radiator valves

TB1

First time posting in a looooong time.  I need some tech support if possible.



I have a job with noisey radiator valves.  Cast iron radiators, hot water,  Danfoss 013G8018,19, &24.  (3/4" and 1" valves w/ operator)



Evidently, 7 valves were installed on the wrong side of the radiators, from day one, and the new residents don't like the squeeling valves.  If there ain't any reverse flow valves made, I'm gonna have to swap the valves to the other side of the radiators, which ain't gonna be fun, so I'd like to avoid that.



Anyone make a radiator valve designed to be installed on the outlet side of the radiator?

Mark Eatherton

Backwards valves generally THUMP, THUMP, THUMP

Not squeal.... It sounds to me as if possibly you have a high head, over capacitied pump that is causing the TRV's to act like pressure activated bypasses. You will KNOW when you have a TRV installed backwards, they either THUMP, THUMP THUMP when close to set point, or will KNOCK, KNOCK, KNOCK.I would suggest either installing one of the new variable speed constant pressure pumps (WILO Eco or Grundfos Alpha) or a pressure activated bypass around the offending pump and your problems should go away. If it IS knocking or thumping, Oventrop makes a reversed inlet/outlet valve, but based on your use of the squealing term, I don't think they backwards..Quick test, close of all but one of the offending valves, then SLOWLY turn that valve down. If when it gets close to shut off point, it starts thumping, it is in backwards. If it just HISSes and squeals, the pump has too large of cajones.ME

DanHolohan

Mark,

couldn't he just turn the valve bodies around? Leave them where they are?



Thoughts?

Charlie from wmass

Just a guess here

Dan not if they are angle valves. Also even if they were straight valves they would now have to fit in a nipple and a coupling as the valves are female flowing to male. I am willing to bet the pressure releif or the variable speed pump wil help with the squealing, or they need rebuilt and cleaned out. Are you positive they are backwards?

Steamhead

Sounds like they're backwards

check the flow direction arrow and trace out the piping to be sure. If they're not backwards, the circulator may be too big, variable-speed notwithstanding. 

Mark Eatherton

If only it were that easy....

Unfortunately, or fortunately depending upon your perspective, the TRV manufacturers matched the pattern used by the original hand wheel valve makers, and there is a union tail piece that typically goes into the bung fitting on the radiator, thereby eliminating the possibility of flip flopping the valve in place. The end to center dimensions of the valve are different for the horizontal to vertical dimensions vs. the end of tail piece to center of valve dimension. That coupled with the fact that the TRV mounted operator would then be above the valve, causing it to pick up false heat, causing it to shut down prematurely, disallows the possibility to easily flip flop the valve in place...



But it can't hurt to ask :-)



The reason the backwards valve will THUNK is because it is a needle and seat type of valve, that is designed to close off AGAINST flow. When water is flowing backwards through the valve, the needle gets suck into the seat, thereby causing the unmistakeable THUNK ,THUNK, THUNK, THUNK.



ME

DanHolohan

I was thinking baseboard.

There was this job years ago in Glen Cove here on the Isle of Long where they got the pipes backwards and we were able to flip the valves. They were straight pattern and two-pipe baseboard going through apartments sure would be easier than free-standing radiators. Just popped into my memory and led me down that path. :-)  Oh, and you're right about the sound. I thought someone was firing a machine gun in that building. We got lucky, I guess. Thanks, Mark. 

Mark Eatherton

And if it WERE BBR, you would be correct....

Been there, had to do that. With a 2 way, straight valve, it will work, but with standing cast iron angle valve, it won't. You can switch it to the other side of the radiator, but can not flip flop in place.



ME

Bill_17

Noisy radiator valves

The posted information is correct, a water hammer is a sign of a reverse flow condition and a true squeal or sometimes described as a whistle, is typically too much velocity.  But sometimes the customers consider a fast hammer as a squeal, so verify the flow direction before changing anything.  If the valves are indeed in the wrong direction, leave them there and put manual adjustment handles on them and leave them wide open, then install new radiator valves (valve bodies only) on the opposite side of the radiators and re-use the thermostatic controls.  You will save time and money in the end.  If all offending valves are on a common riser and are "backwards", then you can re-pipe the supply and return in the basement or other hidden area.  Hopefully these tips help.