Combined parallel and counterflow main?

Patrick_North

<span style="font-size:12pt">In the dreaming stages of having my steam mains  repiped- the system has loads of redundant piping because the house was at one time a up/down duplex. To cut to the chase, it would be convenient to run one main as paralell flow for most of its run, drip the main, then continue another 12’ or so as a counterflow main to serve three final rads.</span>

<span style="font-size:12pt">Is this done? If so, any gotchas to be aware of?</span>

<span style="font-size:12pt">Thanks,</span>

<span style="font-size:12pt">Patrick</span>

Jamie Hall

If...

it's big enough and you can pitch it right, no reason it shouldn't work.  You'll need a vent at the end of it...

Steamhead

We've done it

make sure the load on the counterflow portion doesn't exceed that of the next smaller pipe size, if that size is being used as parallel-flow. And the main vent goes at the end of the counterflow portion, as Jamie says.

Rod

Dual Drips

Hi Patrick-

   Someone else asked this question a few months back and it resulted in the attached drawing. Disregard the pipe sizes in the drawing as they were unique to the previous discussion.

 The idea of using an individual drip at the end of each main was to prevent the condensate from the parallel flow pipe and the condensate from counterflow pipe from colliding with each other as they might do entering a single tee. Whether this is really necessary I don't know, but as it is so easy to install, the extra drip capacity can't hurt.

Just a thought for your consideration.

- Rod

Steamhead

Here's how we did it

the parallel-flow section comes down into the tee, the counterflow section goes off to the side, and we even put in a dirt cap. The steam and condensate from the parallel-flow main travel down, and keep out of each other's way at the tee.

Patrick_North

Aha!

Brilliant, thanks guys!

Patrick