Connecting a pipe without draining the system

[ditchcrawler]

in the pipeline industry we call it a hot tap.

to insert a tee piece would only cost about a million dollars for a 48inch steel line in oil service.

let me know if you need contact details.

 

 

 

 

...................... coat

 

 

 

seriously, my advice would be to practice and then just do it, with loads of towels. you may actually be disappointed how little water drains out. if the system is not open to atmosphere it tends to contain itself quite well. so close or plug any vents or pipes which are open to air.

You can "hot tap" a washing machine into copper pipe for about a tenner

 

Maybe you should have used this reply to people who want to weld on diesel tanks.

[blackrose]

I use one of these http://www.plumbworld.co.uk/monument-mon2645-plastic-616-95472

 

Much quicker than these http://www.plumbworld.co.uk/adjustable-stainless-steel-616-2613

[Bill]

I reckon wine corks (or the plastic equivalents) will fit nicely inside 22mm pipe. I think I can do the job without draining the system and without spilling more than can be absorbed by a big towel.

 

If it all goes wrong I'll just have a few buckets handy and drain the system that way. Nothing to lose trying a shortcut.

 

 

If you are working on a central heating system (not sure, as i don't think you said exactly what system you are intending to work on) and it has a header tank, put cling film under the filler/breather, turn off all the individual rads and if possible isolate the boiler circuit. That should minimise any free coolant movement. If you can get a helper/assistant all the better, cut the pipe (assume using plastic pipe loppers) and hold your hand over the joint (pipes still facing each other as if still one piece), slide other hand close, then quickly part pipe and put thumbs over the pipe ends. You are now holding the end of a pipe in each hand with your thumbs stopping any leakage. Get your assistant to get either your bungs/corks or a bit of plastic bag/sheet and get ready to cover the ends one at a time. quick movements should see both ends of the pipe safely corked or covered (elastic band or bit of tape to hold the plastic sheet/bag). You now have time to tackle the fittings one at a time. If you have no assistant you are probably still sitting with a bit of pipe in each hand with your thumbs over the end

 

Yes i have done exactly this procedure and it does seem to work ( a non dopey assistant helps, as does room to get in position), I recon i lost less than a teacup of coolant.

 

HTH

[ridders]

hi blackrose does the system have a header tank?

[bizzard]

In order for Alan Blackrose to carry out this Tee-piece operation without faltering,dithering or fumbling nervously,i think he needs to Phsyc himself up to a real buzzing pitch, and get his Adrenaline running furiously beforehand,perhaps by performing such acts like banging his head on a post and Karate chopping Breeze blocks in half,whilst making all the appropriate animal like grunts and shouts.

This behavior works wonders for ones confidence if a little nervous of tackling something.

[Rebotco]

In order for Alan Blackrose to carry out this Tee-piece operation without faltering,dithering or fumbling nervously,i think he needs to Phsyc himself up to a real buzzing pitch, and get his Adrenaline running furiously beforehand,perhaps by performing such acts like banging his head on a post and Karate chopping Breeze blocks in half,whilst making all the appropriate animal like grunts and shouts.

This behavior works wonders for ones confidence if a little nervous of tackling something.

 

 

And then the little men in white coats arrive ...............

 

Brian

[bizzard]

And then the little men in white coats arrive ...............

 

Brian

After the jobs done though.

And sit on a cornflake to wait for the van to come.

[blackrose]

If you have no assistant you are probably still sitting with a bit of pipe in each hand with your thumbs over the end

 

 

Yes, that'll be me!

[blackrose]

hi blackrose does the system have a header tank?

 

Yes it does.

 

I should explain exactly what I'm planning to do:

 

The backboiler on my stove is currently connected via 2 of its 4 outlets (top right/bottom left) to a small central heating system feeding 2 small rads by thermocycling with no pump. The other 2 outlets from the backboiler are blanked off. Although the rads get hot, in the depths of winter when I bank up the stove the system thumps which I have learned means that it's overheating and the system isn't large enough which means that the backboiler will eventually corrode through. I origially thought it was ok and wasn't going to change it, but I now accept that it's not right.

 

I also have a separate central heating system consisting of 4 rads and a calorifier which were origially connected to a now defunct and discarded eberspacher DW10. This central heating system is now indirectly connected to the engine via a small tubular heat exchanger and a 12v circulation pump. That system works well and allows me to heat the boat when I'm on the move without lighting the stove.

 

Now I'm thinking of Ting in the 2 blanked off backboiler outlets to the flow and return of the 4 rad/calorifier central heating system (Ting in about 2/3 of the way down their length from the pump). This will mean that it can thermocycle around the 2 rads as usual, but before it gets too hot and starts thumping I can switch on the circulation pump and also run the backboiler through the second system which will act as a larger heat sink and should also give me hot water.

 

It sounds like a complicated system but it would be very easy to connect the two systems. The reason I'd rather not drain the system is that it took me ages to get all the air out of the pump, but perhaps I should drain it and put in a proper bleed valve.

 

Can anyone think of any reason why this hybrid thermocycling/pumped system would not work? Both central heating systems have their own header tanks.

Edited December 1, 2011 by blackrose

[andywatson]

A couple of thoughts:

As soon as you have interconnected them, both systems header tanks will also be connected so if they are at different levels the higher one will flow to the lower one.

If they are close together and the same height this shouldn't be a problem.

- why not disconnect one in this case?

 

I have actually carried out a system modification with fluid and anti freeze in the C/H system similar to what you are intending.

And I got away with it!

 

Precautions:

-Have all the fittings you need and plan how you will use them.

-Turn off the header tanks and as many other valves as possible to reduce the flow to your tapping point avoid draining radiators etc.

-Have some towels handy.

-Have an assistant to help as you'll soon find you need 4 hands. (maybe even 6 if you get cocky)

-Consider having some slip-on stop ends available.

(these are always worth having around anyway)

Take a deep breath and go for it.

[blackrose]

Thanks, I hadn't thought about the dual header tank problem.

[Tacet]

If I understand it right (probably not!), when you are heating the rads with the engine, your modification will result in the hot water passing through the back boiler and some of it will disappear up the chimney. Probably not a deal breaker - more of a consideration.

 

Ian

[blackrose]

If I understand it right (probably not!), when you are heating the rads with the engine, your modification will result in the hot water passing through the back boiler and some of it will disappear up the chimney. Probably not a deal breaker - more of a consideration.

 

Ian

 

You're certainly correct that when I'm running the engine and switch on the pump to heat the rads, linking the two systems will mean that the backboiler in the stove will also get hot. The stove is a big bit of cast iron and a big heat sink. Although some of that heat will go up the chimney it doesn't really matter - after all, most of the heat we produce in our stoves when we have a fire goes up the chimney.

 

Edit: I suppose I should be able to isolate the backboiler pipes from the rest of the pumped CH system, just in case the stove happened to be on and I was running the CH system from the engine. It's unlikely, but in that case a hot stove might heat the engine above it's normal temperature via the tubular heat exchanger.

Edited December 1, 2011 by blackrose