What's a word for the opposite of Primary-Secondary piping?

JohnNY

Is there a word for sending the whole system through the boiler or should I invent my own term? Direct Flow Piping? Mono-Loop Piping? I've been saying "standard" but it always requires explanation.

Canucker

That's what I've always called it. If the system is hydraulically separated from the boiler loop, it's primary secondary. If the system pump generates flow to the emitters and the boiler, it's piped "directly". If you said you set it up with direct flow piping, I'd know exactly what you were referring to

hot_rod

Direct or direct to boiler piping, maybe

AMservices

Looped system 

psb75

Its a good question. Language is important. Common terminology would help folks on this forum convey clear information, if there WAS a proper, common term for what you are asking about.
Say, wasn't this forum founded by a well known writer with a thorough knowledge of hydronics? Maybe he has the term you're looking for!

mattmia2

Anyone look at what modern hydronic heating and idronics call it?

EBEBRATT-Ed

Take your pick.
From Modern Hydronic Heating

Series loop is called 'Single Series Circuit"
One pipe is called "single circuit multizone"
Then there is "Multi zone with zone valves
Then there is "Multizone with circulators"
"Parallel with direct return"
"Parallel with reverse return"

Alan (California Radiant) Forbes

For what it's worth, "direct connection" used as a verb, not a noun:

DanHolohan

I would say primary. That’s a naturally linguistic introduction to primary-secondary. One proceeds the other. 

jumper

I think chilled water systems are called direct (pumping) if they don't have a shunt (bypass) pipe to allow different flow rate through chiller than through system. Primary-secondary for CW are no longer in favor.

JohnNY

Thanks, guys. Good answers here. It's best to standardize the terms and it comes up quite a bit in our industry.