what the heck is this?

norfitz

My customer found this mystery device in a hydronic job. The second pic shows the tag that hangs from it. Anybody recognize it? Sincere thanks for reading this post.

rick in Alaska

From the shape of it, it looks to be some kind of venturi. Is it on a heating line?
Rick

Jamie Hall

Almost certainly a venturi flow meter. Connect pressure gauges -- or, better, a differential manometer -- between the two taps and you can get a remarkably accurate and instantaneous reading of the flow in the pipe. From right to left, in your photo 6

norfitz

Rick in Alaska, yes, it's on a heating line, but the piping seems pointlessly convoluted. It's on a supply line that leads to both a pump and a bypass. The drawing, by my customer, shows the device is where the empty circle is drawn near the top right.

norfitz

Thanks, Jamie. Now we will have to figure out why it's there!

bob_46

It looks like the venturi is in a bridge with a primary secondary loop originating from the bridge. I think??

Terry O

Venturis have been used for injecting boiler treatment chemicals.

JUGHNE

It does resemble the foam injectors used on fire hose nozzles.
Connect a 1/4" hose that is inserted into a bucket of Class B foam, adjust the flow rate and apply to gas/oil fires. FWIW

Jamie Hall

The injectors use the same principle -- the venturi principle -- to get a below atmospheric pressure in the throat, which sucks in whatever. The beauty of the arrangement is that the reduction in pressure is proportional to the square of the flow, and is completely predictable.

Other applications of the same principle perform the seemingly impossible (but quite reliable!) job of using low pressure exhaust steam to inject water into locomotive steam boilers. Fascinating gadgets. For that matter, the jet pump commonly used in smaller residential applications is another variation.

But I'm quite sure that the one in the picture is a flow metering venturi, because of the two required pressure taps (throat and upstream) which are shown.

hot_rod

Looks like a .23 gpm or 23? balance valve, the ports are used to confirm or read the pressure drop across the Venturi.

bob_46

This is the brand I used to use although the brand name changed from Barco.

hot_rod

bob said:

This is the brand I used to use although the brand name changed from Barco.

Excellent info on how sentries works in fluid flow, thanks

BerntKruse

Probably a venturi flow meter. Brass? However, seems a bit like an OEM.

Leonard

Because of the 2 red pressure taps on what looks like a venturi I'ld say its a flow meter. One pressure tap should be at smallest dia section of the venturi. and other tap at a full diameter section.

Jean-David Beyer

Another device, that I imagine was never used in home heating boilers, is a high pressure steam injector, used to move ambient temperature water at atmospheric pressure into a working locomotive steam boiler. And it has no moving parts. Here is a description of a few of them. They basically have three nozzles, in series, carefully designed.
http://www.catskillarchive.com/rrextra/chapt11.Html