Gorgon DOMGAS

Design and Detail of Filter Coalescer

CDMS was approached by Modular Engineering for the design and detail of a heavy wall (60 mm) coalescing filter vessel for Gorgon DOMGAS Pipeline Installation Project. The vessel was designed to filter natural gas at high pressure (over 17 MPa design pressure) as well as liquids.

Throughout the duration of the project CDMS worked closely with Modular Engineering, as well as the EPM, and consulted with various materials experts as required. CDMS started the design process with standard vessel design calculations and then checked customized components such as legs, nozzles and shell connections using Finite Element Analysis.

Custom in-house spread sheets were used to perform the pressure calculations accurately, and proprietary software was used to analyse the custom leg supports and nozzle junction stresses. During the design process the design conditions were altered by the client. CDMS incorporated these design changes economically with minimum impact on time and budget.

For further details on Pressure Vessel Design services provided please contact the CDMS team on (+61 8) 9421 9060 or email us at info@cdmsengineering.com.


Project Brief

Gorgon DOMGAS

Outcome

  • Completed drawings and calculations for the vessel per AS1210 – 2010
  • Client was satisfied with end result and the design has been successfully constructed and commissioned

Background

Modular Engineering is part of PECOFacet, a global coalescing, filtration and separation products and services company. Due to positive past experience, Modular Engineering engaged CDMS to execute the design and detail of a filter coalescer for its end user Chevron. The vessel was designed to filter natural gas at high pressure (over 17 MPa design pressure) as well as liquids. It consisted of a main vessel body with filtering elements and a sump for the liquids and weighed over 12 tonnes.

Project Objectives

CDMS was to design the filter vessel for domestic gas supply for the Gorgon DOMGAS Upstream project to AS1210 and Chevron project specifications. CDMS had to supply fabrication detail drawings suitable for construction of the vessel, incorporating testing and inspection requirements.

Challenges

Some of the challenges included pressure fatigue loading and custom leg supports. Because of the sump connections there was no room for saddle supports. Four legs had to be used but due to the high piping loads, standard structured members were not suitable, which meant custom legs were required.

Rolling of a relatively thick shell caused high fibre strain. This would preferably be restored by normalizing but the client expressed concerns about distortion of the shell. CDMS investigated alternative testing of as-rolled plates to see if post-weld heat treatment would satisfactorily restore material properties. After considering all possibilities it was decided that normalising would still be the best option and end caps were welded to the shell to protect it from deforming.

Custom forgings had to be made for the nozzles because of high piping loads and opening reinforcing of the high pressure vessel.

Our Approach

Throughout the duration of the project CDMS worked closely with Modular Engineering, as well as the EPM, and consulted with various materials experts as required. CDMS started the design process with standard vessel design calculations and then checked customized components such as legs, nozzles and shell connections using Finite Element Analysis.

Custom in-house spread sheets were used to perform the pressure calculations accurately, and proprietary software was used to analyse the custom leg supports and nozzle junction stresses.

During the design process the design conditions were altered by the client. CDMS incorporated these design changes economically with minimum impact on time and budget.