Increasing regulation focuses on chemical storage tank design

Paul Boughton

Suppliers of chemical storage tanks and their associated equipment have to keep sharply focused on new and impending legislation. Sean Ottewell reports.

Chem Resist Europe says it has the in-house capability of producing the world's largest corrosion resistant all-thermoplastic spiral-wound vertical cylindrical chemical storage tanks and vessels. Manufactured in polypropylene and high density polyethylene with diameters up to four metres, all of its thermoplastic chemical storage tanks and vessels provide a true alternative to glass fibre reinforced (GRP) and traditional lined metal vessels for the storage and processing of corrosive solutions.

The company's chemical storage tanks and vessels are designed to European standard EN 12573:2000 which is adopted across the EU and offers engineers the ability to specify construction to a pan-European standard. Production of spiral wound tanks and vessels both in the UK and Czech Republic means that the company can offer supply to customers' plants both in the UK and continental Europe.

Chem Resist European's latest contract completion is for Holchem Laboratories, one of the UK's foremost detergent and disinfectant manufacturers. Chem Resist was chosen for the design, manufacture, installation and commissioning of a complete storage and mixing plant for the majority of the company's high-volume cleansing products. The new system gives Holchem increased capacity, allowing them to cope more efficiently with high-demand spikes at particular times of the year.

Another major manufacturer, UBH International, has conducted a whole life cost analysis that compares its own and other tanks. The analysis suggests that savings with its own products are in the region of 30 per cent. This, says the company, is down to general resilience of design, use of standard materials, and visibility of/access to structural elements which together ensure easy assessment and repair. Its tanks are being used worldwide to handle materials as diverse as hazardous and non-hazardous chemicals, ultra-high purity liquids and gases, cryogenic gases, LPG, hazardous waste and food-grade products.

"As a manufacturer of bespoke products for an immense range of specialist applications, UBH International consults closely with its customers in order to produce carefully tailored solutions," says the company.

The company operates a ISO 9001:2000 quality management system and also holds ASME U and R stamps for its manufacture and repair work.Also, in the interests of safety, efficiency and the environment, UBH seeks to promote, where possible, the eco-friendly concept of inter-modal transport, which allows the swift, secure and economical transfer of tanks between road, rail and container vessel (Fig.1).

The Tank Connection Affiliate Group (TCAG) is an integrated family of companies that specialize in liquid and dry bulk storage applications worldwide. Unlike tank suppliers that offer a single choice in tank construction, TC says it is the only tank manufacturer that designs, fabricates and installs all four types of steel storage tanks including bolted RTP (rolled, tapered panel), field-weld, shop-weld and hybrid tank construction.

TCAG storage products and services not only command high quality ratings in the industry, but its process operations are vertically integrated, which promotes its global position as a competitive price leader. Starting with steel procurement at the mill and finishing with construction services in the field, all value-added design, manufacturing, project management, system integration and field installation services are performed by TC personnel.

TCAG specialises in extra-large storage tanks, custom engineered truck and rail drive-through designs and integrated systems. It also offers powder-on-powder coatings and a turnkey installation service.

All ammonia diffusion tanks from BH Tank are provided with Auto CAD submittals to allow for easy integration into customers' project designs and faster fabrication turn-around. Typical tank capacities range from 1000 to 100,000 gallons.

The company has specialised in water storage tanks since 1935 and its integrated services include initial consultation, design submittals, tank fabrication, coating systems, accessories (such as sparger tubes, level controls and gauges, ladders, platforms, anchoring devices, inspection and maintenance manways), foundation design and installation, tank padding, tank delivery and installation. Piping and valves to the tank are provided by the mechanical or refrigeration contractor.

Chemical Process Solutions (CPS) designs, manufactures and installs thermoplastic chemical storage tanks to BSEN12573:2000 and BS4494.1987. These include helically wound polypropylene chemical storage tanks and high density polyethylene chemical storage tanks up to 3.5m diameter and capacities up to 80m2. Also butt welded polypropylene sheet tanks and high density polyethylene sheet tanks up to a 20,000 litre capacity.

Belding Tank Technologies manufactures fibreglass tanks from 2-30 feet in diameter for a number of applications, including chemical processing, food processing, iron & steel, waste water treatment and metal finishing. The company's offerings feature cone bottom, dish bottom, flat bottom, horizontal and double wall tank designs built to rigorous standards.

Tank peripherals

Canongate Technology has upgraded the specification on its non-invasive LPG level gauges. The Vesselcheck ST series is available for all sizes of LPG tanks and all tank thicknesses, while maintaining their high accuracy.

Vesselcheck ST1A is aimed at budget installations or smaller tanks. The software enables LPG suppliers to find a level-measurement solution for their whole depot from a single supplier, which can all be connected to their control system.

The sensor itself is entirely non-invasive, highly reliable as it has no moving parts and is extremely durable meaning it can withstand just about any temperature conditions thrown at it (Fig. 2). Combined with the new software and processor unit can provide an accuracy of +/-2mm on most applications.

Meanwhile, Vega non-contact radar sensors have been used to measure basic road-salt stockpile levels in storage silos and storehouses in Germany. In addition to the data transfer to Salt Manager, levels can be displayed locally on site with the weatherproof, backlit indicating and adjustment module Plicscom mounted at ground level. With its radar sensor Vegapuls 67, Vega provides measurement technology that is immune to dust clouds, condensate and salt build-up. Being non-contact there is no risk of abrasion damage to the sensor and the plastic-encapsulated antenna system and highly resistant plastic housing provide optimum protection. Latest radar versions with integrated radio or GPRS technology simplify the transmission of the data and installation of the units.

With its ED752, Baumer is offering a pressure transmitter for all kinds of hydrostatic level and depth measurement. In its standard version, the ED752 is entirely made of stainless steel, but it is also available in a Hastelloy C version. It can be delivered in an ATEX version for applications in hazardous areas up to zone 0 and it complies with the protection class IP68

Honeywell Enraf provides a comprehensive range of products and systems for accurate tank gauging, inventory management and tank terminal operations. The company is particularly focused on solutions that offer modular designs and solid migration paths. These include tank inventory solutions, terminal automation solutions, portable tank gauging and custody transfer solutions.

For example, the company's Enraf Entis XL and Entis Pro focus on the specific aspects of inventory control, custody transfer, and oil movements and operations. Terminal Manager integrates with the Experion process knowledge system platform and other Honeywell solutions to provide an integrated terminal automatic solution (Fig. 3).