Recycle Valve
Recycle Valve
(OP)
I'm adding a recycle valve to keep a pump from shutting down on low flow. The following valve was recommended for the conditions listed below also:
3" 300# RF FISHER 667-ET, WCB BODY, 3-7/16" FULL PORT CAV III 1-STAGE TRIM, SST PLUG & SEAT W/ STELLITED SEAT AREA, SIZE 45 FAIL CLOSE ACT., 13-30# BENCH SET. PROCESS WILL FLOW DOWN OVER SEAT
P1 = 254 psig
P2 = 8.5 psig
T = 170*F
Q = 1000 gpm (Produced Water)
I was planning on using small bore pipe (3") to take some of the pressure drop. What is the maximum velocity you want going through 3" Sch 40 316 SS pipe?
3" 300# RF FISHER 667-ET, WCB BODY, 3-7/16" FULL PORT CAV III 1-STAGE TRIM, SST PLUG & SEAT W/ STELLITED SEAT AREA, SIZE 45 FAIL CLOSE ACT., 13-30# BENCH SET. PROCESS WILL FLOW DOWN OVER SEAT
P1 = 254 psig
P2 = 8.5 psig
T = 170*F
Q = 1000 gpm (Produced Water)
I was planning on using small bore pipe (3") to take some of the pressure drop. What is the maximum velocity you want going through 3" Sch 40 316 SS pipe?





RE: Recycle Valve
On the other hand, you can determine the state of choke flow on the three (3) inch schedule 40 pipe and reduce that to a level acceptable by the pump.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: Recycle Valve
Going the Big Inch!![[worm] worm](https://www.tipmaster.com/images/worm.gif)
http://virtualpipeline.spaces.msn.com
RE: Recycle Valve
IF the water is clean, I might push 20 ft/sec but why? The control valve is going to have to take the majority of this drop and this is going to be a severe service valve no matter what.
If these are produced water pumps, I would recommend starting with the minimum flow from the manufacturer, I suspect they could be in the range of 30% to 40% of BEP to avoid suction recirculation problems. You can always decide to set the minimum flow lower if you like but start with the manufacturer's recommendations, minimum flows have increased significantly over when I first started in this business.
RE: Recycle Valve
The 30-40% min pump flows will not heat nearly as much as lower flows would and you'll get much longer op time, but still won't help sand through the valve.
I would say any recycle flows should not be "normal operation", in the sense that recycling should be used for starting and shutting down the pump... ONLY.
Going the Big Inch!![[worm] worm](https://www.tipmaster.com/images/worm.gif)
http://virtualpipeline.spaces.msn.com