Tanks, Thickeners & Clarifiers

CDMS Consulting Engineers (CDMS) has a team that is highly experienced in the specification, design and detailing of tanks, thickeners, and clarifiers. Working to an international quality management standard (ISO 9001-2015) we are able to offer our services to the highest level of quality control which can be difficult to find elsewhere. All engineering designs are delivered with high regard for Australian Standards and meeting compliance requirements.

Bulk Storage Tanks

Over the years CDMS has had experience designing and detailing many bulk storage tanks for energy generation, hydrocarbon processing, mineral processing, and fuel and water storage purposes. We can design to a number of standards, such as AS 1692, API 1620, and API 650 with diameters ranging from 1.5 to over 50 metres in diameter. CDMS has an in-depth understanding of tank design across all aspects, such as materials selection requirements, cyclonic wind loading, earthquake design, roof design, footing design, and design of the hold-down chairs. Our office has developed a number of in-house programs to create smart, efficient designs. Additionally we have a large amount of experience with repairs of tanks to API 653 code and have assisted in the design and detailing of jacking a 29 meter diameter tank in order to remove and replace the corroded floor plate.

Custom Tank Design

CDMS has extensive experience in the design of onshore, offshore, and transportable storage tanks, for both traditional horizontal and vertical cylindrical designs as well as unique custom geometry including square and obround, self bunded and container tanks. Building on our tank design expertise, CDMS has the capability to custom design almost any geometry to suit a client’s specific storage requirements, in complete compliance with current API 650, API 620, and AS 1692 design standards, as well as meet the requirements of AS 1940 for strict operator specifications. The highly skilled team at CDMS can also audit and review existing tank installations for code compliance and provide recommendations for retrofits, repairs (tank jacking) or complete replacement. CDMS will ensure operators are in compliance with the latest industry standards and safe storage procedures.

CDMS can design custom tank storage units around existing site structures, layouts or spacing limitations. We will consider all civil and structural design of earth, lining and penetration design, capacity calculations, as well as all attached mechanical equipment loads, including access platforms, spiral staircases as well as local pipe stress analysis on connecting nozzle flanges.

CDMS uses advanced Finite Element Analysis (FEA) software to design custom shaped tanks installed offshore subject to hydrostatic pressure, roof loads and motion accelerations. FEA is employed by specialist engineers to verify all external loadings on tank supports, shell and nozzle weld preparations, footings, and pipe supports to prove compliant with the required design standards. FEA modelling is used to efficiently optimize the size and number of stiffeners, reduce shell wall thickness, and select suitable materials for different storage applications. Once the engineering design is complete CDMS can produce shop detail level drawings used during fabrication, construction, and commissioning.

Thickeners & Clarifiers

CDMS have designed and detailed a number of thickeners and clarifiers over the years, ranging from low shear to high shear designs and from 6 to 90 metres in diameter. We have experience working in collaboration with process engineers in conceptual stages to provide preliminary design to reduce overall lead times for these items. CDMS can design all aspects of the clarifiers/thickeners such as the underside structural supports, the cone in either a petal plate configuration or to API 620 with a flat cone, the raking arms, overflow launders, and full span and pier type bridges. CDMS uses Finite Element Analysis (FEA) where appropriate to determine the most effective design to create an efficient and safe structure. We have had experience in modularising units for transport and erection to ensure time and money is saved on site.

Repairs & Alterations

CDMS has significant experience working to API 653 for the repair and alteration of API 650 storage tanks. Such operations include modifications to roof mounted structures, nozzle relocations and new nozzle inclusions, floating suctions, openings for maintenance vehicles, roof openings and equipment installation.

We can assess settlement and floor bulging issues in line with API 653 acceptable limits as well as provide advanced computational analysis to assess shell and annular plate bending which incorporates subgrade interactions where required, and fatigue analysis of floor plate bulges exceeding API 653 limits to assess grout injection or replacement requirements.

CDMS has designed numerous tank jacking systems for floor replacement operations, as well as associated reinforcement checks of nozzles when ground offset is reduced below API 653 limits. Roof and strake plate lifting studies are also commonly requested for refurbishment and demolition operations.

We can provide analysis for shell plate lamination and localised thinning due to corrosion or erosion. Working closely with local fibre reinforced plastic (FRP) experts we can provide unique tank remediation options for FRP patching and wrapping of in-service tanks and piping.

CDMS can provide safety and code compliance reviews of tank access systems, as well as design any necessary upgrades, such as fall arrest anchors (or nozzle load checks), guard railing upgrades, stair and ladder upgrades, access walkways between tanks and secondary egress systems.