Does a slow-speed recip need to be grouted in?
Does a slow-speed recip need to be grouted in?
(OP)
Hi guys. Looking for opinions here... In your opinion, does a slow-speed recip pump need to be grouted in?
Pump in question is a Gaso 1753 duplex piston pump. Operating speed is about 76 spm, 900 rpm motor, belt drive. The pump and motor are mounted on a pretty beefy structural steel skid. Thanks! Pete
Pump in question is a Gaso 1753 duplex piston pump. Operating speed is about 76 spm, 900 rpm motor, belt drive. The pump and motor are mounted on a pretty beefy structural steel skid. Thanks! Pete





RE: Does a slow-speed recip need to be grouted in?
The grouting is realted to the levelling requirements of that pump and perhaps, filling up the gaps under the baseplate when anchoring the assembly.
It also helps to stabilise the equipment on a flat surface generated by grouting (in association with bolting down).
Then again, if there is no concern with possible movement of the unanchored pump assembly, then the grouting is useless.
cheers,
gr2vessels
RE: Does a slow-speed recip need to be grouted in?
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RE: Does a slow-speed recip need to be grouted in?
Good pulsation dampers are a must too.
RE: Does a slow-speed recip need to be grouted in?
I do not know the natural freq of the pump + baseplate. The foundation is designed with mass > 5x the mass of pump + baseplate and uses embedded anchor bolts. Once the skid is set, bolted down and grouted, I should be OK in the vibration dept. I have pulsation dampeners on both suction and discharge.
Thanks! Pete
RE: Does a slow-speed recip need to be grouted in?
Some thoughts:
I would think a recip demands more care to the foundation than a pump.
A large foundation accomplishes nothing if the baseplate is not securely attached.
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RE: Does a slow-speed recip need to be grouted in?
You are correct - a recip demands more of a foundation. Hence the 5x mass requirement. This is a slow-speed pump, so the requirements are not as rigid as, say, a 450 rpm gas compressor. Thanks!
RE: Does a slow-speed recip need to be grouted in?
http://virtualpipeline.spaces.msn.com
RE: Does a slow-speed recip need to be grouted in?
It wasn't the speed of the motor that was the problem. It was the forces generated as the pump very rapidly accelerated the fluid in the pipe up to full speed, and just as quickly (probably quicker) brought that fluid to a hault. As you are looking at a reciprocating pump here, if it is on DOL startup, I would ensure it is grouted in and the grout has gone off before commissioning it. If it is on soft start or VSD, you will probably be okay without the grout.
This force produced during the acceleration of the fluid by a positive displacement pump is large compared with the force generated by a centrifugal pump, which is simply the closed valve head of the pump.
RE: Does a slow-speed recip need to be grouted in?
http://virtualpipeline.spaces.msn.com
RE: Does a slow-speed recip need to be grouted in?
I would certainly recommend that all machinery be properly installed, levelled and grouted as I am sure the manufacturer recommends.
RE: Does a slow-speed recip need to be grouted in?
Also, an unfilled skid will quickly collect dirt, water, plastic cups, etc.
RE: Does a slow-speed recip need to be grouted in?
About the only reason I could see for filling in the entire skid with grout was to keep out trash. The operator has to have something to do...
RE: Does a slow-speed recip need to be grouted in?
You'll dig two troughs in the top of the foundation just under the skid I-beams will be and fill them back to approx the original level? Or trim off the whole top of the foundation flat(laitence or whatever they call it) and just build two troughs of grout on top?
The second option sounds kind of ugly. The first option sounds like you've got no support on the sides of the grout. Isn't there a poisson's ratio effect going on where the grout is stiffer vertically if it can't expand horizontally?
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RE: Does a slow-speed recip need to be grouted in?
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