Among the basic components of every hydraulic system is a series of hoses and couplings that transport fluid under pressure between the fluid ports.
Technicians and system fabricators dealing with hydraulic hoses in their industrial assemblies are aware of the complexity of selecting the right hydraulic hoses and matching them with the right couplings and fittings.
Hose selection involves several aspects, including picking the correct hose size, with adequate rated working pressure and a covering that can resist abrasion.
Choosing the right connection is also challenging. Suppliers offer hydraulic hoses, couplings and fittings in accordance with different international standards, making it difficult to determine the compatible fittings for each hose.
To avoid complexity, when selecting a hydraulic hose and coupling system or fabricating an aftermarket assembly, the first step must be to match hoses and couplings from the same manufacturer.
The Society of Automotive Engineers (SAE), which establishes the American standards for most hydraulic hoses, recommends against using couplings from one manufacturer and hoses from a different manufacturer interchangeably.
That’s because different manufacturers use different materials that can result in a variety of hose styles. They design their hose and coupling components to fit their own tolerances. Hoses from various manufacturers may have similar dimensions and constructions, but different rubber compounds and reinforcement materials. Couplings are individually designed and tested to handle the hose manufacturer’s unique product. Also, the proliferation of thread ends from around the world in recent years has dramatically increased the possibility of mismatching threads and seats on various couplings.
To complete the hydraulic assembly system process, it is important that hose fabricators follow the assembly recommendations, and use the crimping equipment of the hose and coupling manufacturer. An improperly matched or coupled hose will likely fail, causing downtime and possible personal injury.
A simple solution
Realising the importance of properly matched systems and with a view to reduce the complexity of fabricating fluid systems, Gates Australia offers an integrated solution.
The MegaSys range of hoses, couplings and crimps offered by Gates Australia use a simple matching system that makes it easy to identify the right hoses based on the pressure demand, as well to match the hoses with suitable couplings and crimps.
MegaSys hoses have colour-coded laylines and constant pressure ratings through all sizes, making the hoses easier to identify in stock and in service while reducing inventory requirements. The layline indicates hose trade name, size and pressure; SAE, EN or DIN standard; and US MSHA flame resistance compliance.
The color-coding also makes it easy to determine the maximum working pressure each hose is designed to tolerate. The colours marked on the side of the hoses are each linked to a maximum working pressure, ranging from 3,000 psi to a maximum of 8,000 psi.
The hoses are further classified into four grades according to their resistance to impulse – following the requirements specified in ISO 18752 for wire- or textile- reinforced hydraulic hoses.
The MegaSys line consists of constant pressure spiral-wire and wire-braid hoses that can be bent up to one-third SAE specifications. Combined with innovative couplings specifically designed to crimp on these hoses, leak-free performance is guaranteed up to maximum working pressures as high as 8,000 psi.
The icons and specifications printed on the side of the hoses specify the type of Gates’ coupling and crimps suitable for each hose.
MegaSys spiral-wire constant pressure hoses are available with the Gates abrasion-resistant MegaTuff and XtraTuff covers. MegaSys is tested to one million impulse cycles with a temperature range of -40 to +121°C.
MegaSys hoses are compatible with the strongest Gates fittings, including the MegaCrimp one-piece high-pressure fitting, designed for one- and two-wire braid hoses, and the GlobalSpiral two-piece ultra- high-pressure fitting, designed for four- and six-spiral wire hoses up to 8000psi.
All Gates couplings are protected, at the minimum, with TuffCoat plating, which offers and extra measure of protection against corrosion. In salt spray tests carried out by Gates, TuffCoat plating resisted red rust formation for >840 hours – over 1000 per cent greater than the SAE’s 72-hour standard.
Preventive maintenance to reduce downtime
Once a hydraulic system has been installed and is operational, it is important to closely monitor how the equipment sounds and functions. Regular inspection helps ensure that equipment is running strong, raises red flags, and in the long run, saves the heavy costs incurred through downtime or equipment failure.
Costly repairs can be eliminated through regular maintenance and choosing hoses with high abrasion resistance.
In one example studied by Gates, converting all of the assemblies to Gates MegaSys with MegaTuff cover led to 37 per cent reduction in downtime and 25 per cent fewer hose failures.