yarway valve explanation
yarway valve explanation
(OP)
Hi All
I have a question regarding Yarway Automatic Recycle Valves.
They all seem to say they are "flow sensing", but then seem to operate mainly on springs, while some have orifices.
can anyone succinctly answer how they sense flow, and not pressure related flow (as a set spring would do)
Thanks
Matthew
I have a question regarding Yarway Automatic Recycle Valves.
They all seem to say they are "flow sensing", but then seem to operate mainly on springs, while some have orifices.
can anyone succinctly answer how they sense flow, and not pressure related flow (as a set spring would do)
Thanks
Matthew





RE: yarway valve explanation
What did your local TYCO/Yarway representative tell you ?
-MJC
RE: yarway valve explanation
http://www.eng-tips.com/viewthread.cfm?qid=53164
thread408-53164: Pump Automatic Recirculation Valve
http://www
thread407-250882: automatic recirculation valve datasheet
http
RE: yarway valve explanation
Yes I did those searches first but they don't really tell me about the mechanics. I also printed out Yarway and Blackhall valve bumf from their websites. While I now understand mainly the way these work I still don't get how they are flow specified.
As for my local vendor, I haven't been in contact. They are already installed on an FPSO i'm working on and are subject to a Hazop action. Just wanted to understand for my sake
Cheers
Mat
RE: yarway valve explanation
Recycle flow is controlled by one or more orifices for the recycle stream. The control assembly is a combination of something like a "lift" check and an orifice stack. At no flow, the check is seated blocking flow to the user and the orifice stack is open to the recycle line. At low flows, the output is to the recycle line and perhaps back to the source. As flow increases, a point is reached where the check begins to lift, and there is flow to the user and to the recycle. Further increase in flow will further open the check and raise the orifice stack until flow to the recycle stops.
This arrangement is flow sensing only in that the recycle flow rate is determined by the orifice(s) and in that user flow is controlled by the flow required for lift force of the check. There is no continuous sensing of flow rate with a control function to start/stop recycle. This device will be affected by fluid and process properties.
This is my interpretation of available descriptions and drawings.
Bill Choate
RE: yarway valve explanation
One little phenomenon you need to be aware of, "any energy input into a system that is not converted to work will be converted to heat" these thing make great tea kettles if you're not careful and an excellent introduction to applied Thermo.
Hope this helps.