pumps and vibration isolation

[NordicDesigner]

Hi,
Does anybody have any good pictures of what can happen in a boiler rooom when you install large hvac pumps and don't use any vibration isolation?
The job I'm working on has pumps up to 75HP and 1,800gpm and the vibration isolation material (spribngs, etc) were "value-engineered" out, so the pumps are sitting directly on the concrete housekeeping pads. This didn't concern me too much until the chief estimator at my job told me that the flexible connectors were also "value-engineered" out. I don't want to be responsible for what could happen after this system is installed and have told everybody this, but if somebody has some good pics and I can show them how costly this could end up being, I might be able to convince them to let me install the braided steel, flexible connections at the very least. By the way, the engineer who originally did the job doesn't want to get involved any more than he has to, so it's no use asking him for direction.
Thanks.

 

[ChasBean1]

Might as well engineer out dynamic balancing too, right? Sounds like someone's not thinking right... There's a forum called "Pump Engineering" also - did you also post there? There might be some pretty good 'pump heads' over there that don't check in here. I'd be interested to see responses to this thread.

 

[lilliput1]

Refer to ASHRAE 2003 HVAC Applications Handbook Table 42, page 47.42 for Selection Guide for Vibration Isolation. Note requirement for vibration isolation is more stringent if the pumps are on elevated floors and more so with larger dimension of the floor span between columns. See also page 47.41 for discussion on Resilient Pipe Hangers and supports and Flexible Pipe Connectors.

Be careful if there are two position control valves in the line. They can generate vibration in the piping if located far from anchor points or equipment anchored to floor.

 

[quark]

75HP, 1800gpm pump may not be a big one IMHO. If it's a 1500rpm pump then problems may not be severe. We had a battery of such pumps running smoothly without any problem.
Get them properly balanced, as suggested by CB and also have them properly aligned.


Check this thread407-102681 for a discussion on flexible connections.

Regards,

 

[SAK9]

Further to what Quark has said,it is not a must to have vibration isolators and flexible houses for pumps.IF you look at the oil and gas industry all pumps are bolted to the pads without any vibration isolation and thay do not use any flexible joints for the same reason.The pump nozzles should be capable of withstanding all loads on them.This is dealthwith very clearly in API610 the standard for pumps in the refining industry.Noise from vibration is an issue in occupied buildings and most engineers take the easy way out by having vibration isolators and flexible hoses.If your plant room is in the basement, vibration may not be an issue .So every problem needs to be looked at from different angles rather than applying universal solutions.