Are you following the 10x rule on the inlet to the pump?? Cavitation is due to low pressure at inlet but it can happen due to process flow design as well as size.
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what is the 10x rule?
i dont think the issue is vapor in the process flow but the gas expanding into vapor in the pump. from what i understand it shouldn’t really be having cavitation issues with the conditions its under but i can’t what come up with any other reason the seals on the pump would go from functioning to not in less than 24 hours of run time
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Are you running the pump dry at all?
That can cause damage to the seals also
I really dont think it has to do with cavitation, what pump are you using? Ill look up the recommendation for the inlet size im sure its alot smaller then 1.5"
no the pump is flooded with solution before i fire it up. cat pump model 3CP1211CS.0110
You need to increase the feed pressure or reduce your pump speed and concentrate flow.
feed pressure doesn’t seem to be effecting it much if at all. I didn’t think I was having the issue when I reduced the pump speed but then my seals failed
Inlet should be 10x diameter straight before entering the pump inlet. So if you had 1.5”, it would be 15”. Since you’re dealing with hydrocarbon’s, I wouldn’t think this would be the issue but something to keep in mind. Sounds like the pump could be running dry as well.
ok well I’m not running that much hose between the tank and the skid, if I continue to have this issue ill try this. also I should note that the actual inlet size on the pump is 3/4" but I’ve got my feed tank connected to 6’ length of 1.5" hose that is reduced down to the 3/4" inlet
After your run is done youre keeping the pump filled with solvent? Its definitely not cavitation as weve ran way smaller then 1.5" tubing at way lower pressures on our inlet and never had a problem
we ran a test on clean gas to flush the membrane and make sure everything was running properly. then left the skid filled with clean tane. next day pumped in solution got it permeating couldn’t go above 18 hz without the pump starting to knock which joel mentioned was a sign of cavitation. ran for a little while before the pump started making a terrible sound so i shut it off drained the system and pulled the pump apart(i noticed the drive shift on the pump had scratches on it) couldnt find anything causing the issue. when i put it back together the noise was gone but the pump wouldn’t move any solution so i assumed the seal failed
Where did you get the pump from? Joel?
Did you build this skid yourself or did you buy it already put together
Im asking because Scratches on the shaft to me makes it sound like maybe the pump wasnt fully assembled right and something came loose inside. There should never be any kind of markings on the crank shaft or piston rods, they should never touch the sides and if it was knocking like that i think a bolt holding the rod onto the shaft could have loosened and cause the rod to hit the inside casing.
whole skid is from Joel, when I opened it there wasn’t anything inside to “catch” on it and if anything had fallen in and back out of the housing i cant imagine I would miss that so I think it must’ve at least come to us with that damage
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Check your dms when you have a minute
you should have a length of straight run pipe that is 5-10x the length of the diameter of that pipe inbetween any obstruction (tee, elbow, ball valve) and the inlet of the pump
New extraction methods on the horizon will make membranes obsolete
Yust saying !
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Cant wait for it to debut
Care to elaborate?
Electrostatic? 
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Really looking forward to hearing about it in the future. Hear tell through the grapevine sounds pretty damn interesting!