CLAYTON WALKER GASHOLDERS AT ALTRAD MOTHERWELL BRIDGE
The South American activities of the Clayton Walker Division (CWG) of Altrad Motherwell Bridge are represented and developed by KCE Consultoria Empresarial Ltda., focusing mainly in Gasholders for the Steel Industry.
Since the early 1990’s, KCE is present in the main steel industries, such as ArcelorMittal, CSN, Gerdau Açominas, Ternium Brasil and Argentina, Usiminas–Ipatinga and Cubatão, V&M Tubes, implementing new gasholders, supervising repairs and refurbishments, undertaking inspections, supplying equipment and materials, designing modernizations, doing studies for a safe and efficient operation of the storage of steel plant gases.
Altrad, through Motherwell Bridge’s Division CWG, is the only company in the World that designs, builds gasholders and develops technology for the main types of gasholders.
For more details, please access History of CWG besides all the links below related to each kind of gasholder.
CWG presents a reference list of 80 MAN type gasholders constructed or rebuilt in the last 92 years. There are gasholders of all sizes, from a small 7,075 m³ up to a large 226,400 m³, gasholder. 19 are larger than 100.000 m³ and 35 others have a capacity between 50,000 and 100,000 m³. To see the complete list please consult "Reference List - MAN | Internacional .
These gasholders have a polygonal shaped shell with columns and flanged plates, restrained by the roof structure and intermediate external platforms.. The gasholder’s floor is erected on a concrete base, supported by a foundation. Gas enters and exits through a common pipe, through the floor, is stored at a predetermined constant pressure and the volume variation is made possible the movement of an internal piston, along the shell. The stored gas is contained under the piston by a seal and atmospheric pressure is above the piston.
The two parts are isolated by a seal that uses oil or petroleum tar and rubbing bars are pressed against the shell to assure no leakage.
See details at "Sketches with seal details"
The operating pressure of the gas normally can be set at constant values from 170 mm w.g. to 1,700 mm w.g., depending on the client’s application and needs. To verify on how this gasholder functions, please consult the following animated presentation of the MAN in Operation:
CWG has a reference of over 230 Wiggins type gasholders, built during the past 70 years for use in steel plants, petrochemical, gas industry, for sewage and other gases. These are gasholders of all sizes, small and from 10,000 to 170,000 m³ capacity, all single lifts. To see the list of Wiggins gasholders designed and constructed with CWG design, please consult "Reference List - Wiggins | International" .
The Wiggins operating pressure can de designed for any value between 160 mm. w.g. and 1,200 mm. w.g. and is practically constant (± 10 mm w.g.). Its system assures complete tightness with the gas remaining below the piston. The space above the piston is totally ventilated by means of shell openings and a centre vent at the top of the gasholder. Operators and inspectors can enter this space with total safety without needing autonomous breathing systems, only as a mandatory precaution using portable gas detectors. Entrance and exit is made through any of the several shell doors, connected to the external staircase.
The synthetic seals are of three types; one for normal operations with BFG, natural gas, petrochemical or other gases, another is used when the gas temperatures are high, up to 80ºC (steel plant gas, for example) and the third type is for gases containing aggressive components, especially tar and BTX as is the case of Coke Oven Gases. The seal has a high resistance to abrasion, therefore, can operate with gases containing high particulate content. The seals have a 5 years’ guarantee, but the lifetime has proved to be much higher than this, depending on the gas more than 20 years. There are few components subject to wear as no consumables are required (grease, oil, water) and no components such as rollers, rubbing bars or rubber seals. Access is very easy and no external or internal elevators are required, but very little maintenance is required, only about 24 hours per year. This gasholder is of a much simpler design than other types and can operate with all types of gases. It is the only type that has the safety possibility of mechanically releasing 100% of the projected gas entrance volume rate.
CWG build much more than a 1.000 water sealed type gasholders during the 160 years of existence. These are gasholders of all sizes, with single lift and up to 5 or more lifts, column- or spiral guided. To verify a partial list of water sealed gasholders designed and erected please consult the "Reference List of Water Sealed Gasholders | International".
These are gasholders that operate with water seals between the lifts and the bottom tank. The operating pressures vary according to the client’s particular needs and to the number of lifts and operate with pressures from 170 mm. w.g. to 1.000 mm. w.g. Each gasholder operates at various pressure levels, because each lift operates at a different pressure.
During all these years, also due to the extremely numerous repairs, refurbishments, inspections, modernizations, performed as services, CWG consolidated much experience with this type gasholder. To see the list of services performed in form of maintenance, inspections, major refurbishments and repairs in Brazil and South America, please consult "Reference List of Maintenance, Inspections, Reforms and New Gasholders | Brazil and South America"
The spiral guided gasholders present a greater facility for maintenance activities, was developed by Clayton in the 1930 years and turned out to be the preferred version in the UK.
To see some photos of these gasholders, please consult the section "Gallery"
KLONNE GASHOLDERS
CWG accumulates a large experience in modernizing Klonne gasholders. These are gasholders that were preferentially directed to storage of Blast Furnace Gas but that haven’t been erected now for more than 20 years, except for two rebuilds in Japan.
Basically, the Klonne operates with a piston that moves inside a cylindrical tank. The seal has rubber/textile blocks and wooden components forming units that are continuously fed with lost grease to assure that the system remains tight. The seal assembly is pressed against the shell by means of internal counterweights. The lost grease accumulates under the piston inside a dam. The piston moves storing and balancing the gas variable demand and production. The external staircase, elevator and the platforms give access to the shell and roof, which is where the entrance can be made for inspections and maintenance. Ventilation is made through vents and windows in the higher part of the shell and through a centre ventilator on the roof. The piston levelling is obtained by numerous rollers on the upper and lower parts of the piston and these are pressed against the shell. As the years go by, this continuous pressure causes progressive distortions of the shell plates, that increase and reach values which the seal cannot accommodate anymore. From this moment on, the leaks are unavoidable and the gasholder must be reformed. CWG developed a unique system to eliminate this problem, preferably to be installed before the distortions reach this level. Basically, the piston is retrofitted with the Wiggins external counterweight system. This system levels the piston operation and removes most of the rollers’ pressure on the shell, therefore, strongly reducing the distortion progression. Basically, the system comprises external counterweights which run alongside the shell and are connected to the piston periphery by means of special ropes, each at two diametrically opposed points. This system’s efficiency has been repeatedly proven in various gasholders.
Photos of this type of gasholder can be seen at the section "Gallery".
CWG presents a reference list of 80 MAN type gasholders constructed or rebuilt in the last 92 years. There are gasholders of all sizes, from a small 7,075 m³ up to a large 226,400 m³, gasholder. 19 are larger than 100.000 m³ and 35 others have a capacity between 50,000 and 100,000 m³. To see the complete list please consult 
CWG has a reference of over 230 Wiggins type gasholders, built during the past 70 years for use in steel plants, petrochemical, gas industry, for sewage and other gases. These are gasholders of all sizes, small and from 10,000 to 170,000 m³ capacity, all single lifts. To see the list of Wiggins gasholders designed and constructed with CWG design, please consult 
CWG build much more than a 1.000 water sealed type gasholders during the 160 years of existence. These are gasholders of all sizes, with single lift and up to 5 or more lifts, column- or spiral guided. To verify a partial list of water sealed gasholders designed and erected please consult the 
CWG accumulates a large experience in modernizing Klonne gasholders. These are gasholders that were preferentially directed to storage of Blast Furnace Gas but that haven’t been erected now for more than 20 years, except for two rebuilds in Japan.