[Scrub Puller]

Yair . . .

How do you get your hand and wrench inside the glass lined water tank to hold the inside half of that fitting.

It seems different folks are talking about different things. I just assumed the devise had a one inch inlet into which a bush could be screwed and then the pipe screwed into the bush . . . there is no need for any holding on the inside under those circumstances.

Cheers.

[Newfie]

NPSM have the same thread pitch as NPT but are straight whereas pipe threads are tapered. The fitting you need will have an O ring, like a hydraulic hose to make a seal. It's called ORB for O Ring Boss.

Right. In the last 24 hours I learned this as well. Your suggestion to use an existing electric hot water tank got me going on this because I have a 40 gallon one in storage up the mountain in Panama.

The problem is that there are no off the shelf available fittings with 1 inch male NPSM threads. There appears to be no standard applications for this. I chatted with a Grainger tech support who transferred me all the way up to supervisor and came up with nothing. I have an e-mail waiting with Eaton and another with a major plumbing supply co. I talked to another service rep on the phone.....all coming up blank.

Just to review for anyone new reading this........I want to connect a 3/4 CPVC pipe into the female 1 inch NPSM of the hot water tank where the threaded heating elements go.

So, if you got a 1" NPSM close nipple it would do the conversion to male and then you are good to go.

But somehow I get the feeling that using "NSPM" is leading you down the wrong path. Is this an archaic term? What normally screws into this?

[Newfie]

Ibon, whoa, back up bub. Let me check some facts here.

What you are looking to do is to take out the existing 4500watt electrical resistance unit and replace it with a 1500 watt electrical resistance unit, right?

If so why are you looking for a fitting or adapter, the fitting is right on the electrical resistance unit. They cost like $9.

You are getting electricity from your hydro unit right? And you are dumping electricity because you have more than you can use?

If you are getting 110 from the hydro unit then just make the conversion and move on. If you are making 12VDC from the hydro, then get a big ass inverter to change it into 110VAC and plug it in.

The other option would be to get a (approximate) 12,000 watt element, and run it straight off of DC, roughly the same.

Hope I'm making some sense for you.

Don't over complicate here.

[vtsnowedin]

It seems different folks are talking about different things.

More then likely.

I just assumed the devise had a one inch inlet into which a bush could be screwed and then the pipe screwed into the bush . . . there is no need for any holding on the inside under those circumstances.

Cheers.

People in the industry get very used to an alphabet soup of abbreviations for groups of different parts. Doing plumbing every few years or so ( when the last attempt fails) I understand the mechanics but don't have the abbreviation dictionary committed to memory. Yes a one inch to three quarter bushing ( If I call it a bush my wife will slap me) followed by an adapter to whatever pipe is desired will work.

[Ibon]

How about this page
http://www.discounthydraulichose.com/product_p/6405.htm

this item
6405-16-12 | #16 SAE/ORB Male x 3/4" NPTF Female

then just straight npt union?

I think that's right, worth a call.

That looks like it should work. I will give them a call tomorrow. Thanks for all the suggestions. Yes, gotta love the internet for this. And I do need to make sure I travel to Panama with all the right fittings because down there the choices of hardware are very limited.

[Ibon]

you need a cheap frequency drive connected to a small 3 phase circulating pump motor with a feedback loop from an analog temperature sensor that is positioned at the hottest part of the loop.

less than $400 for the components.

Our hydro pelton wheel drives a 220V single phase AC generator. Cannot use a 3 phase motor.

[hvacman]

OK - I am really missing why you're fussing around with trying to connect piping to the straight thread heating element connection. We did a bunch of solar and wood-stove-sourced hot water systems back in the 80's in rural Nor California and used standard electric tank-type water heaters. Didn't touch the heating elements (though your idea of replacing a 4500 W with 1500 watt for load dump is a good one, so long as you tie it into the heater thermostat to turn if off when not needed).

We connected cold water to the tank cold inlet, hot water to hot, We removed the tank relief valve and connected the solar or wood hot water loop hot supply to that connection either on the top or side of the tank. We removed the factory bottom drain valve and connected the solar or wood hot water loop return to the tank drain connection. We tee'ed in a hose bib into the return loop line right after we connected to the tank so we still had a usable tank drain and put in a shut off valve on the loop line so we could isolate it off. We put in a tee at the solar/wood line going into the tank relief valve connection so we could put the relief valve back in the system, with the relief valve temperature tail sticking right down into the tank (Water heater relief valves open both with high pressure and with high temperature. The tail senses the temperature). That kept it all safe, let us use existing fittings, etc. etc. It doesn't have to be hard or expensive.

You also really should look for a mixing/tempering valve to automatically mix the leaving hot water with some cold if required to prevent scalding hot water from getting into the hot water pipes feeding showers and lavs. It is standard issue hardware for current solar hot water systems. Solar can sneak up and get you some really hot water. Gotta play it safe.

Good luck -

Keith

[Ibon]

You are getting electricity from your hydro unit right? And you are dumping electricity because you have more than you can use?

Newfie, I did not want to complicate too much this thread with introducing the whole power distribution challenges at MTCF. But I will elaborate since this has been a challenging undertaking and a collaborative effort of sorts where I have gotten a lot of help, just like I am now from many of you in resolving this fitting.

There is a Yahoo micro hydro group that I am a member of. There have been a couple of folks on this site who have helped me immensely setting up our hydro system, one person actually visited us in Panama. Here is the the site http://microhydropower.net/mhp_group/

Here is a blog entry I did about 15 months ago. Scroll down and you can see our hydro set up. http://mounttotumas.com/wordpress/?p=686

The pelton wheel is attached to a single phase 220V AC generator that puts out about 7.5-8 KW in the rainy season and drops down to about 5KW in the dry season. This might seem like a lot of power but this is now being distributed to an employee cabin, our workshop, two cabins and now the new lodge.

Check out the load controller photo on the blog entry that is the brain of power distribution. I imported this from New Zealand. It prioritizes power to the project and when we are not using power it dumps unused electricity into the cement tank we built. You see the stainless steel panel with 8 electric hot water heating elements? Each channel is 1500W. So when we shut down all power there will be 5 to 6 channels open dumping all 8KW into this tank of water. You need to have this set up so that at all times you have access to full power. If we turn on a 4.8KW dryer to dry clothes the load controller draws off the dump and feeds the dryer and there is constant 60hz 220v so the lights don't flicker etc.

Now with the lodge we built we are adding additional power load on to the hydro and we will exceed what we are generating if I use a standard electric hot water tank. That is the reason for the active solar set up I am pursuing.

Now, you might ask, if you are heating up water in the dump why not just use this? It is possible. the first two channels of 1500W on the dump load actually are probably dumping 3kw for atleast 18 hour a day. I want to use one of these channels and attach it to the electric hot water tank as Pop suggested, to the lower heating element, exchanging the 4500W heating element with a 1500W element. I have another electric hot water tank in one of the cabins that I would like to connect the other 1500W channel from the dump.

If you follow me so far then if the first two channels of the dump load heat up the electric hot water tanks and if the temperature of the tank reaches maximum and the thermostat shuts the unit off then I still have channels 3-8 in the dump load to dump unused power.

Just like a big old electrical grid in a city you only ever generate what you are using and you have to design your system for maximum load. Since my nearest neighbor is 4km away I can't give away power that we are not using. Instead of heating the water in the dump I could freeze water into ice blocks and take them down to town and sell them once a week but you guys all remember The Mosquito Coast movie, right? The locals already think I am kind of wacked out which I admit I am for having undertaken this crazy project so I don't need to draw more attention to myself arriving down out of the cloud forest with big blocks of ice

[Ibon]

We connected cold water to the tank cold inlet, hot water to hot, We removed the tank relief valve and connected the solar or wood hot water loop hot supply to that connection either on the top or side of the tank. We removed the factory bottom drain valve and connected the solar or wood hot water loop return to the tank drain connection. We tee'ed in a hose bib into the return loop line right after we connected to the tank so we still had a usable tank drain and put in a shut off valve on the loop line so we could isolate it off. We put in a tee at the solar/wood line going into the tank relief valve connection so we could put the relief valve back in the system, with the relief valve temperature tail sticking right down into the tank (Water heater relief valves open both with high pressure and with high temperature. The tail senses the temperature). That kept it all safe, let us use existing fittings, etc. etc. It doesn't have to be hard or expensive.
Keith

Keith

Thank you for this new idea. I am not in front of my hot water tank at the moment as it is in Panama and I am up here in the US. It is a pretty standard electric hot water tank so I assume that the relief valve is standard NPT threaded in which case I can find the fittings locally.

I am grateful for all the suggestions from everyone and will post photos in the end when I get this active solar up and running in the next 60 days or so.

[vtsnowedin]

We connected cold water to the tank cold inlet, hot water to hot, We removed the tank relief valve and connected the solar or wood hot water loop hot supply to that connection either on the top or side of the tank.

Again connecting the hot feed from the collector down through the top of a tank does not work unless you use a circulating pump all the time. Bring it into the side ether through a relief valve port if you have one on the side or use the upper heating element port. Then it will circulate all by itself using just gravity.
All the rest of hvacman's method is very familiar as I have built almost the exact same system.

[Ibon]

Again connecting the hot feed from the collector down through the top of a tank does not work unless you use a circulating pump all the time. Bring it into the side ether through a relief valve port if you have one on the side or use the upper heating element port. Then it will circulate all by itself using just gravity.
All the rest of hvacman's method is very familiar as I have built almost the exact same system.

Understood. The collector is not going up on the roof. It will be at the same elevation roughly as the storage tank. I am planning on using a circulation pump since it draws a negligible amount of power from my hydro. Again thanks for your inputs here!

[vtsnowedin]

Here is a rough sketch that shows how I do it. You can add your pump into the cold feed line. There are some variations that also work if your limited by how many holes you have in the tank.

[Shaved Monkey]

http://www.youtube.com/watch?v=ehDgXrpRlTU#t=67
heres another option

[vtsnowedin]

http://www.youtube.com/watch?v=ehDgXrpRlTU#t=67
heres another option

That is rather interesting. It is hard to see but it looks like they are running black plastic pipe up through two liter bottles just cut and nested together to make a dead air space around the pipe. An assembly video would be interesting.

[Shaved Monkey]

Heres more info
http://www.connect-green.com/a-diy-sola ... c-bottles/