flushing heat exchanger, what to use

Mr Googler

Mr Googler

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Hi all

Im going to reverse flush my heat exchanger as the temp is creeping up a bit when blatting. What should I use to make up my crud destroying solution.

My plan is to remove it. Pump a solution through it backwards for a few hours via a bucket and inline pump then flush a couple of times with clean.

What do the learned panel think?
 
My heat exchanger is also due for a clean as part of the maintenance schedule. The book says the heat exchanger and after cooler tube stacks both need cleaning/inspecting at 400 hours/4 years. Just coming up to the 400 hours. The engine is a 4.390 Nanni, 200HP.

What would be considered the most effective method ? Removal and individual cleaning, or back pumping through the whole system ?
 
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I used Rydlyme last weekend as the temp was slowly creeping up at max revs, used a central heating pump and header tank, left it flushing for a coulple of hours, this process was recomonded by volvo when on a course there last year
 
If you connect before raw water pump then you will need to remove the impeller, I connected to the out let of the pump and to the pipe into exhaust water injection bend.
I used a couple of those Vetus stepped pipe reducers to make the connections and the central heating pump circulated really well.
This was the first time have done this so was a bit of an experiment.
 
aquapower said:
If you connect before raw water pump then you will need to remove the impeller, I connected to the out let of the pump and to the pipe into exhaust water injection bend.
I used a couple of those Vetus stepped pipe reducers to make the connections and the central heating pump circulated really well.
This was the first time have done this so was a bit of an experiment.
Click to expand...

Of course, good point ref the impeller. I was under the impression that this was best done reverse flow, but i might be wrong.
 
PaulGooch said:
Of course, good point ref the impeller. I was under the impression that this was best done reverse flow, but i might be wrong.
Click to expand...

The Rydlyme instructions say you should circulate through starting at bottom and out of top of coolers, and refer to the raw water pump as the inlet and exhaust connection as the return, in my case the heat exc. pipe work was this way round and went through the oil cooler and intercooler aswell
 
aquapower said:
The Rydlyme instructions say you should circulate through starting at bottom and out of top of coolers, and refer to the raw water pump as the inlet and exhaust connection as the return, in my case the heat exc. pipe work was this way round and went through the oil cooler and intercooler aswell
Click to expand...

Think that'll be the same way for me then, thanks.
 
aquapower said:
If you connect before raw water pump then you will need to remove the impeller, I connected to the out let of the pump and to the pipe into exhaust water injection bend.

I used a couple of those Vetus stepped pipe reducers to make the connections.
Click to expand...

That's exactly what I did on my Fleming's two Cummins. Used a Gulper 220 pump. Cycled the mix for about 2 hours.

NOTE - don't forget to remove the anodes first and plug the holes, and make sure you use Rydlyme for Marine use.
 
PCUK said:
Manual cleaning by rodding is the most effective method and you can then keep going until it is perfectly clean. The screwed end of a wire coat hanger does a good job and doesn't scratch the tubes.
Click to expand...
You cant always get inside to clean with wire, and descaler will clean everything without the need to dismantle so no new seals needed
 
All done.

OK, so i got the Rydlyme and circulated it backwards for 2 1/2 hours then flush with clean and all went smoothly.

Am I supposed to see anything in the bucket. I expected to see tons of crud come out but saw hardly anything? The liquid did change colour a bit and went from muddy brown to slightly orangy brown.

I guess it all dissolves but just wondered what anyone else thinks.

I did find a bit of impeller in the bucket so thats a result. I knew it would turn up somewhere :)
 
I have used Rydlime a few times with great results.

You won't see big lumps of stuff floating around...the reason for circulating it for hours and hours (but no more than 4 hours if I recall) is that it reacts with the calcium or whatever it is and eats it turning it into a solution.

Sounds to me like you have done just fine...especially with the impeller bit popping out you sound like you have the right amount of "power" coursing through the system.
 
stefan_r said:
I have used Rydlime a few times with great results.

You won't see big lumps of stuff floating around...the reason for circulating it for hours and hours (but no more than 4 hours if I recall) is that it reacts with the calcium or whatever it is and eats it turning it into a solution.

Sounds to me like you have done just fine...especially with the impeller bit popping out you sound like you have the right amount of "power" coursing through the system.
Click to expand...

Thanks stefan
I feel reassured. I just used a little portable sump pump with a length of hose and gaffer tape round the end to increase the diameter a bit. I love this diy lark!
 
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