Baseplate & Soleplate Design
Baseplate & Soleplate Design
(OP)
Hi,
I have been reading through API 686, 610, 685, etc. and cannot seam to find any specification on baseplate/soleplate thickness. There is an appendix in 610 and 685 (Appendix M) on plan dimensions, but nowhere does it mention requirements for thickness. The reason I ask is, from a commercial Quality stand-point, what is stopping an EPC from specifying, say, a 1/8" baseplate for a 5000 HP pump? I understand that would be practically ridiculous, but in the commercial world everything needs to be tied to contractual documentation, and I'm sure crazier things have been done...
I have been reading through API 686, 610, 685, etc. and cannot seam to find any specification on baseplate/soleplate thickness. There is an appendix in 610 and 685 (Appendix M) on plan dimensions, but nowhere does it mention requirements for thickness. The reason I ask is, from a commercial Quality stand-point, what is stopping an EPC from specifying, say, a 1/8" baseplate for a 5000 HP pump? I understand that would be practically ridiculous, but in the commercial world everything needs to be tied to contractual documentation, and I'm sure crazier things have been done...





RE: Baseplate & Soleplate Design
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Baseplate & Soleplate Design
There are simply too many pumps, motors, sizes etc for anyone tyo specifiy a minimum thickness so the performence spec is the way to go.
If the EPC specified that and the pump base plate flexed, then he would be liable for getting another one which didn't flex. I can't see an EPC contractor doing that - he would simply leave that to the pump vendor, agina whocse interest is not in supplying somehting which flexes when it shouldn't.
Is this a specific query or just a "what if"??
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Baseplate & Soleplate Design
RE: Baseplate & Soleplate Design
Also at some point you need to lift this pump and motor into place and also test it without any grout. 1/16 plate won't let you do any of that.
Is there something behind this?? You seem very keen to try and use a very thin plate....
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Baseplate & Soleplate Design
After thinking about this more, I think I have come to a conclusion. The baseplate needs to be designed to a certain thickness for three main reasons: bench testing (FAT), transportation, and so that the grout can achieve full contact underneath the plate. The last one is important because if the baseplate is very thin, it makes it very difficult to ensure full grout contact all around the underside of the plate. API 686 also says that the grout should be poured halfway up the baseplate. I am assuming this is so full underside contact is ensured.
Thanks for the input everyone. Still open to any comments!
RE: Baseplate & Soleplate Design
I think you have been confusion others by missing up the term baseplate and sole plate. And you actually meant sole plate for vertical pumps in this posting. Please refer to Fig 33 of API 610 -10th edition. Sorry That is the latest I am having.Baseplate is referred to horizontal pump and you can not make a 1/8" baseplate.
The purpose of the sole plate, other than to provide a level machined surface for mounting the vertical pump discharge head , it must be able to withstand the moment and forces imposed on it by the piping strain if any via the discharge head.
If some one can design or make a 1/8"thick sole and have enough strength to hold the stud bolts for mounting the pump to withstand the piping forces and moment..then it is acceptable.
RE: Baseplate & Soleplate Design
1) compression loads to as uniformly as possible distribute the pump's maximum load (short circuit torque) to the grout. 1/2 the full width of the base plate is usually designed as a cantilever beam, so bending at the root of the beam is limited to 2/3 of the steel's yield strength.
2) Tension loads from the bolts when under short circuit torque load. The plate again being designed as a cantilever beam, but with a point load at the bolt location. The bending and shear loads being resisted by the cross section of the base plate at its root.
Try to find a copy of "Design of Welded Structures" by Blodgett. Lots of good typical examples of how to design welded connections for beams, columns, connections and baseplates in general.
Independent events are seldomly independent.
RE: Baseplate & Soleplate Design
Sometimes when I re-read things with a cold eye I see them differently (or maybe I should say correctly). I understand what you are saying about the baseplate being sufficiently strong on it's own now. Also, the manufacturer will have to perform all the FAT tests on a test bench at the shop. At that point there is no grout, so obviously it has to be strong enough without the grout.