Helping Regenerate the UK Iron and steel Industry
Despite the recent industry headlines, it is important to note that significant investment continues in other areas of the UK iron and steel industry.
Blast furnaces are fundamental to the creation of iron and steel. They are used to create iron which is then smelted to make steel. The blast furnaces need coke as part of the iron making process. The coke is created by heating coal to temperatures of 1200-1300C° in the absence of oxygen for a period of around 18 hours, a process called pyrolysis. The hot toxic gases and impurities from the coke ovens are extracted through a network of pipes and used for a variety of purposes including heat recovery.
Pioneering valve technology for over 150 years, AVK specialise in the application of coke oven valves and were the obvious choice for Port Talbot Steel Works.
AVK’s, Donkin manufactured Series 662 coke oven valves act as isolation valves on the pipe network, cutting off the flow of gases. The valves are critical but used infrequently, during shutdowns or emergencies for example. The toxic environment in which they operate, including the presence of ‘tar’, has led to the evolution of a design which is unique to coke oven valves.
On a typical gate valve the stem and yoke are housed within the body and bonnet of the valve. In a coke oven valve, to avoid the potential of corrosion from the toxic environment, the stem and yoke sit outside the body. To eliminate the build up of tar and other impurities on the face of the gate, steam flushing ports have been incorporated into the body of the valve.
A jacking point has been inserted below the valve seat to enable the gate to be opened should its movement be compromised after a long period of being in the closed position.
Coke ovens are large, often up to 20m in length and 10m high. The pipework is on the same scale. At Port Talbot, for example, two of the valves are DN1200mm and the others are DN900mm. As with all AVK products, quality is paramount. There is 100% quality control and traceability with every casting and component individually stamped.