What about using a regenerative turbine pump? I've used them in chemical plants, they're ideal for high head very low flow applications. I've used them down to 0.5m3hr flowrates. I think Sundyne market them under the Caster brand.
Hi, Ive spliced orings in static applications using superglue as an adhesive. Also bind the finished spliced joint with ptfe thread tape to isolate the process medium from the joint.
regards
John
Tmoose
Double row angular contact bearings with filling slots are very common. They are a high load capacity bearing but only in one direction. You have to be sure of the direction of thrust in order to take advantage of it. I have changed out this type of bearing on some other pumps...
Thanks for the replies,
The impeller has 5 vanes. Vibes were strongest at the drive end and were actually audible. Reversing the orientation of the double row angular contact bearing cured the problem (thrust forces had been running against the filling slot, but no actual visible damage when...
Hi, I'm a vibration amateur, so hopefully someone can advise. The problem was high vibes at 14X running speed on a recently overhauled centrifugal pump. Vibes were at the drive end, which is fitted with a slot filled double row angular contact bearing.
The pump runs at 3000rpm
Vibes were at 14X...
I think he refers to recirculation within and around the impeller vanes due to operating at low flow or high flow conditions. This is due to the impeller vane angles being designed around a flow rate envelope. Operating outside of these flowrates produces a stall condition similar to that...
Hi, i've used Warman 3/2 CAH rubber lined pumps with rubber lined impellers successfully on Water with Sodium Thiocyanate and Volcanic Ash duty. One thing to bear in mind when using rubber lined impellers is that they can't be trimmed. So will require either a belt drive or vfd to achieve duty...
Longitudinal marks on journal look very much like grinding wheel marking, possibly from "blinded" wheel or excessive load applied to wheel. Has the journal been refinished at some point?
regards
John
Hi, had a similar problem pumping vacuum degassed acrylic dope at 40,000Cp using Mono PC pumps. Turned out it was the mechanical seal allowing ingress of air. Had to alter pipe work so suction became discharge and change pump rotation. Net effect was that mech seal was then at high pressure end...
Seen this kind of thing before on magdrives, several answers listed already. My experience included reduced magnetism due to the use of stainless steel containment cans. Low flow conditions leading to high temperature at the inner magnetic rotor (below a certain temperature the magnetic strength...
Hi, had similar recent problems on recently overhauled David Brown multistage crude oil charge pumps. Problem seems to be skidding row of balls in double row angular contact bearing and also wear of the pressed steel bearing cage (SKF Explorer bearing)See this article for more explanation...
Sounds like vibration loosening the nut off, especially if the shaft subsequently snapped at the thread relief. Any cavitation or out of balance? try a vibe check whilst the pumps are running.
Our operators are requesting guidance on acceptable mechanical seal leakage rates (I know this seems a contradiction in terms!)Typically interested in API hydrocarbon pumps. I am aware that this has implications with COMAH DSEAR and environmental considerations etc. But one mans drip is another...
Plenty of food for thought from the replies. We are presently around the 44 month mark. Our problem is that we cannot compare with other refineries in our group because they use different criteria. We count failures as direct interventions caused because the pump fails to function as designed...
