zone valves

dee davis

Thanks very much for your insight on this. I see on the State Supply website that they have V5011N series valves and they have a ML6984A1006 actuator.
If you don't mind me asking how does this actuator differ from the models you have recommended?

dee davis

zone valves

I'm in a house that's on city steam and have a two pipe system that has six zone valves in the basement. These valves operate okay, when you call for steam the valves trip on and off fine. The problem is that I think they may be leaking steam slightly beyond the Zone valves. The lines on the other side of a closed valve are always hot. I even have a few lines right up to the raditors that are hot without the zone valve ever being tripped on. So what dies first on a zone valve? The actuator? The actual valve? Do you replace both or do mantenence on the current model? All this heat radiating from the basement has kept the thermostats from tripping on but It's probably not the smartest way to run things. Thanks for any advice.

Bill W@Honeywell

Can we have some more info?

Manufacturer & model? How old are they? Possibly the steam pressure is exceeding the close-off rating of the valves or the plug/seat assembly may be damaged or worn out. The actuator may be worn out. Some valves may be rebuilt, others require replacement.

dee davis

zone valves

Well I have attached a picture. Pretty scary stuff! Most of them are Honeywell I think two are Barber-Colman. Not sure which models but I think you might be able to tell some age from the covers in the dirt below. There is a pressure gauge next to the main line from the street. It never reads above 10 pounds.
I haven't checked the seats. (They might all be bad) I did put new packing in two zones over the summer. My dear old landlord managed this mess from about 1946 until last year and now it is my responsibility. He taught me a lot but there's still much I have to learn on this steam business.

Brad White

How are the traps?

A malfunctioning trap or more specifically a pair or more of malfunctioning traps can pass steam from a condensate side into the steam side (back through an stuck-open trap into an otherwise closed radiator). Just another variable to eliminate.

Another thing to look at is if a piece of crud, rust, welding bead, etc. fell on the valve seat preventing it's full close-off.

Bill hit on the idea that the steam could be lifting the seat which means either too much line pressure (yikes- many even low-end valves have a 45 PSIG minimum close-off). This also indicates a possibly failed actuator, one of the first things to go.

Bill W@Honeywell

Those are very old Honeywell V4045/2045 valves...

and they are obsolete for at least 10 years. They probably are worn out. The closest replacement would be a V5011N2XXX series linear flow steam valve, and a suitable ML6420 or ML7420 direct coupled actuator. These are available from a Honeywell commercial wholesaler, and will require more room to install than the others. You also will need new 6000 or 7000 series controllers to make them work. Go to www.customer.honeywell.com, and scroll down to the right hand corner, type in the numbers above for a PDF of the spec sheets. This job needs a pro.

dee davis

re:How are the traps?

I'm sure the traps are in as bad of shape as the zone valves. luckily, I have slowly been putting b&j cage units when I can muster the energy. Have any advice on removing the caps of the radiator traps a little easier? I have my socket and my 5ft pipe that is my leverage. I was thinking about borrowing one of those impact wrench things but, as a girl who has no knowledge of such tools it may be dangerous in my hands. Who knows?