Primary/secondary piping

Paul_34

On a primary loop how close can there be 90 degree fittings from spirovent and pumps.

hot_rod

2-4 pipe diameters

is one rule of thumb, try not to close couple the ells downstream of the pump.



However many of the "boxed" and pre-built panel piping systems have components close coupled on the inlet and discharge side of the circs to save space.

Paul_34

#

I can do 10"-15" from elbows to pumps and spirovent. Do you recommend piping into secondary circuit vertical from hoz. primary loop tees.

hot_rod

piping off P/S

I would suggest every connection to a P/S have check protection. Ghost flow is always a potential, and it depends on many factors as to how much un-wanted flow you could see.



Most circs have checks installed so one side is covered. A spring check or zone valve would assure the other side is protected.



Consider a hydraulic separator also. These multi purpose devices provide excellent air, dirt, magnetic separation, in addition to eliminating the primary loop piping. A true 4 in 1 device.



It also eliminates the temperature drop you see as you take off the primary loop. Every branch teed into the separator will see the same temperature.



It cleans up the piping, saves time and money on the installation, and assures that all the circs behave with one another regardless of their size and brand



Several brands to chose from, here is one that I am familiar with.

Paul_34

#

On a single zone on the secondary loop would you install check valve and flow check valve. Have anybody used the flange flow checks from webstone.

NRT_Rob

yes

IF the primary loop will run for anything other than this zone.



if this zone is the only thing running, I would be looking hard at why I was doing primary/secondary in the first place.