Re: Allowable external forces on Wellhead christmastree equipment.

From: <mapte@technip.com>
Date: Tue Jul 20 2004 - 09:21:00 EDT

Thanx Yudi,
We were also under same impression and doing this way for some time. However it was later discovered that API 6AF provides only the values against bore pressure and it does not explicitely say that the same can be used for the external allowable loads as well and this is exactly what I am looking at. (Clear mention of external allowable loads, API or any other coad / standard)

Have a nice day.
-Mandar.
This message comes from Mandar's desk.

                       yudi
                       <yudiveder@yahoo         To:     
PipingDesign@yahoogroups.com
                       .com>                    cc:
                                                Subject: Re: [PipingDesign]
Allowable external forces on Wellhead christmas      tree
                       20-07-04 01:16           equipment.
                       PM
                       Please respond
                       to PipingDesign

Dear all

Mandar, You have read API 6AF, in API 6AF mention that allowable load capacity of API flanges in relation with the bore pressure so If you have get result from piping stress report, you will obtain forces summary in 3 three coordinates that is Fx, Fy, Fz and this is external load that happen on API flanges (example in Wing Valve).

And from Piping stress report you have ensured that calculation have input external Load like wind, earthquake.

I think API 6AF enough for cover your topics

Regard's

Yudi

• mapte@technip.com wrote:
  >
  >
  >
  >
  > Hi,
  > We are working for an onshore oil extraction
  > project, including a number of
  > well head christmas trees and associated piping.
  > The question is as follows:
  > What are the allowable external forces (due to
  > connected piping) on the
  > flowing wing valve of the well head christmas tree
  > equipment.
  >
  > We looked in to API 6A, but it clearly states that
  > "The effects of external
  > loads (i.e. bending moments, tensions, etc.) on the
  > assembly of components
  > are not within the scope of this document".
  > API 6AF (Technical report on the capabilities of API
  > flanges under
  > combinations of load) and API 6AF1( Technical report
  > on temperature
  > derating on API flanges under combinations of
  > loading) talk about load
  > capacity of API flanges in relation with the bore
  > pressure. (No mention of
  > external loading.)
  >
  > Anybody who has faced a similar problem? What values
  > are used for allowable
  > loads? Is there any other standard / code that
  > covers this topic?
  >
  >
  > Have a nice day.
  > -Mandar.
  > This message comes from Mandar's desk.
  >
  >
  >
  >
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Yahoo! Groups Links Received on Tue Jul 20 09:21:00 2004