Valterra Flush King Extra Parts and Check Valve Placement

[sajohnson]

There are many discussions of the Flush King, but I could not find any that deal with this:

We just got a Flush King and it came with the ball valve installed (the backflow preventer/check valve was loose in the bag). Inside the garden hose fitting, between the ball valve and the clear elbow, was a thin black rubber disc (not a washer) and a thin steel flat washer.

The ball valve will obviously not seal well against a steel washer.

The black rubber disc has a center hole only partially cut out, creating a flap.

I've asked the CSR at Valterra and she could not tell me what the disc and washer are for. So I figured I'd ask if any WinnieOwners members are familiar with those parts.

Also, I'm curious about where people install the check valve and why. The CSR suggested using it at the water source, but I've seen several videos in which the check valve is installed right after the ball valve (clear elbow > ball valve > check valve > garden hose). I'm not a plumber but intuitively, that makes more sense because then the hose and water supply are protected.

Granted, it's not a potable/drinking water hose, but it's still best to keep it as clean as possible. Is there a reason to not do that?

We have a dump here at home which our View is hooked up to. I'd like to flush the tanks before putting it in the garage but I don't want any 'mishaps.' We've had the View since 2012, but I've never used a Flush King.

 

[sajohnson]

Valterra is a decent company so I'm reluctant to not use all of the included parts.

That said, I'm leaning toward removing the included rubber disc and steel washer and using an ordinary garden hose washer or O-ring, like this...:

Clear elbow > hose washer (not included) > ball valve > backflow preventer > Gryvoze water meter > dedicated reverse flush hose...

...unless I hear differently. I'm still hoping to receive input from experienced Flush King users.

 

[l1v3fr33ord1]

I used a Valterra Flush King on my Class C and after I sold that coach and bought a Class A I kept the Flush King in the spares bin. It came in handy several times when helping others with drainage problems.

I don't remember removing the Flush King ball valve, and I don't remember any steel washer. I would connect the parts with rubber washers unless leaks made me rethink that.

The Flush King's 45-degree clear elbow did not work on the Class A. Instead, I modified a Camco straight-through flush attachment, removing its ball valve to get a higher flow rate. [The Flush King throughput is about 4 gallons per minute, the unmodified Camco is about one gallon per minute.] See the attached photo.

I used two supply hoses. One was for drinking water and connected to the short white hose on the right.

The second hose connected to the "tree" on the left, which fed the black tank flush fitting and the back-flush (Camco) fitting, each with its own ball valve. I put the check valve at the coach end of the supply hose. If the rest of the apparatus was contaminated I could easily clean that out. The check valve protected the hose and the water supply.

 

[sajohnson]

I used a Valterra Flush King on my Class C and after I sold that coach and bought a Class A I kept the Flush King in the spares bin. It came in handy several times when helping others with drainage problems.

I don't remember removing the Flush King ball valve, and I don't remember any steel washer. I would connect the parts with rubber washers unless leaks made me rethink that.

The Flush King's 45-degree clear elbow did not work on the Class A. Instead, I modified a Camco straight-through flush attachment, removing its ball valve to get a higher flow rate. [The Flush King throughput is about 4 gallons per minute, the unmodified Camco is about one gallon per minute.] See the attached photo.

I used two supply hoses. One was for drinking water and connected to the short white hose on the right.

The second hose connected to the "tree" on the left, which fed the black tank flush fitting and the back-flush (Camco) fitting, each with its own ball valve. I put the check valve at the coach end of the supply hose. If the rest of the apparatus was contaminated I could easily clean that out. The check valve protected the hose and the water supply.

View attachment 2457512

First of all, you get big points for replying, thank you!

I like your setup, but I have a few questions:

1) You mentioned 2 ball valves, but I only see one (with the white handle) -- unless that's a ball valve after the water meter.

2) There are 2 hoses connected close to the white handle ball valve. One goes to the water meter for the back flush. I'm guessing the other is for the built-in tank flush? If so does the supply connect at the bottom where the grey knob is?

3) You said, "I put the check valve at the coach end of the supply hose." Is that at the grey knob? Is that the check valve?

In any case, that's what I plan to do -- put the check valve at the output of the dedicated back flush hose. As you said that will protect the hose and the water supply. That makes more sense to my non-plumber brain than connecting the check valve to the supply/spigot.

I'm glad to hear that you do not recall a steel flat washer being included. I'm thinking that was just a mistake. Same with the thin black rubber disc with a partial hole cut it the center. Very strange.

I do not plan to remove the ball valve, esp if, as you said, it flows 4 gpm. As of now I'm thinking:

Clear elbow > hose washer (not included) > ball valve > backflow preventer > Gryvoze water meter > dedicated reverse flush hose...

I'm guessing the reason some recommend that the check valve be placed at the water source is that if the hose were to become contaminated somehow, the source would be better protected. Still, it's not as if black water is being run through the backflush hose. That hose carries fresh water under pressure. With a check valve at the outlet it should remain clean.

 

[l1v3fr33ord1]

1) You mentioned 2 ball valves, but I only see one (with the white handle) -- unless that's a ball valve after the water meter.

Yes, that's a black-handled ball valve between the water meter and the (modified straight Camco) clear adapter. By having a ball valve and flow meter on each flush line I could keep track of, and control, the total water flow into the black water tank. The grey water tank did not have a built-in flush attachment, so I could only use the back-flush to flush the grey tank. Note: I could fill the black tank (built-in connection) at the same time I back-flushed the grey tank. This saved a bit of time, but I had to stay focused or otherwise I'd fill the black tank with fresh water and cause an overflow through the toilet and vent.

2) There are 2 hoses connected close to the white handle ball valve. One goes to the water meter for the back flush. I'm guessing the other is for the built-in tank flush? If so does the supply connect at the bottom where the grey knob is?

That grey "knob" is a male plastic cap for the "tree." If you look closely you'll see a hatch in the floor aligned with the "tree." [I added that hatch.] The "tree" is held to the wall with the two black clips. When it came time to set up, I would open the hatch, insert a foam piece, release the "tree" from the clips, insert the "tree" through the foam piece, then close the hatch. The "tree" was now vertical with the cap protruding below the wet bay floor. I would remove the cap, attach the check valve and then attach the water hose from the hose bibb to the check valve. Ready for rinsing.

3) You said, "I put the check valve at the coach end of the supply hose." Is that at the grey knob? Is that the check valve?

Explanation as above.

 

[sajohnson]

Yes, that's a black-handled ball valve between the water meter and the (modified straight Camco) clear adapter. By having a ball valve and flow meter on each flush line I could keep track of, and control, the total water flow into the black water tank. The grey water tank did not have a built-in flush attachment, so I could only use the back-flush to flush the grey tank. Note: I could fill the black tank (built-in connection) at the same time I back-flushed the grey tank. This saved a bit of time, but I had to stay focused or otherwise I'd fill the black tank with fresh water and cause an overflow through the toilet and vent.

That grey "knob" is a male plastic cap for the "tree." If you look closely you'll see a hatch in the floor aligned with the "tree." [I added that hatch.] The "tree" is held to the wall with the two black clips. When it came time to set up, I would open the hatch, insert a foam piece, release the "tree" from the clips, insert the "tree" through the foam piece, then close the hatch. The "tree" was now vertical with the cap protruding below the wet bay floor. I would remove the cap, attach the check valve and then attach the water hose from the hose bibb to the check valve. Ready for rinsing.

Explanation as above.

Understood, thanks!

Is your reasoning regarding the placement of the check valves at the end of the hoses (rather than at the spigot) the same as mine -- that then the hose and water supply are protected?

The Valterra CSR recommended that the check valve/backflow preventer be installed at the spigot, but that seems to create more of a risk that the hose may become contaminated.

 

[l1v3fr33ord1]

Either check valve location will do. As you say, at the downstream end it protects the hose.

More important to me was to have as little stuff, especially plastic, at the hose bibb. I spent three Winters at a Florida RV park which had supply pressure at or exceeding 100 psi at the bibb. A Watts 263A regulator (link here) came first, to knock that back to 65-70 psi. Next was a set of metallic wye-shaped ball valves. The white (potable) and green (non-potable) supply hoses connected to the valves. The entire "Christmas tree" sat in the sun every day, almost all day. I was concerned a plastic check valve would fail in that service and location.

By the way, the above paragraph lends credence to those who run on their fresh water tank and water pump. Leaving the hose bibb "permanently" pressurized can lead to major leaks outside the coach, not just inside. I chose to take that risk with the potable water, but kept the green flush hose depressurized/drained when not in use.

Note: In between the bibb and the coach I (eventually) installed an On-the-Go double water softener (link here), with its own upstream particulate filter.

Note: You can see in my picture a Fairview 55 psi fixed-pressure regulator (link here), attached to the water filter inlet. That established final house water pressure.

If someone charged me with obsessively rinsing my coach's tanks, I'd plead "guilty." I could hide behind the fact that the tank level indicators would not work well with even slightly-dirty tanks, but even that is a dodge/excuse. Famous former iRV2 member "Old-Biscuit" recommended running off the fresh water tank, dumping the black tank when the toilet "burped," refilling the black tank with a few gallons of water and getting on with life, instead of managing a complicated supply and flush system. "To each his own," as they say.

 

[sajohnson]

Either check valve location will do. As you say, at the downstream end it protects the hose.

More important to me was to have as little stuff, especially plastic, at the hose bibb. I spent three Winters at a Florida RV park which had supply pressure at or exceeding 100 psi at the bibb. A Watts 263A regulator (link here) came first, to knock that back to 65-70 psi. Next was a set of metallic wye-shaped ball valves. The white (potable) and green (non-potable) supply hoses connected to the valves. The entire "Christmas tree" sat in the sun every day, almost all day. I was concerned a plastic check valve would fail in that service and location.

By the way, the above paragraph lends credence to those who run on their fresh water tank and water pump. Leaving the hose bibb "permanently" pressurized can lead to major leaks outside the coach, not just inside. I chose to take that risk with the potable water, but kept the green flush hose depressurized/drained when not in use.

Note: In between the bibb and the coach I (eventually) installed an On-the-Go double water softener (link here), with its own upstream particulate filter.

Note: You can see in my picture a Fairview 55 psi fixed-pressure regulator (link here), attached to the water filter inlet. That established final house water pressure.

If someone charged me with obsessively rinsing my coach's tanks, I'd plead "guilty." I could hide behind the fact that the tank level indicators would not work well with even slightly-dirty tanks, but even that is a dodge/excuse. Famous former iRV2 member "Old-Biscuit" recommended running off the fresh water tank, dumping the black tank when the toilet "burped," refilling the black tank with a few gallons of water and getting on with life, instead of managing a complicated supply and flush system. "To each his own," as they say.

You've got some nice equipment.

It's definitely a good idea to use a pressure regulator and avoid plastic in a situation like you described! I've considered getting one but we've never had to deal with high pressure like that (maybe once). We often dry camp, boondock, or stay with friends/family. When we have a city water source we add water to our fresh tank and then turn the supply off -- for the reason you mentioned. Still, it doesn't hurt to have a regulator. Actually, I do have an inexpensive brass one but I'm not sure how effective it is.

It never occurred to me to install a water softener. We have a View so our space is limited. I doubt the softener would fit. Did you have issues with hard water?

There's definitely nothing wrong with keeping the tanks reasonably clean. What led to me buying the Flush King was a first ever clog that prevented the black tank from draining. Before it arrived, I was able to clear the obstruction by filling the grey up and using that grey water to (sort of) back flush the black. So I'll be using the Flush King for flushing both tanks. Something else that happened for the first time is that the black tank sensors stopped working. Hopefully backflushing will fix them.

In our View, we have a standard size (2.5x10") 1 micron sediment filter in a clear housing before the city water inlet. It flows surprisingly well for a 1 micron filter, very little restriction. There is a PUR filter on the kitchen sink faucet, and we use a Brita pitcher with their better quality blue filter. The data sheets for those two filters are more impressive than I expected, given their size. They both have an NSF 53 rating.

The filters are generally not necessary since we never use well water. It's more like a 'can't hurt' situation. Here at home we have better filtration -- a 4x10" whole house 5 micron Pentek sediment, and Omni CB1 and CB3 under the kitchen sink. Again, probably overkill because while we have well water we are on the side of a small mountain in a 'resource conservation' area with nothing but woods around us. That said, my thinking is that well water can test good and become contaminated a few days later, so it's better to filter it.

I'm still stumped by the black rubber disc and thin steel flat washer included with the Flush King. I still plan to make the connection like this:

Clear elbow > hose washer (not included) > ball valve > backflow preventer > Gryvoze water meter > dedicated reverse flush hose...

The water meter is cast metal and brass, so I'm a bit concerned about placing too much stress on the female hose fitting on the clear elbow. I'm thinking that using a short (6") section of hose between it and the backflow preventer might help.

 

[sajohnson]

Here's a photo of the thin steel flat washer and rubber disc that seem to serve no purpose. They are identical diameter and fit inside the female hose connector on the clear elbow:

 

[sajohnson]

FYI, I received the following email from Belinda at Valterra earlier today. My reply follows:
~~~
I was able to get more information on the washers.

The thick rubber disc with partially cut flap is a rubber check valve diaphragm. The slit / flap allows water to flow one direction during backflushing, while helping prevent sewage or contaminated water from flowing backward toward the hose connection.

The thin steel washer acts as a retainer / support washer for that rubber diaphragm so the water pressure doesn’t distort or pull the rubber out of position.

The order for putting them together is following:

1. Steel Washer
2. Rubber/flap disc
3. Spring cap or fitting body pressing against them

Note: the rubber flap should face the direction of normal water flow.

Thank you,

Belinda

~~~

Hi Belinda,

Thank you very much for getting back to me! That's very helpful information!

I can see how the rubber disc and flat washer work together as a very basic one-way/check valve. It's better than nothing, but the rubber flap is likely to break off eventually. When that happens the user would have no way of knowing.

I am confused by the order of assembly. Starting with the clear elbow, I'd think it should be:

1. Rubber/flap disc inserted first, then
2. Steel Washer (so the flap can only open inward, not out)
3. Rubber washer or O-ring (not included) to seal between steel washer and hard plastic ball valve. Online reviews mention water leaking from inside the clear fitting.
4. Ball valve
5. Backflow preventer/check valve -- actually an "anti-siphon valve." See below.
6. Water meter (optional, but helps prevent tank overflow)

I'm not sure what the 'spring cap or fitting body' you mentioned is.

By the way, I noticed that the diameter of a standard hose washer is too large for the clear elbow fitting. Does Valterra use a special smaller size?

I just realized that what I (and, in my defense, others) have been calling a backflow preventer/check valve is actually an "anti-siphon valve." From Google:

"For RV use, an anti-siphon valve (a type of vacuum breaker) and a backflow preventer (like a standard check valve) are fundamentally different devices. They should never be used interchangeably, as they serve different safety functions for your camper's water systems."

See this image from Amazon:
Amazon.com

In the image at the above link, it says "removable anti-siphon valve." Why would the user want to remove it?

Thank you.