Installing a new water tank and all new plumbing (1973 Brave D18)

[perlgurl]

I’m replacing the water tank and all the plumbing in my RV because it’s either old tubing or copper and I live in a place where it gets to be -40F in the winter so I want to use PEX since it will flex better in the cold winter (yes, I know to drain everything and put in winterizing fluids).

Anyway, I need some help understanding how to do this:
I’ve got my new 42 gallon water tank, a sureflow pump and a new intake valve.  I know I need to buy  bunch of PEX and some “shark” fitting/connector things.  What I’m not clear on is how to actually get water in an out of the tank since there seems to be four places on one end only for tubing (one red and three blue), whereas the old steel tank had three holes in it; one at one end for putting water in, one at the other end to push water through the system and another (from the side near the intake end) for draining.  Am I correct in assuming that the red is my in (or out) and then I am supposed to use one of the blue to the other?  It looks like there are plastic nuts that maybe screw off the blue holes?
Photos below include old intake valve, old tank, new tank (still to be fully installed) and end of new tank with what I think are the input and output holes. 

[perlgurl]

Also I’m thinking about getting this for showering.  My shower space is not ready for showering yet, but this can be used outdoors and then once I get a pan liner for the shower I can install it in the coach.  What do you think?

http://www.amazon.com/Eccotemp-L5-Portable-Tankless-Outdoor/dp/B000TXOJQ4?ie=UTF8&psc=1&redirect=true&ref_=ox_sc_act_title_2&smid=ATVPDKIKX0DER

[Rickf1985]

Well if I were to guess I would say that the red fitting should be at the top and is your fill since it is the largest fitting. The one on the other side on top will be the vent line that will go to the same place as the fill tube on the outside of the RV. The two bottom fittings will be for supply lines, you will use the one that is most convenient to access your new electric pump.  You DID install the tank with the red fitting up didn't you?

On the heater I don't see any problems as long as the pump will maintain more than 20 lbs. of pressure. I would say it should hold at least 35 lbs. to be on the safe side. The flow rate should be good for most of the pumps out there.

[perlgurl]

Ah! This makes sense! I have not installed the tank yet, partially because it is larger than the original so I need to do some wood work to make the couch deeper in order to accommodate it and partially because I didn't know if the end with the holes should go closer to the intake (near the front of the RV) or closer to the sink (towards the middle back). 

This is the big project for this coming weekend!

[Froggy1936]

As you do not show what you have or plan on using for a fill on the outside I recommend Getting a new style Fill and vent assy  Mount it as close to above the  Red hole in the new tank ( remove and cover hole for original with a aluminum plate pop riveted on ) Plumb The fill pipe with plastic House pipe  of the same size as fill fixture and red inlet on the tank W radiator bulk hose cut to length and hose clamps. The blue hole will be hooked to the vent on the new fill fixture w rubber hose, (make sure there are no level or low spots (will freeze) in vent hose It will self drain The other two fittings on the bottom one  will go to the ground through a easily available drain valve , The other to the pump inlet Locate the pump any where that is easily accessable . Additional drain valves @ low water lines to the ground will make complete draining possible Along with a low air pressure 20 to30 lbs fitting for the fill connection (pinching off the vent hose ) All lines can be blown out incl the hot water tank After  draining! Don't forget to anti freeze all traps @ sinks & shower after blowing all water out of lines use enough to protect any small amt left in black and grey tanks !( this method does not require anti freeze in the useable water lines or flushing lines when refilling) Wire the pump thru a on /off switch W a indicator light Switch near the sink or door ! Turning off  pump wile  traveling eliminates a flood from any developed leaks wile moveing   Good Luck  Frank

[perlgurl]

This is the new intake vale I got to replace the old one:

[Froggy1936]

I did not see  this post before I made mine . I cannot tell if there is a vent hose connection on there  If not you will need one that has both ! Preforably with large fill pipe not Garden hose diameter Also I did not include a semi permanent water hookup !!Frank

[perlgurl]

I posted the photo after you made the longer post above

I think you are answering my question.  My new intake does not have a vent on it, whereas my original one has a vent (tiny silver pipe on the left side of the original intake photo).  Even though I am changing from a pressurized system to a using a pump, I still need a way for air to come out of the tank as water goes in since it would otherwise be a closed system with no way for water to get in where there was air, right?

[joanfenn]

That looks like it is the city water hookup to me

[perlgurl]

Hum. Maybe I don't understand how to get water into the tank. 

My new intake thing is not my water tank fill valve?  On my RV right now there is only one way to get water into the tank, through the old (first photo).  That is what I am looking to replace since my is cracked and really hard to use. 

[perlgurl]

I get it now!! At least with regard to the "Fill and vent assy" 

I'm so glad to have you all to bounce ideas off and and get feedback!

This kind of thing is what I need.  I just need to find something like this that will fit my WICKED OLD RV.

[joanfenn]

like this? http://www.dyersonline.com/jr-polar-white-low-profile-gravity-water-hatch.html#

[M & J]

Fenn and Frank are quick for elderly folks. But yeah, you brought a city water connection.

[joanfenn]

and you're just jealous

[Froggy1936]

Yep thats the one. The one you already purchased you can also use if you want a semi permanent connection also (I very seldom ever use mine I just keep filling my tank as necc)  It would connect to the outlet pipe of the pump anywhere convenient !  Frank

[Rickf1985]

And be sure the gravity fill you get has a vent connection also or you will have to make another hole for that.

[DaveVA78Chieftain]

Might be best to start with a standard diagram so you can see all the components and how they hook together.

The gravity Fresh Water Fill is used to fill the tank.  It is the supply for the Water Pump
The city water inlet is on the output side of the water pump because that water, from say your house via a garden house is already pressurized so the pump is not needed.

[M & J]

Super Dave strikes again.

[perlgurl]

Might be best to start with a standard diagram so you can see all the components and how they hook together.

The gravity Fresh Water Fill is used to fill the tank.  It is the supply for the Water Pump
The city water inlet is on the output side of the water pump because that water, from say your house via a garden house is already pressurized so the pump is not needed.

This is so very, very helpful. 

I've seen that diagram (someone posted a link to it, can't reall who but I had saved the url), but didn't fully understand the city water part since my RV doesn't have that currently.  I really don't see myself using it either, so I'm just trying to replicate what I have and totally fumbled / confused the fresh water fill with the city water intake since I didn't know there were two ways some RVs get water into their system! And now I know how to talk about what it is I'm trying to do, which makes describing the problem and what I'm trying to buy SO MUCH EASIER!

THANKS!!!!

Sidenote - if I don't put in a city water intake and just stick with the fresh water fill, do I  still need the one way valve between tank and pump?

[yellowrecve]

Your original tank would have been metal and could be pressurize by the city water  passing through it to the faucets. Your plastic tank stores water to be pumped to the faucets. A modern RV would have  the city water pressure fed  into the plumbing between the pump and the faucet. You do not need this feature. Most modern water pumps have a check valve built into them to prevent the pressure from the city water backing into the plastic tank. The plastic tank is filled by gravity ( a hose ). I hope this makes sense.

[perlgurl]

Also, we finally finished plumbing the new water system AND I finally have an external hot water shower that is plumbed into the water system and a (new) shower tent for privacy! We ended up saving the water input valve after buying two different replacements that did not work. It took a lot of work, over six trips to the hardware stores to buy parts and more money than I thought, but I have cold running water (still need to test the RV hot water heater) and I can take showers when I'm boondocking for extended periods too.

Huge thanks to my hubby Michael for all his amazing hard work to make this crazy idea of mine work.

Yehaw!!!