Aussie innovation delivers for high temperature bolting
An Australian innovation is making light work of some of the largest and most difficult bolt tensioning applications encountered in high temperature areas of electricity generation, mining, petrochemical and other processes. In a recent application, Technofast Industries’ new EziTite® TR High Temperature Hydraulic Nuts demonstrated their performance when they were used to assemble boiler feed pumps at an electricity generating plant in South Korea. This application involved the use of 12 large EziTite® TR High Temperature Hydraulic Nuts fitted to M110 X 4.0 studs. The temperature resistant fasteners were used to replace the former method employing large torque wrenches weighing more than 125kg. The Technofast method resulted in an installation time of around thirty minutes using two personnel, compared with eight hours and four personnel using the previous method. Technofast’s Founder and Managing Director John Bucknell explained that time savings of this order, and better, are possible using the EziTite® fasteners instead of conventional methods involving sledgehammers, stud heaters and multi-jackbolt tensioners. “Large nuts of this diameter can require terrific torque forces to achieve the desired tensioning, or require ‘jacknuts’ which have multiple forcing screws to bring the job within the power range of hand tools.” “Given the damage which can occur to the fastener components and joint faces, some operators have opted to use these jacknut fasteners. However, large nuts such as those used on the Boiler Feed Pump can easily have 24 of these forcing screws per nut, and they have to be progressively and sequentially tightened to a specific torque at each step, or the individual screws will be overstressed and fail. This can add days of downtime to a typical maintenance operation.” “Also, when jacknut fasteners need to removed, the forcing screws have to be backed off in a strict sequence to avoid failure. If not, […]
