New coupling systems designed for longwall applications

Parker Hannifin has introduced a new range of stapleless and threadless couplers designed to address the limitations of staple couplers or threaded couplers in longwall applications.

The company states the use of staple couplers resulting in an alarming number of hydraulic hose failures prompted it to develop a new stapleless coupler that will revolutionise high pressure fluid control in longwall mining.

‘Due largely to the limited annular engagement of staple fittings, the staples are vulnerable to fatigue, failure and ‘walk-out’ as well as corrosion, abrasive wear and even shape deformation resulting from their first insertion into a connector fitting,’ a statement read.

‘Various thread-retained locking mechanism couplers designed to address these problems also have several disadvantages, including the need for special tools to assemble and disassemble, and compromising the relative rotation of the coupler. The typical Longwall environment also produces a lot of fine coal dust, mud and water, which can easily corrode and clog threaded couplers or cause them to jam prematurely.’

The new Parker HPK stapleless coupler has been designed to address those flaws in the design of the staple-type coupler, as well as the practical problems associated with other threaded couplers and associated corrosion. 

Parker Mining market manager Gary Nauer adds the company went to great lengths to ensure the design was not only simple but also durable: ‘It has passed more than 1,000,000 impulse test cycles at 560 bar without failure and the special high grade stainless steel used in its construction will ensure easy operation and a long service life.’