Split Steam System For Church

SuburbanHVAC

I will be replacing a 550,000 btu steam boiler with a split 6" supply.

One side supplies 1430 sf of steam to the second floor while the other

side supplies 760 sf of steam to the first floor. It is a one pipe

system but the returns are connected within the walls.







My thoughts are to install thermostat controlled steam valves on each

side to separate (and zone) the two floors. If I cut in a drip legs on

the radiator side of the steam valves and tie them into the return,

will that keep the system from banging?







Any advice for this type of installation will be greatly appreciated.

Jamie Hall

Should work --

after all, it is sort of like using king size TRVs.



However, a couple of thoughts.



First, those drips by the valves are absolutely critical.  Can't get by without them.  Just make sure that you have adequate A dimension, though, up to the steam main, as otherwise there is a real risk of the wet return water pushing back up into the main.



Second, resist the temptation to use reduced port or globe valves.  You are dealing with saturated steam, which does not take kindly to any short restriction in flow.  You must use full port ball or plug valves in this type of application -- this observation is based both on theory and on field observation.

SuburbanHVAC

Split Steam System

Thanks Jamie, any idea who carries a full port motorized steam valve?

Jamie Hall

Good grief

it's been some time since I've gone looking for big motorized valves... no, honestly, I really don't know who makes them -- or carries them.  I do know they exist, though!  I know Hammond makes flanged gate valves in larger sizes (and a gate valve will work), but I don't know about actuators... Honeywell makes an incredible range of valves, and actuators.  I'd probably contact a Honeywell dealer and see what he could do for me.

SuburbanHVAC

Still Looking

I've had no luck so far, but I'll keep looking. Thanks.

MikeyB

Electric Ball Valves

Hey Surburban, check out Graingers website, I came across DynaQuip Control valves, steam rated, full port, 24v, 120v, might be what you are looking for. You can also check out Dwyer Instruments,Inc