Mono flow refers to the direction of flow through the tee which is a venturi tee. As water is forced through the venturi it creates an area of low pressure on the back side (like a carburetor) and the resulting low pressure area pulls water through the radiator. It is a one pipe system in that one single large loop of pipe is usually run around the basement and 2 tees, 1 monoflow and 1 regular, feed and return each radiator. Been around a long time. I'll see if I can dig up a schematic and post it here. May have to scan it in if I cant google it.
Found this, not great but better than nothing.
Yes but compared to Steam which CAN be run with one pipe, as in ONLY one pipe from the boiler and the supply/condensate shares the same pipe, wouldnt the venturi system be more of a supply/return system. One would still have to use a circulator and Flow Checks with any of the others? Ok I change my Answer.... I say yhtat the 2 pipe system is Venturi or Mono Flow, Becasue any of the other systems is essentially just a loop, where as the Venturi system has the loop AND supply and return :idea:
I don't think any of the regulars here don't know what a monoflo is.
When I hear "one pipe system" I automatically think steam.
I have seen gravity hydronic systems, but this one is new to me...you learn something new all the time in this trade:
Well Duck that is becasue the majority of the regulars are from California where it is sunny and 65 degrees all year long. Its funny, in the North East its mostly Joe Shmo Plumbing and Heating, anything south of PA is Joe Schmo Plumbing and Drain Cleaning!
i misunderstood the original question.
before the invention of aquastats, electric zone valves and such, is it possible the monoflo/1 pipe/hwh gravity sysytem was the pre-curser to the 1 line steam heating system?
i don't think there is such a thing as a 2 pipe system that incorporates a monoflo tee. but i may be floating on a ice pan in the middle of the bay one this one.:D
i was taught that a 2 line hwh system was called a reverse/return system which means the first rad supplied (shortest supply) is the first one returned(longest return). then balancing valves where used to control the temp. for each rad. and allow for variables unforeseen on the drawings.
am i suffering from willnots desease?
A couple more piping diagrams that may help you out.
These two do not require a monoflow tee.
One pipe gravity water did indeed take pretty big mains as well as risers. Typically there would be an open expansion tank mounted in the attic to keep pressure on the system. Because the tank is open filling the system was a tricky proposition. Many tanks had the overflow piped down through the house to a location fairly close to the fill valve. When you got a shower, the system was full. Controls were rudimentary also. Usually a high voltage thermostat run through a single high limit aquastat to the oil burner primary (mercury stack switch) (goolge Penn Controls)