Pipe installation man hours issues.

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I have posted 2 attachements below. One from estimators piping man hours manual 5th addition and another from a contractor who priced some work for us.

The contactor got a value for a straight pipe run handling and erecting of 0.72 man hours per meter for a DN200 pipe. They also claim this came from the Estimators Piping Manhours Manual edition 3.

So we used the attached which a snap shot from Estimators Piping Manhours Manual edition.

For an 8 inch pipe they have 0.48 Man hours per foot. So if there is 3.28 feet in a meter then this will be 0.48 x 3.28 = 1.57 man hours per meter. This is double compared to the contractor who priced the work.

I hope I am doing something very stupid here as it is really a problem. The actual pipework feeds some chillers and it isnt the most easy to get to.

Could someone please give me their take on this?

http://files.engineering.com/getfil...4f7d-b08c-9148432cd982&file=pipe_anomoly2.JPG

http://files.engineering.com/getfil...-a095-d91deb683745&file=Man_hours_anomoly.png

 

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I forgot to say it is Schedule 40

 

[Mechanigenic]

You mention that it is Schedule 40 so if I am not mistaken you refer to wrong column on the chart. It should be 0.34 x 3.28 = 1.1152. It is still higher than the contractor, though.

 

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Ok yes you are right. I only found that out after I posted the original question. So there is nothing wrong with my calculations apart from that then? The contractor did these calculator on 34 km of pipe work. The increase they factored in from carbon steel to stainless is correct it's just these values are not correct and we can't understand why

 

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Still looking for an answer to this

 

[LittleInch]

Why do you care? contractor is clearly putting on a discount ( about 35%) either because he wants to win the job or realises that the estimates are excessive or maybe he just has faster workers.

You quote edition 5 for your list, you say he quotes edition 3?? If you use the same base document it might help....

Any of these generic estimating tools take the rough with the smooth so that some take a bit longer and some a bit less, but on average it takes that long. If there is a lot of pipe to do then maybe the average comes down as the workers get more efficient.

Who knows?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way