MechChem Africa April 2019

⎪ Products and industry news ⎪

Wedge locking washers enhance railway safety

problem of slackening as challenging a consequenceof settlement and relaxation can be overcome. “The multi-functional design of the Nord-Lock X-series offers the highest se- curity against spontaneous bolt loosening and slackening – even at the highest levels of vibration caused by rail traffic, which oftenputsboltedjointsatrisk.Thiswedge- locking construction prevents spontane- ous bolt loosening and is enhanced by an integratedspring-effect that compensates for the loss of preload due to slackening.” TheNord-LockX-series, which is quick and easy to install and remove with stan- dard tools, has been certified for quality and safety by TÜV, a leading international institute inquality and safety certification. Eachwasher pair has cams on one side and radial teeth on the opposite side to secure thebolted jointwith tension, rather than friction. The conical shape of these washers creates an elastic reserve in the bolted joint to compensate for the loss of preload and prevents slackening. On tightening the fastener, the wash- ers flatten and the serrations engage the contact surfaces. Since the cam angle

BMG’s Nord-Lock bolt securing system is based on advanced wedge-locking technology, designed to safely secure bolted joints that are exposed to severe vibration and dynamic loads in extreme conditions – including those used in the railway industry. Nord-Lock wedge-locking washers ensure there is nobolt loosening in safety- critical areas of railway bogies, coupling devices, brake systems, rail dampers and housings. This bolt securing system im- proves personal safety, reduces the risk of lost production ormaterial damage due to bolt failure and lowers maintenance requirements. “The two reasons why bolted joints normally fail are spontaneous bolt loosen- ing and slackening,” says Maryna Werner, business unit manager: fasteners, BMG. “Bolted joints in heavy industries such as the railway sector are constantly sub- jected to external forces, which results in spontaneous loosening due to vibration and dynamic loads. With the develop- ment of new materials and techniques in modern engineering such as corrosion- resistant composites, for example, the Manufacturer and minerals producer, Pratley, recently launched a new flange sealant and gasket maker in the form of a tough and elastic silicone rubber for superior sealing. The sealant can tolerate extreme temperatures of -50 °C to +300 °C for short periods, and is chemical-resistant to petrol, diesel, paraffin, water, oil, and anti-freeze. “Our new RTV Silicone Gasket Maker hasnonegativeeffect onelectrical compo- nents such as vehicle sensors,” says Mark Bell, manager: national sales and market- ing, Pratley. In addition, it is non-corrosive, and is the ideal product for applications in engine sumps, gearboxes, pipeflanges and water pumps, to name a few.” TheGasketMaker falls under Pratley’s increasing range of adhesives for the automotive industry, including Pratley

BMG’s Nord-Lock bolt securing system is based on advanced wedge-locking technology designed to safely secure bolted joints exposed to severe vibration and dynamic loads in extreme conditions.

‘ α ’ is greater than the thread pitch ‘ β ’, the wedge-locking effect will prevent any rotation of the fastener. Directly after tightening, the joint settles and the fastener sinks into the surface material. The washers immediately deflect and the spring-effect counteracts the slackening movement of the bolt, thereby preventing loss of preload in the joint. www.bmgworld.net

Pratley launches new gasket maker and flange sealant Wondafix Car, Pratley Pratlok ana e r ob i c t h r e ad l o c k - ers, Pratley 1-2-3, Pratley Ezeebond, Pratley Powda Bond, Pratley Safety Cleaner, and more. This year will also see

Pratley embark on Phase 2 of its R&D drive, which will focus mainly on new prod- uct launches. In addition, the manufacturer plans a hi-tech automation upgrade of its factory. This follows on from

Pratley’s new flange sealant and gasket maker is chemical-resistant and can tolerate a wide temperature range for short periods.

business. Our new RTV Silicone (Grey) Gasket Maker is an example of a refine- ment of our product range to cater for specific end-user requirements, as well as to allow us to tap into a diverse range of niche markets,” concludes Kim Pratley, CEO, Pratley. www.pratley.com

its recent commissioning of a high-end electrical testing laboratory focusing on the IEC 60079 specification for hazard- ous environments, in particular. It has also invested in state-of-the-art equipment for its adhesives R&D laboratory. “Innovation remains at the core of our

April 2019 • MechChem Africa ¦ 35