Site Completed Niplast Tanks Replace Originals After 25 Years

Site Completed Niplast Tanks Replace Originals After 25 Years

Case Study

Niplast bulk storage tanks were originally installed at the NGF EUROPE Limited St Helens site in 1988 and the replacement tanks will continue to store latex solutions for the company, part of the NSG Group, one of the world’s leading manufacturers of glass products.

However, the contract brought new challenges. The original tanks were installed as part of the site construction, being lifted into place before the plant roof was assembled. Hence, 25 years on, STF were required to undertake the demolition of the redundant tanks and complete the construction of the new tanks in situ, within the plant. STF also undertook the licensed disposal and 100% recycling of the original polypropylene tanks.

The two 30,000 litre Niplast tanks have been designed and manufactured to British and European Standard BS EN 12573 Welded Static Non-pressurised Thermoplastic Tanks which was adopted by the BSI in 2000. Manufactured from black UV stabilised polypropylene, each tank featured a 15 degree angled conical lid, ribbed to accommodate personnel loads, plus internal sloping bases running from c.500mm height to c.200mm at the outlet to assist with drainage and clean down. Overall the tanks were 3m diameter by 5.5m height, with a range of tank furniture including access manways, flanged connections for incoming latex, outlets, connections for ultrasonic content indicators and overflow.

The key tank components were manufactured at STF's Stockport factory, primarily the tank roofs, base sections and wall cylinders. They were then transported and offloaded on guided trolleys through NGF's production areas, across a distance of c.300m to the latex storage section. STF's fabricators connected the components on-site using extrusion welding, a technology which is transferred from factory to site environment ensuring successful completion of the project. Similarly, it was possible for STF to undertake its water testing and weld spark testing on site as easily as it can in the manufacturing plant.

Following fabrication of the tank components in STF's factory, on site construction, from delivery to final testing by qualified Niplast tank fabricators took one week, thereby causing minimal disruption to NGF EUROPE Limited’s production at the site.

STF Managing Director, Adrian Greenwood said, "The 25 year’s service provided by the original Niplast tanks demonstrates the excellent service life achieved by thermoplastic tanks constructed to BS EN 12573. The provision of the new tanks shows the flexibility of this design standard and the manufacturing and testing techniques."