×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Lang / Hand factors are based on purch. or delivered equipement cost?

Lang / Hand factors are based on purch. or delivered equipement cost?

Lang / Hand factors are based on purch. or delivered equipement cost?

(OP)
Dear all,

Can you please provide confirmation whether the Lang, the Hand and the Wroth factors for preparing cost estimates are based on purchased or on delivered equipment?

Various sources suggest differently:
+James R. Couper suggests in Perry's Chemical Engineers' Handbook ed. 8 that Lang and Hand start with purchased equipment cost while Wroth starts with delivered equipment cost. Note: in the same book, on the same page authors states Lang is based on delivered equipment cost
+ same author James R. Couper suggests in Process Engineering Economics that Lang is based on delivered equipment; Hand is based on purchased equipment costs; later the author summarizes that Lang and Hand methods start with delivered equipment costs, but the Wroth method begins with purchased costs
+ Max S. Peters and Klaus D. Timmerhaus suggest in Plant Design and Economics for Chemical Engineers ed. 5 that Lang is based on delivered equipment cost
+ Gavin Towler / Ray Sinnott suggest in Chemical Engineering Design Principles, Practice and Economics of Plant and Process Design suggests that Lang is based on purchased equipment cost
+ Harry Silla in Chemical Process Engineering Design and Economics suggests that Lang is based on delivered while Hand factor is based on purchased equipment cost

Can you please provide additional information?
If anyone has access to the original publications by Lang, Hand or Wroth, please let me know.

Thank you in advance.

Best regards,
Stan

RE: Lang / Hand factors are based on purch. or delivered equipement cost?

Zaigrata,

you are talking about estimates in the +/-30% range. Don't try to be too accurate on items with small effects on the final number.

The article "Making Sense of your Project Cost Estimate" by J.C. Lagace, CHEMICAL ENGINEERING Magazine of August 2006 might be helpful.

Kind Regards,
hahor

RE: Lang / Hand factors are based on purch. or delivered equipement cost?

When I have seen the estimates used, they were stated as delivered, Gulf Coast only.   Anything outside of the US would cost more for shipping so that would have to be factored in.  Hahor is right that you are not going to get very close with the Lang factors.   Most of the time you don't get that close with an initial bid.  The devil is always in the details of the projects that come up later anyway.

Regards
StoneCold

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources