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Centerline supported pump? 1
- Thread starter hemvig
- Start date
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1
- #3
hemvig,
Centerline supported simply means that the pump casing is supported at the rotating assembly centerline as opposed to being supported at a point somewhere lower on the case.
In API type services where elevated temperatures are routine, this allows thermal expansion growth of the case (or barrel here) to be symmetric from the shaft centerline outwards.
If the case is supported other than at shaft centerline, then case centerline will move from its position during expansion, and can cause serious misalignment issues with driver (which is not heating and moving at same rate as pump).
Centerline supported simply means that the pump casing is supported at the rotating assembly centerline as opposed to being supported at a point somewhere lower on the case.
In API type services where elevated temperatures are routine, this allows thermal expansion growth of the case (or barrel here) to be symmetric from the shaft centerline outwards.
If the case is supported other than at shaft centerline, then case centerline will move from its position during expansion, and can cause serious misalignment issues with driver (which is not heating and moving at same rate as pump).
- Thread starter
- #4
Pumpsonly:
Thanks for the reply on BB5 pumps. I know how the centerline mounted looks like on BB5, but just wanted to get more information.
Also the vendor on the BB5 pumps said it is possible to have a side side arrangement. Does anybody know if there are any drawbacks in having a side side arrangment for a BB5 pump.
DubMac: Thanks for the reply. Please provide your thoughts on the Side/Side BB5 barrel pump.
Thanks in advance for the replies.
Thanks for the reply on BB5 pumps. I know how the centerline mounted looks like on BB5, but just wanted to get more information.
Also the vendor on the BB5 pumps said it is possible to have a side side arrangement. Does anybody know if there are any drawbacks in having a side side arrangment for a BB5 pump.
DubMac: Thanks for the reply. Please provide your thoughts on the Side/Side BB5 barrel pump.
Thanks in advance for the replies.
hemvig,
It could be possible with either suction or discharge on side connection depends on the number of stages and construction.
Pump supports are usually place vertically in line with the nozzles to provide the optimum pipe load support. Moving it away will compromise the stability.
It could be possible with either suction or discharge on side connection depends on the number of stages and construction.
Pump supports are usually place vertically in line with the nozzles to provide the optimum pipe load support. Moving it away will compromise the stability.
hemvig,
Familiar mostly with top/top and bottom/bottom arrangements of nozzles. If Sulzer makes a side/top like in Pumpsonly's PDF, then it must be fine, they are as good as it gets.
There shouldn't be any inherent problem with side/side (especially in a barrel), if it was designed that way by a reputable manufacturer. They would take into account the non-symetric loads on the barrel; there's usually plenty of meat there to offset any static unbalance.
The question I would ask you is, "Why are you looikng to design the pump nozzles around your piping design???" Probably a space constraint, but many dangers are lurking.
Many times when pumps are designed into a cobweb of piping and other space constraints, the pump ends up being a "pipe hanger". Though not a part of the design, somewhere along the line in these situations, someone fudges a bit and you end up with piping flange an inch or so out of line with pump nozzle. Then a spud wrench with a cheater pipe and a big guy jumping up and down on it, is used to "align" the flange holes, pump is bolted up and everything looks fine. Then nobody can figure out why the pump can't keep seals in it and is always out of alignment.
May not have anything to do with your particular scenario, but keep in mind that piping should be designed around the pump.
Familiar mostly with top/top and bottom/bottom arrangements of nozzles. If Sulzer makes a side/top like in Pumpsonly's PDF, then it must be fine, they are as good as it gets.
There shouldn't be any inherent problem with side/side (especially in a barrel), if it was designed that way by a reputable manufacturer. They would take into account the non-symetric loads on the barrel; there's usually plenty of meat there to offset any static unbalance.
The question I would ask you is, "Why are you looikng to design the pump nozzles around your piping design???" Probably a space constraint, but many dangers are lurking.
Many times when pumps are designed into a cobweb of piping and other space constraints, the pump ends up being a "pipe hanger". Though not a part of the design, somewhere along the line in these situations, someone fudges a bit and you end up with piping flange an inch or so out of line with pump nozzle. Then a spud wrench with a cheater pipe and a big guy jumping up and down on it, is used to "align" the flange holes, pump is bolted up and everything looks fine. Then nobody can figure out why the pump can't keep seals in it and is always out of alignment.
May not have anything to do with your particular scenario, but keep in mind that piping should be designed around the pump.
racookpe1978
Nuclear
Oh - never fear - Pipe is always "designed around a pump".
But pipe is almost always installed and welded up after the pump is in place ... So lousy alignments are "made up" by big guys and chainfalls moving the (not really flexible) pipe over sideways and up next to the stationary pump nozzle. "Obviously" the pump flange is never distorted by moving the pipe flange into place. (Har, har.)
Of course, it looks nice and straight when nightshift fabrication ends and dayshift begins testing..........
But pipe is almost always installed and welded up after the pump is in place ... So lousy alignments are "made up" by big guys and chainfalls moving the (not really flexible) pipe over sideways and up next to the stationary pump nozzle. "Obviously" the pump flange is never distorted by moving the pipe flange into place. (Har, har.)
Of course, it looks nice and straight when nightshift fabrication ends and dayshift begins testing..........
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