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Lang Factors for Cost Estimates
3

Lang Factors for Cost Estimates

Lang Factors for Cost Estimates

(OP)
Could anybody tell me where I could find Lang Factors?  I have read a lot about how they depend on the equipment, the industry and location, but I have not been able to find this actual information.  Are there tables or anything like that anywhere?  Any other sources?  (It is for a biopharmaceutical / lablike facility).

Thanks in advance for any info.

RE: Lang Factors for Cost Estimates

2
I will provide one or more references to the Lang Factor tomorrow. You may find some information on the Lang Factor in the Cost Estimating section of the Chemical Engineers' Handbook (Perry). In oil refining and petrochemicals we usually check a unit estimate my looking at the major equipment total cost and multiplying by a Lang Factor of 4 to 5 to get a Total Installed Cost.

HAZOP at www.curryhydrocarbons.ca

RE: Lang Factors for Cost Estimates

1.    Hans Lang, Cost Relationships in Preliminary Cost Estimation, Chem Eng, Oct 1947
2.    Hans Lang, Simplified Approach to Preliminary Cost Estimates, Chem Eng, June 1948
3.    Dysert L, Sharpen your Capital Cost Estimation Skills, Chem Eng, Oct 2001
4.    Cran J, Improved Factored Method vive better Preliminary Cost Estimates, Chem Eng, April 6, 1981.

The article by Cran is particularly helpful. He lists the following from Lang
For solid processing plant , total plant cost Major Equipment (ME) * 3.1
For solid/liquid ME*3.63
For fluid processing plants ME*4.74
Lang’s analysis included at least some offsite costs in his estimating factors.

HAZOP at www.curryhydrocarbons.ca

RE: Lang Factors for Cost Estimates

(OP)
Thanks owg - I'll check those out.  Please correct me if I am wrong assuming that Chem Eng is "Chemical Engineering"

RE: Lang Factors for Cost Estimates

Lang factors were produced long ago out of a study of some 14 plants only out of which three of them costing more than $2.5 million, small by modern standards. Lang factors, as well as the classification of the plant types as owg has well described, have been largely superceded and replaced with other cost estimating techniques, that include the selection of new more expensive metallurgies other than carbon steel, keeping, however, the factoring method but with factors adjusted down for higher equipment costs.

There are estimates that use factoring for individual pieces of equipment based on FOB costs plus an addition for transportation to the site. Others classify the plant sections into various categories such as battery limits (BL) that include site preparation as a miscellaneous item which depends also on the other sections, such as Storage Area, Utilities, Services, Indirect Costs, and Miscellaneous.

Because of the many uncertainties involved at the various stages of cost estimating, 15 to 50%, to cover for contingencies, are sometimes added, especially if the estimate is based on very preliminary flowsheets.

 

RE: Lang Factors for Cost Estimates

While the Lang factors are quite old, they are still useful for checking estimates of process plant construction costs. Lang predicted total plant construction cost based upon the delivered cost of plant equipment.

The factors are 3.1 for solids processing plants (a coal preparation plant for example)
3.63 for a solid-fluids process plant (a coal gasification plant would be an example)
4.74 for a fluids processing plant (such as an oil refinery).

The Lang factors should not be used for anything more than order-of-magnituse estimates but they are still reasonably good for that purpose, particularly when considering the fact that the AANSI Standard for order-of-magnitude estimates specifies that such estimates have an accuracy range of -30% to +50%.

RE: Lang Factors for Cost Estimates

Please can anyone tell me where I can find information on 1.Engineering Department Engineering Index (EDEI)
2. Engineering Department Materials Index (EDMI)
3.Engineering Department Labour Index (EDLI)
$.Engineering Department Plant Index (EDPI)
Reference Point 1940=100
Updating has to do with DRI database. I think ,though not sure, that DRI means DEvelopment Resource Institute

RE: Lang Factors for Cost Estimates

Sorry, I have not heard of any of those indices. Based on the spelling of the word labour it may be a UK based index. Google for once finds nothing on the subject.

HAZOP at www.curryhydrocarbons.ca

RE: Lang Factors for Cost Estimates

Please can anyone tell me where I can find information on 1.Engineering Department Engineering Index (EDEI)
2. Engineering Department Materials Index (EDMI)
3.Engineering Department Labour Index (EDLI)
$.Engineering Department Plant Index (EDPI)
Reference Point 1940=100
The DRI database is used in Updating the index. I think ,though not sure, that DRI means Development Resource Institute

RE: Lang Factors for Cost Estimates

ibolaoye:
It seems to me that you are looking in the area of cost information (or procedure for cost estimation or developing projects) of a production company, a main construction company or something similar.
Have a safe day
J.Alvarez

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