling some authoritative figure to pay you a visit. And those that don't make a call, will certainly be reciting the scene to his/her pals...... It's as easier for a cop to write a summons, than to argue the point at the side of the road... The court asks: Were you dumping unsanitary waste-water at a non-approved location? | ||
| Bruce Henderson (Oonrahnjay)
Registered Member Username: Oonrahnjay Post Number: 151 Registered: 8-2004 Posted From: 69.143.43.3 Rating: N/A |
John MC9 wrote "We've done our share of RVing, and I've yet to see any place any RVer can dump any amount of waste-water on the ground without being questioned (at the very least)." __. John, I suppose that it's obvious that I agree with this. In the thread that I started a dozen or so lines below, I wrote "I plan to have two grey drain ports, the main one into the black tank for flushing as the black is being drained and one as an "emergency" drain for grey to the outside -- but only to be used to drain into a suitable sewage system. I agree with your feeling about "biohazard" soap and water but decayed food particles (from dishwashing) and body products (mostly biological/bacterial) from washing/showering really should be directed to a proper sewage disposal point." __. Of course, stating that opinion got me disagreed with, but that's about what you'd expect for an internet board. __. I'm going to put in a separate grey dump but only for use at an approved location. I can forsee a situation where "land-based" toilets are about as available as using on board ones so that black tank doesn't fill quickly but the grey one may. Rather than all the work of hooking up the black drain, the cleaning up afterwards, etc., it would be much easier to drain the grey (into a proper sewage drain) and only have to flush out the grey drain hose. __. But it's kinduva moot point for me in that I don't have any space available for a combined tank -- to have capacity for grey and black, I must have two tanks ... and I might as well keep them separate. But I will have the capability to drain some grey into the black, flush the black with grey, and/or drain the grey separately. __. And speaking of the work/cleanliness aspect of draining black tanks, has anyone had experience with the "mascerator/pump out" systems that use a pump and discharge through a small hose? | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 126 Registered: 12-2000 Posted From: 71.30.251.117 Rating: N/A |
"concerning the roof top, we too are trying to maintain an unmolested roof. we vented the waste tank with two 3/4 in. seperately positioned tubes which run up through the walls, then 18 in. across the ceiling into an elbow which extends 1/8 in. through the roof. used fiberglass re-inforced garden hose for piping. easy to make turns and small enough to fit inside walls and ceiling." Gary, I would think that with only those two small vents, you might have a problem with sucking the traps dry when dumping through a 3" hose. The replacement air has to come from someplace. Len | ||
| James Stacy (Jimstacy)
Registered Member Username: Jimstacy Post Number: 72 Registered: 1-2001 Posted From: 75.41.1.43 Rating: N/A |
Bruce, We have been using a macerator for several years with few problems. I set it up as a portable unit with a standard Ventura 3" RV connector for inlet and a "quick connect" for garden hose for outlet. I have a short (about 4') 3" hose I use to connect to the dump valve and a dedicated garden hose (found one in a unusual bright green color). Electrical is a fused line about 6' long with small battery clamps. My start batteries are right next to the water bay so this has been convenient. Do NOT reverse polarity to the pump. It is a permanent magnet field and WILL run backwards. This reverses the rubber inpeller with disasterous results. BTDT. It would be neater to have it permanently plumbed and wired in but I wanted portability. Many others have been thankful it was portable and had standard connectors. I installed an access to the sanitary sewer at both home bases and rarely dump anywhere else. I believe I bought the pump (Jabsco) from West Marine several years ago for just over $100. They come with conections for marine aplications and require a little alteration. As long as you respect the polarity the pump has been trouble free. Fortunately it's a common pump and impellers are readily available. HTH Jim Stacy | ||
| Ron Walker (Prevost82)
Registered Member Username: Prevost82 Post Number: 321 Registered: 11-2003 Posted From: 208.181.210.47 Rating: N/A |
I have one 160 gal septic tank with 1 1/2 in vents that go up then back down through the floor with a running T on the end that creates a venturi when moving. I have 2 vents on the Septic tank one on each end of the tank, so when you go around a corner the water in the tank doesn't create a vacuum and suck all the water out of the P traps. Like Ace I have never had any smell going down the road or parked. Ron | ||
| gary throneberry (Garhawk)
Registered Member Username: Garhawk Post Number: 8 Registered: 3-2007 Posted From: 72.156.222.253 Rating: N/A |
hi len and hello ace first len, there aren't any traps in the vent lines. simply two 3/4 i.d. lines from the waste tank to the atmosphere at the roof top. when one line is exhaling, the other is inhaling and, vice-versa - the tank breathes! when the tank is dumped via the 3" waste gate, the air in the tank is replaced thru the two vent lines! if you are referring to the traps at the kitchen and bathroom sinks, these two 'stoppers' are no more affected than a system with the 'normal' 1 1/2" vent line - no matter where it might exit. secondly ace, for someone who is concerned about holes is the roof, one would assume your coach has some fair sized openings up there. surely those three air conditioners are functional. hope you don't have any leaks. waste venting under the bus may be legal but, you will be hard pressed to convince the average bear that 'stuff doesn't stink'. that 'stinky gas' WILL exit from under the bus and, someone WILL smell it! gary t'berry rts 102 40er | ||
| Jim Wilke (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 157 Registered: 2-2001 Posted From: 64.12.116.203 Rating: N/A |
The reason sewer vents go up through the roof in a building is because sewer gasses are lighter than air & rise. If the pipe goes down near the road, the tank has to remain full of lighter than air gasses. You guys can build yours any way you want. But I am venting mine through the roof having lived with it the other way. Jim-Bob | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 127 Registered: 12-2000 Posted From: 71.30.251.117 Rating: N/A |
Gary, My point had more to do with size of your vents. Two 3/4" lines is a total of 0.88 sq inches and the three inch drain is about 7 sq inches. It seems to me that that will set up quite a vacuum in the tank when draining it and that's what might empty the sink traps. It might also cause the tank to drain slowly. A 1-1/2 vent is twice as big as two 3/4" vents. If you ever go to a rally where they have a honey wagon to suck out your tanks, even the 1-1/2" might not be enough. I like the idea of using two vents, just think they should be larger, but if it's working for you then that's all that matters. Len | ||
| H3-40 (Ace)
Registered Member Username: Ace Post Number: 585 Registered: 10-2004 Posted From: 70.220.14.141 Rating: N/A |
Gary you assume right! I DO have 3 roof airs and yes they are functional but if you read my post, you would see that I said the "LESS" holes. I never said anything to the fact of "NO" holes! I just can't see adding a hole to let gases out when in fact you can do it by going downward and rearward such as I have! You say that stuff stinks and I agree but I have YET to smell anything from mine sitting still or traveling! I guess my shit just don't stink!  Ace | ||
| JJ Woden (Jj_woden)
Registered Member Username: Jj_woden Post Number: 29 Registered: 10-2006 Posted From: 71.210.42.121 Rating: N/A |
Me thinks you can get a larger volume of air thru .88 sq in than volume of water/solids thru 7 sq in. Especially by gravity flow. No calculations, just speculation. JJ | ||
| gary throneberry (Garhawk)
Registered Member Username: Garhawk Post Number: 9 Registered: 3-2007 Posted From: 72.156.222.253 Rating: N/A |
hi len thanks for the calculations. point well taken. however, will be pumping waste tank thru macerator and garden hose. although the first exit from the waste tank is 3", the macerator is plumbed to the 1 1/2" gate and reduced further to the 3/4" hose. should be enough exchange air thru two 3/4" vent lines. if and when the tank is dumped through the 3" gate, you may be correct in that it could suck dry the sink traps. if that proves to be the case then, we'll just place the rubber stopper in the sink drains when we dump thru the 3" gate. won't that work? gary t'berry rts 102 40er | ||
| gary throneberry (Garhawk)
Registered Member Username: Garhawk Post Number: 10 Registered: 3-2007 Posted From: 72.156.222.253 Rating: N/A |
hey ace, glad to hear your 'stuff' doesn't stink. was worried about getting parked next to you sometime. now that fear has subsided. gary t'berry rts 102 40er |