Hydraulic hose, which is used in a variety of industrial hydraulic equipment, plays a very vital role in the performance and efficiency of the equipment. With safety being of paramount importance in hydraulics, users are demanding safer/sturdy hoses to effectively prevent leakages. OEMs are also demanding more compact hoses that offer a longer life, more flexibility and a higher operating pressure and temperature.

 

Hydraulic systems are widely used in off-highway (mobile) equipment when heavy force or torque is involved, such as lifting loads of several tonnes, crushing or pressing strong materials like rock and solid metals, and digging, lifting, and moving large amounts of earth. “A hydraulic hose assembly plays a very vital role in the performance and efficiency of a hydraulic equipment. The proper selection of hose, compatibility between hose and fittings and installation of the hose assemblies are important factors for consideration,” says Sriram Venkatraman, General Manager, Fluid Connectors Group, Parker Hannifin India, which has a complete range of products to offer port to port solutions for all equipment. 

 

A hydraulic hose is specifically designed to convey hydraulic fluid to or among hydraulic components, valves, actuators, and tools, and play very important role in ensuring efficiency of an equipment. “Hose fittings have an impact on the overall efficiency and safety of a hydraulic system. Non-skive hose assemblies, improved cleanliness level and complete kit solution (hose, fittings, adapters and tube fittings) prevents premature hose failure which in turn improves the efficiency. Compact hose and improved fitting design reduces weight of the system which helps improve the performance of the machine. Hydraulic hoses bring about the flexibility needed for the operations of the various actuators in these equipment. Hoses also help in absorbing the high vibrations these machines are subjected to where rigid pipes or tubes will invariably fail. A hydraulic hose meets all these application requirements, while serving the basic purpose of conveying pressurised fluid between various components within a hydraulic system,” states Shandar Alam, Managing Director - Hydraulics and Vehicle, India, Eaton, which offers hoses in all ranges and sizes from 250 to 16,000 psi and extensive range of industrial hoses right from air/water transfer to high abrasive and high critical applications like cement, concrete transfer, dry material and bulk transfer, mud suction and discharge etc.

 

Hoses and couplings play critical roles in how hydraulic systems perform. They transfer hydraulic fluid from the pump to machine components such as valves, motors, and actuators which use the fluid pressure and flow to create the machine motion and force needed to do work. The importance of selecting or replacing hydraulic hoses and couplings often gets overlooked, until something goes wrong. “Our customers have been telling us they want lighter, more flexible and easier-to-handle products that address multiple industry standards. They are seeking to enhance the performance of their machines, simplify their engineering processes, improve operational efficiencies and streamline inventory with a simplified selection of replacement products that can be used on virtually any original equipment platform,” says an official of Gates India, which offers hydraulic and industrial application hoses and couplings to cover most industrial applications.

 

Material of construction 

While hydraulic hose is usually constructed of multiple materials, the most commonly use materials include elastomers, fluoropolymers and silicone, thermoplastics, metal, and composite or laminated structures. For improved product performance, some of the commonly used material in hoses include chlorinated polyethylene (CPE), nitrile rubber (NBR), chlorosulphonated polyethylene (CSM) and EPDM. For fittings, carbon steel (12L14,1215, 1045) and stainless steel (304, 316 grades) ensure superior performance. For example, Eaton’s new DURA-KOTE plating technology offers up to 1,000 hours of corrosion resistance on the metal parts. Eaton also provides adapters as well as protective coils/sleeves for additional hose protection on extreme abrasive conditions in construction and mining applications.  

 

New product development and product upgradation involving innovative machines, material and process is an on-going process in Parker Hannifin India. “These activities are adequately supported by robust product evaluation processes, testing laboratories and highly qualified workforce. In terms of new development, Parker offers Tough Cover (TC) and Super Tough Cover (ST) hose which ensures a metal to hose abrasion resistance multifold. Parker’s half-bend radius hose meets the extreme demanding flexibility requirements of the modern construction equipment. We also offer fittings for extreme resistance to corrosion,” observes Venkatraman.

 

Right selecting parameters

Construction applications demand higher flexibility and tighter bend radius in hydraulic hoses for enhanced installation and routing capabilities on equipment. Hoses have to deliver higher product life and abrasion resistance to support extremely demanding duty applications and tough working conditions that mining and construction equipment operate in. Selecting suitable hoses and fittings for the required application thus becomes very critical. 

 

Shandar Alam explains, “Hydraulic hoses and fittings are designed to carry hydraulic fluids with high pressure and high temperature, and are important elements for hydraulic systems. The ‘STAMPED’ principle that focuses on seven factors, (namely Size, Temperature, Application, Material, Pressure, Ends, and Delivery) is generally used while selecting a hose. Fitting selection mainly depends on factors like versatility, reliability, pressure rating and applications. Eaton’s highly engineered hoses and fittings are designed to efficiently meet these application requirements.”

 

The customers are demanding lighter, more flexible and easier-to-handle products that address multiple industry standards. They are seeking to enhance the performance of their machines, simplify their engineering processes, improve operational efficiencies and streamline inventory with a simplified selection of replacement products that can be used on virtually any original equipment platform. 

 

Sriram Venkatraman says, “The customers look for a compatible hose meeting pressure and temperature requirements, followed by fittings as per application requirement taking into consideration end use, vibration and any other specific requirement of the circuit. Customers also look for the least possible variants in hose and fitting combinations. This is achieved by Parker through escalated and accelerated validation process of hose, fittings and assemblies. Parker has complete range of hoses and fittings to meet these requirements. It also offers constant pressure hoses and high temperature hoses. Fittings are offered in Metric, JIC, ORFS and BSP standards and customised requirements.”

With safety being of paramount importance in hydraulics, users are demanding safer/sturdy hoses to effectively prevent leakages. “Certainly, a lot of awareness related to safety and leakage is being created in the hydraulics industry. Nowadays, OEMs are looking for more robust hoses which will not only eliminate leakage problems, but also improve overall efficiency of the system,” states Alam.

 

The most effective way to achieve a safe system with leak-free terminations is to use matched systems for hose and couplings. The SAE J1273 standard highlights that hose and fittings from two manufacturers should not be intermixed without approval from both manufacturers, and further explains assembly equipment (ie crimpers) should also be specific to the hose and fittings manufacturer.  Sriram Venkatraman opines, “Nowadays, a ‘zero’ leakage is a must requirement of all OEMs. Parker works closely with its partners to identify the major potential areas to provide leak-free solutions with development of application-specific hoses.” 

 

What is the average life of a hose? 

The life of a hydraulic hose is the most difficult thing to predict. The operating life of a hydraulic hose assembly largely depends on the application and external aberrations. According to the specifications stated by the Society of Automotive Engineers (SAE), the shelf life of a bulk rubber hose is 10 years from the date of manufacture and is considered unlimited for thermoplastic hose, if stored in subdued light and controlled temperatures with no fittings attached. “But in use, so many variables come into play that it is impossible to exactly predict the service life of a hose assembly. However, understanding important operating parameters that affect a hose, combined with a bit of experience, can help guide users as to when an assembly should be replaced,” explains Shandar Alam.

 

The average life of a hose depends on its manufacturing process as well as its design ie tube and cover material, reinforcement, fitting integrity and accuracy etc. In addition, some important factors that impact the life of a hose are operating pressure and temperature, routing, pressure surges, ambient temperature, bend radius and fittings. According to Alam, it is very important to monitor hose assemblies and carrying out preventive maintenance as it is critical to ensure safe and productive operation of hydraulic systems and also enhance the life of the hose. 

 

In a challenging economic climate where keeping costs low is a top priority, no one wants to compromise on operator safety, spend on expensive emergency repairs and face production downtime, especially in mission critical applications where the cost of downtime is significantly higher. 

 

Shandar Alam elaborates, “As preventive maintenance, it is very important to identify component weaknesses before it fails. In the case of hydraulics, high pressures and temperatures make hose and fitting maintenance as well as component selection particularly important. Eaton’s Lifesense hose is a path-breaking technology in hose condition monitoring system. The technology is capable of forewarning the user of impending hose failure, while, the customer hitherto was dependent on either preventive maintenance that deprives the user of full life usage of the hose, or changing the hose as and when it fails, which poses potential safety issues, downtime costs and loss of expensive lube oil that is detrimental to the environment.”

 

Compact, yet powerful 

The technology is fast shifting towards high pressure and more compact machines with higher productivity, more efficiency, reliability and with guarantees on uptime. Alam elaborates, “OEMs are developing new generation machines and equipment with simplified designs and architecture that improve the overall efficiency. Adoption of mechatronics, ie integration of hydraulics with electronics, is the future. Electrification is being adopted in certain applications and circuits; use of diagnostics and prognostics on hoses for conditioning and monitoring, smart connectors and 3D printing for faster product development are some of the major technology trends we foresee in hose and fittings market.” 

 

Venkatraman adds, “The trend is to move towards compact hoses with high flexibility. Due to the customer expectations of high performance machines, OEMs are moving towards high temperature and tough covers to sustain challenging environments. The challenge to the designers is to achieve the required performance without significant impact on cost.”

 

Some interesting technology trends can be observed in the SAE (Society of Automotive Engineers) number system. Earlier specifications, like 100R1 and 100R2, focused on hose construction (one-wire braid versus two-wire braid) and had varying pressure ratings depending on hose size. Smaller hoses had higher pressure ratings and larger hoses had lower pressure ratings. Equipment designers needed to pick and choose different hoses from different product categories to match their system pressures. “More recent specs, such as 100R17 and 100R19, focus on constant system pressures. Every hose in the family has the same pressure rating, no matter the size. Also notice that compact hoses are becoming more popular because they let hoses bend to smaller radii and fit into smaller spaces. The International Standards Organization (ISO) also has hydraulic hose specifications that address the needs of global customers.  The ISO 18752 standard also focuses on constant pressure systems, and it includes options for standard and high system temperatures as well as a durability measure of impulse cycles,” states Gates India official. 

 

Emerging opportunities 

Hose and fittings have applications in diversified segments such as construction and agriculture equipment, steel mills, oil and gas, and material handling. When these end-markets do well, hose and fittings market are bound to perform and grow. “We are anticipating tremendous growth in these markets because of favourable government policies and new initiatives (smart cities, mega corridor, Bharatmala project etc) and feel that the business for hoses shall also rise in accordance,” opines Shandar Alam. 

 

The market is moving towards more compact hoses that offer a longer life, more flexibility and a higher operating pressure and temperature. On the fittings side, the current focus is on higher corrosion resistance, zero leakage and improved torque. Shandar Alam says, “The key would be to deliver greater value to equipment manufacturers while maximising uptime. This offers an opportunity for a technology- and innovation-driven organisations like ours to keep developing efficient and smarter solutions that are efficient, safe, reliable and sustainable. Eaton is already innovating in this direction and our hose solutions such as LifeSense and Dynamax are clear examples of this focus.”

To meet the evolving needs of the customers, companies are developing innovative products that push the boundaries of applied materials science and manufacturing processes. Sriram Venkatraman says, “With the launch of the Global Core hoses, Parker is working towards providing simple solutions to robust hydraulic hoses designed to endure the tough conditions. The Global Core will aim at reducing customer inventory and part number complexity by reducing the number of hoses and fitting series to meet customer expectations.”

 

Content Courtesy: Equipment India magazine

 

Quote

As preventive maintenance, it is very important to identify component weaknesses before it fails. In the case of hydraulics, high pressures and temperatures make hose and fitting maintenance as well as component selection particularly important.

Shandar Alam, MD - Hydraulics and Vehicle, India, Eaton

 

The trend is to move towards compact hoses with high flexibility. The challenge to the designers is to achieve the required performance without significant impact on cost. Sriram Venkatraman, GM, Fluid Connectors Group, Parker Hannifin India

 

Maintenance Tips

Given below are few preventive maintenance tips for hydraulic hose:

Courtesy: Gates India