GFSA has recently designed and manufactured a Limpet Coil Vessel for a global supplier of speciality chemicals. The plant where the Limpet Coil Vessel is to be used produces fine chemicals operating under the top tier of the COMAH Regulations in the UK. The site’s primary focus is manufacturing actives and intermediates for the agro-chemical industry and pharmaceutical intermediates. Key technologies include chlorination, phosgenation, sodium dispersion and bromine chemistry.
The Limpet Coil Vessel consisted of a cylindrical vertical shell with standard torispherical dish on both ends with a semi-circular coil section wrapped around and welded to the bottom and sides of the pressure vessel. Steam was to be used to heat the 11,200 Litre vessel through the limpet coils to control chemical reactions inside. Although engineering drawings were supplied by the client, these needed to be updated and modified to meet the latest PD5500 Cat.2 and PED 2014/68/EU design codes. Design modifications were also needed to include a manway access cover.
The customer needed the Limpet Coil Vessel to be manufactured to a very tight deadline which required GFSA to plan and execute the complex manufacturing process meticulously and to modify procedures in order to meet the customer’s schedule. The modified procedure required welders to be qualified via a different process involving a GTAW (Tungsten Inert Gas) / MAG (Metal Active Gas) system plus a TIG root with MAG filler on the coil.