what pump do I need?

rick in Alaska

thanks for the info guys. I think the tubing might be the SolaRoll stuff. It is black in color and in a twin tube configuration. I can get flow through the entire system by running a boiler drain at the end of the system, so I know it is not completely plugged, if at all.
Weezbo, I had pretty much the same idea for checking the volume of the tube. I probably will have to do something along those lines.
The plate exchanger is 1" and I can flush through it pretty well.
I'm just not sure if the whole system has a lot of added head from the tubing, causing the system to plug up slowly over time.
Also, what can I use with this tubing to flush with so I don't harm the tubing. I'm thinking tsp.
Thanks for all the help.

rick in Alaska

what pump do I need?

I've got a customer that has some of the old style small diameter rubber tubing installed in a gypcrete pour. I am having problems getting the flow moving at more than a crawl. The tubing is tied in through a flat plate heat exchanger with a cast iron pump. As you can imagine, the pump is almost completely blocked with scale. I replaced the pump, but am not getting much better results.
I have flushed out the entire run of tubing and it doesn't appear to be "plugged".
The new homeowner does not have much information on this system, so I am not sure if it has ever ran correctly or if it even has the original spec'ed pump.
My question is, how can I determine how much head pressure I might need in order to size the pump?
The current pump is a 15-42 and I am figuring on using a higher head pump such as a 26-64 or a 43-75.
Any advice much appreciated.
Rick in Alaska

A.J.

> I've got a customer that has some of the old

> style small diameter rubber tubing installed in a

> gypcrete pour. I am having problems getting the

> flow moving at more than a crawl. The tubing is

> tied in through a flat plate heat exchanger with

> a cast iron pump. As you can imagine, the pump is

> almost completely blocked with scale. I replaced

> the pump, but am not getting much better

> results. I have flushed out the entire run of

> tubing and it doesn't appear to be "plugged".

> The new homeowner does not have much information

> on this system, so I am not sure if it has ever

> ran correctly or if it even has the original

> spec'ed pump. My question is, how can I

> determine how much head pressure I might need in

> order to size the pump? The current pump is a

> 15-42 and I am figuring on using a higher head

> pump such as a 26-64 or a 43-75. Any advice

> much appreciated. Rick in Alaska

A.J.

> I've got a customer that has some of the old

> style small diameter rubber tubing installed in a

> gypcrete pour. I am having problems getting the

> flow moving at more than a crawl. The tubing is

> tied in through a flat plate heat exchanger with

> a cast iron pump. As you can imagine, the pump is

> almost completely blocked with scale. I replaced

> the pump, but am not getting much better

> results. I have flushed out the entire run of

> tubing and it doesn't appear to be "plugged".

> The new homeowner does not have much information

> on this system, so I am not sure if it has ever

> ran correctly or if it even has the original

> spec'ed pump. My question is, how can I

> determine how much head pressure I might need in

> order to size the pump? The current pump is a

> 15-42 and I am figuring on using a higher head

> pump such as a 26-64 or a 43-75. Any advice

> much appreciated. Rick in Alaska

A.J.

> I've got a customer that has some of the old

> style small diameter rubber tubing installed in a

> gypcrete pour. I am having problems getting the

> flow moving at more than a crawl. The tubing is

> tied in through a flat plate heat exchanger with

> a cast iron pump. As you can imagine, the pump is

> almost completely blocked with scale. I replaced

> the pump, but am not getting much better

> results. I have flushed out the entire run of

> tubing and it doesn't appear to be "plugged".

> The new homeowner does not have much information

> on this system, so I am not sure if it has ever

> ran correctly or if it even has the original

> spec'ed pump. My question is, how can I

> determine how much head pressure I might need in

> order to size the pump? The current pump is a

> 15-42 and I am figuring on using a higher head

> pump such as a 26-64 or a 43-75. Any advice

> much appreciated. Rick in Alaska

A.J.

Rick your pump size

is going to be based on your head (lenth and size ) of your tubing and your G.P.M. (load). You will need to know those two items before you can know your pump size.

rick in Alaska

extra info

I guess it was pretty late when I posted, so I missed a little info. I do not know how much tubing is in the system as it is already buried. The only way I could possibly figure it out would be to drain out all of the water and measure the volume and compare it to the tubing size. Is there another way to find this info that I am missing? I thought maybe there is a way of doing some kind of pressure check across the tubing circuit to be able to determine it's head pressure drop?

hr

Do you know

the brand of the tubing is? Is it Heatway redish colored? If so it should have foot markers that may be visible. Generally these small diameter systems like Twintran or Solaroll, or early 3/8" Entran were 200 to 250 foot loops.

If you can, connect a hose on one end and see if you get any kind of flow out the other.

I'd be willing to bet the flat plate heat exchanger is plugged. Try to disconnect it and see what flow you get through the HX. Sludge created by early non-barrier systems often ends up in the smallest passage ways. Like a plate HX

Most often the 3/8 tube were designed to work with a typical low head pump like a Grundfos 15-42 or Taco 007, or B&G NRF-22. Rare to see any system needing more than a Grundfos 26-96.

1/4" diameter SolaRoll usually required high head 26-96 or 26-99.

Depending on the HX size and flowrate it was designed for, you could have a bit of pressure drop through it.

Without design data you are just guessing. installing a high head 26-99 probably will not hurt anything, and it may buy some more time.

hot rod




To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

RoosterBoy

i am home for a second...

this might work for you,...go get some propyline glycol and if it is clear a some cherry food colouring,...get a dry bucket,pump a known quantity of glycol into the system, catching the water on the other end in the clean bucket.when it starts to show some colour comming out shut the pump off. thats about how much water is in the line. then get the size of the pipe the manufacturers blah blah blah sheet and do some quick math. now that would be only one length. in order to get the one length though ,i suggest that you do this to two other lines in succession. this is sorta really basic chemistry experiment ...all you would like to have is some fairly close approximation....well, how can this be close or far? well, as glycol is sorta Thicker than water in a sence...it will push the lighter fluid out faster than the glycol....yah well when it starts to turn cherry is sorta vauge... true true yet it is a method that i use on the fly and so far i have been able to tag in pretty close...*~/:)

I too will suggest the X changer is quite likely bogged... so,



....try this idea oon also, run water clean water thru the pipes in the field....if brown or grey or black stuff comes out then it is a fairly sure indication that quite a bit of that is beyond the strainer into the x changer..

you the man ! so now with fresh water in the lines you could run the cherry glycol and it would show up pretty quick in clear water hey?

hab a good day i have to run back and put some escuchens on the boiler piping on this yellow boiler...:)and make sure the zones are all lashed in to the taco zvc...right now it is runnig off its manager and some buffer tank t stats, and the variable speed is running around the 705-2 to make the system sing and dance and hum a habby tune ..Chow

Steve Ebels_3

Does

Does the owner know if the system ever worked? If it did, you're probably looking at gunk induced restriction of flow. Clean it and your pump question is moot. If it didn't work, now you have a whole 'nother set of problems which will have to be addressed with something that will push a little higher head.