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As its tools and technologies advance, modern fluid power systems are under greater pressure than ever before to perform safely and precisely. Stronger performance leads to greater productivity and profits across a wide range of industries – from oilfield and mining to mobile equipment and marine. This eBook explores challenges in the field and highlights innovative approaches to testing, safety measures, and diagnostics and monitoring.

In this chapter, we present solutions to these common hydraulic hose assembly issues: mismatched components, poor performance, the environmental impact of failed systems, and corrosion.

INNOVATIVE SOLUTIONS FOR HYDRAULIC SYSTEM CHALLENGES

MODERN TECHNOLOGIES FOR SAFETY AND PRECISION

TODAY’S ADVANCED HOSE AND HYDRAULIC SYSTEMS

CHAPTER 1

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Quick Tip >>>

The Society of Automotive Engineers (SAE) recommends against using couplings from one manufacturer with hoses from another manufacturer interchangeably. SAE documents are available through its customer service line – 724-776-4970.

MISMATCHED COMPONENTSEvery hydraulic system includes a series of hoses and couplings that transport fluid under pressure from a pump to an actuating mechanism, which in turn converts the fluid into motion or force. That makes the hose and couplings a critical sub-system of the larger hydraulic circuit.

Suppliers offer countless types and styles of hydraulic hoses, couplings, and fittings. Because of industry-wide pressures to contain costs and solve challenges quickly, engineers often match hose from one manufacturer with couplings from another. Mixing components, as opposed to taking a systems approach, can have consequences ranging from minor leaks to major safety hazards. With the high pressures and temperatures of today’s compact hydraulic systems, employing systems with mismatched components leads to unanticipated downtime and maintenance costs.

TAKING A SYSTEMS APPROACH

When selecting an OE hydraulic hose and coupling system or fabricating an aftermarket assembly, one’s first step should be matching hoses and couplings from the same manufacturer.

Although most American-made hydraulic hoses and many imported hoses are built to conform to SAE specifications, SAE allows a wide range of materials to be used. Different materials result in a variety of hose styles, and each manufacturer designs its hose and coupling components to fit distinct tolerances.

Hoses from various manufacturers may have similar dimensions and constructions but different rubber compounds and reinforcement materials, for example.

In addition, couplings are individually designed and tested to handle the hose manufacturer’s unique product. 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.

The following sections include recommended approaches to selecting hose and couplings.

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STAMPEDS = SizeT = TemperatureA = ApplicationM = Material to be conveyedP = PressureE = Ends or couplingsD = Delivery (volume)

Quick Tip >>>

Before cutting an original hose assembly, measure the overall assembly length and coupling orientation. This measurement will be required to build the replacement assembly or match the hose I.D. to the port size.

TEMPERATUREWhen selecting a replacement assembly, two areas of temperature must be considered. These are fluid temperature and ambient temperature. The hose selected must be capable of withstanding the minimum and maximum temperatures of the system.

APPLICATIONDetermine where or how the replacement hose or assembly is to be used. Consider every factor, including the type of equipment, working and surge pressures, fluid and ambient temperatures, fluid compatibility, environmental conditions, routing requirements, minimum bend radius, expected service life, and beyond. Most often, only a duplicate of the original hose will have to be made, provided the original hose assembly gave acceptable service life.

SIZEThe inside diameter of the hose must be adequate to keep pressure loss to a minimum and avoid damage to the hose due to heat generation by excessive turbulence. Velocity of hydraulic fluid in suction lines should always fall within a specific range recommended to ensure efficient pump operation. To determine the replacement hose size, read the layline printing on the side of the original hose. If the original hose layline is painted over or worn off, the original hose must be cut and the inside diameter measured for size.

HOSE SELECTIONTo take into account the hose performance characteristics and the demands of a particular application,a simple and easy method is used to properly select hydraulic hose: STAMPED.

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MATERIAL TO BE CONVEYEDSome applications require specialized oils or chemicals to be conveyed through the system. Hose selection must ensure compatibility of the hose tube, cover, couplings, and O-rings with the fluid used. Additional caution must be exercised in hose selection for gaseous applications where permeation can occur.

Permeation is seepage through the hose resulting in loss of fluid. This may occur when hose is used with fluids such as liquid and gas fuels, refrigerants, helium, fuel oil, or natural gas. Consider whether there are potential hazardous effects of permeation through the hose, such as explosions, fires, and toxicity. Refer to applicable standards for specific applications such as fuels and refrigerants. If gas permeates through the tube, consider pin-perforated covers to prevent gas build-up under the cover. Also consider the compatibility of the system fluid not only with the tube but also with the braid, cover, fittings, and other components since permeation may expose the entire hose assembly to the system fluid.

PRESSUREIn the hose selection process it is essential to know the system pressure, including pressure spikes. Published working pressures of the hose must be equal to or greater than the system pressure. Pressure spikes greater than the published working pressure shorten hose life.

ENDS OR COUPLINGSIdentifying the proper end connectors, the hose barb end, and the port-connecting end for a hose assembly is critical. Find additional information in the “Coupling Selection” section of this chapter.

DELIVERYThe amount of fluid that must pass through a hose determines the size of hose needed. Under-sizing a hose leads to increased pressure loss, while over-sizing the hose adds unnecessary cost, weight, and bulk.

COUPLING SELECTIONThe amount and types of machinery being imported into the United States is growing dramatically as the marketplace becomes more global. The primary difference between a conventional SAE coupling and a foreign coupling is the thread configuration and seat angle.

It is important to be aware of these differences and be able to correctly identify all the different types of couplings.

International thread ends can be metric, measured in millimeters, but also include British Standard Pipe (BSP) threads, which are measured in inches. Knowing the country of origin for a piece of equipment provides a clue as to what type of thread end is used.

Quick Tip >>>

Burst pressures are reference pressures intended for destructive testing purposes and design safety factors only. Typically, for dynamic hydraulic applications, the minimum burst pressure rating is four times that of the maximum working pressure rating.

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Just as components from different manufacturers cause hydraulic system issues and lead to failure, hose assembly performance suffers when parts are not properly installed. All systems must be compliant with SAE or ISO (International Organization for Standardization) requirements, so most engineers choose hoses based on the published specifications. Often they assume that assemblies will be built correctly and perform as intended. Of course, that does not account for human error, and over-crimping or under-crimping certainly affects performance.

Quick Tip >>>

Always check the crimp diameter to ensure that it is within the published limits. Record your actual crimper setting to achieve the specified crimp diameter for future use.

ASSEMBLY PERFORMANCE ISSUES

Basic Crimp Procedures

Always reference the operator’s manual for instructions specific to individual crimpers. Also remember to wear safety glasses and to keep hands and clothing away from moving parts.

1. Refer to a crimp data chart for skive data, die selection, finished crimp diameter, and approximate crimp setting.2. Load the selected dies into the crimper. When using a die set for the first time, apply a thin coat of lubricant to the contact surface and cone but not to the bore of the die. This layer of lubricant must be thinly re-applied when contact surfaces become shiny. Locate dies in the crimp position.3. Adjust the machine to the proper crimp setting.4. Adjust the depth stop if necessary.5. Insert the assembly, and locate it with the die fingers.6. Install a die cone if needed.7. Activate the crimp mechanism.8. Remove the assembly from the dies, and measure the crimp diameter.

Deutsche Industrial Norme (DIN) fittings indicate a German or Swedish manufacturer, while BSP is found on British equipment. Japanese Komatsu machinery uses Komatsu fittings with metric threads, while other Japanese equipment most likely uses Japanese Industrial Standard (JIS) BSP threads, or in some cases, BSP straight or tapered threads.

Three determinations are required for correct identification of these couplings:› Seat: Inverted (BSPP & DIN), regular (JIS & Komatsu), or flat (flange, flat-face)› Seat Angle: 30° (JIS, BSP, DIN and Komatsu) or 12° (DIN)› Threads: Metric (DIN or Komatsu), BSP (BSPP, BSPT or JIS), or tapered (BSPT or JIS tapered)

The coupling or hose interface must be compatible with the hose that is selected. Follow the hose manufacturer’s coupling recommendations only. The proper mating thread end must be selected so that leak-free sealing can be made to mating components.

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Quick Tip >>>

When replacing hose that has no visual indicators or specs, refer to the system manual for guidance as to the correct hose type. And always remember the three Fs: Fit, Form, and Function.

MegaSys® Products

MegaSys® hoses from Gates Corporation feature an exclusive layline treatment that helps users identify crimping specifications, match hoses with the right couplings, and identify hoses in stock and in service. The distinctive design and pressure-related, color-coding system is just one benefit of the constant pressure spiral-wire and wire-braid hoses.

Other benefits of MegaSys include:

• Bends up to one-third SAE bend radius specifications• Saves overall hose assembly length• Facilitates easier plumbing and routing in tight applications• Eases installation with higher flexibility• Lowers inventory requirements• Reduces costs by as much as 64 percent

To learn more about the hoses and their innovative coupling counterparts – MegaCrimp® and GlobalSpiral™ – visit our website.

CONFIRMING PROPER COMPONENTS

During the assembly process, crimp specifications are often unknown, but other basics (like hose length) are clear. One solution for ensuring that proper components are selected, and that a system will perform as expected, has been instituted by leading manufacturers, including Gates Corporation. The manufacturers help OEs document and verify parts supplied by third parties. How? Every fifth component in a parts kit is certified by an independent laboratory or by internal quality control personnel.

If the extra component does not meet system requirements, it is likely that other items in the kit will not. If time and again the part is correct – the right length, the right cleanliness, etc. – it is likely that the assemblies are being built properly. This is an especially useful process when applications are custom and there is greater room for error.

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Quick Tip >>>

The biodegradable oils are available as ISO 32, ISO 46, and ISO 68 specification oils. Also reference American Society for Testing and Materials (ASTM) standards ASTM-D-6006 (Guide for Assessing Biodegradability of Hydraulic Fluids) and ASTM-D-6046 (Standard Classification of Hydraulic Fluids for Environmental Impact).

The costs and legal repercussions of environmental damage can be significant. Complete all certifications and testing offered by equipment manufacturers and organizations in your industry, such as the Mining Safety and Health Administration (MSHA) or the Society of Automotive Engineers (SAE), to help prevent failures that could have disastrous effects on the environment.

ENVIRONMENT-FRIENDLY HOSESToday’s most environment-friendly hydraulic hoses were designed to transfer fluid that degrades more easily than most. While restrictions around such fluid are still tight and leaks of such fluid can still be costly, the hoses are one way in which the fluid power industry is working toward cleaner, greener solutions.

The biodegradable fluid is an especially useful solution for environmentally sensitive applications where there is significant risk associated with an oil spill from a ruptured line, such as farm tractors and marine dredging.

Source: Totten, George E. (2000). Handbook of Hydraulic Fluid Technology.New York: Marcel Dekker, Inc. Pg. 514.

ENVIRONMENTAL IMPACTOne challenge for those working with hydraulics is system failure. An even greater problem can be the environmental impact that results. Where the failure occurs, the size of the spill, the type of fluid leaked, and the involvement of the industry’s governing bodies are some of the key factors that play into the costly cleanup needed to remedy the situation.

Hydraulic system failure is common – especially when systems have not been built with the right components, properly assembled, or correctly installed. In fact, it is not rare that any given fleet experiences two or more spills per year. In addition, everyday drippage is a common problem with environmental implications.

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EnviroFluid™ Hose

Biodegradable fluids can seep through ordinary hose tubes, causing cover blisters and sweat and resulting in premature and expensive hose failures. EnviroFluid™ spiral-wire hose from Gates is specially designed for biodegradable hydraulic fluids and other aggressive oils like synthetic esters, polyglycols, and vegetable oils.

Its nitrile tube handles biodegradable fluids at operating temperatures up to 250ºF without performance loss, and it offers significantly lower permeation than neoprene tubes when used with petroleum-based oils.

Learn more about EnviroFluid Hose at Gates.com.

Quick Tip >>>

If you see red rust on your coupling, it is time to replace it. When it rusts, metal loses strength and becomes unreliable.

Corrosion is a common challenge in hydraulic applications, which makes coupling selection particularly critical. Part of the process in choosing the right coupling for any given application is ensuring that is has the proper plating. Often, environmental factors must be considered, as equipment operating near the ocean, for example, contends with salt corrosion. For equipment operating inland, on the other hand, traditional plating often works. Standard plating options will not suffice when agricultural chemicals or fertilizers are moving through the system. Because there are such varied uses of hydraulic systems, manufacturers have created plating technologies for virtually every situation.

To determine the right coupling for your application, reference the chemical resistance tables that manufacturers include in their catalogs.

Rating Scale

“1” Excellent resistance“2” Good resistance“X” Not recommended“—” Testing recommended

CORROSION

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While the hydraulic system challenges outlined in this chapter are not new, leading manufacturing companies are constantly innovating solutions to respond. Sometimes the solutions are in the form of new products, developed and tested to offer greater features or unprecedented capabilities. Other solutions are less tangible and come in the form of new practices in the field, application engineering support, or training that minimizes the effects of ordinary human error. Gates Corporation is at the forefront of such advancements, and future chapters of this eBook will explore changes in testing, safety measures, and diagnostics and monitoring.

Additional ResourcesFind information on Gates Fluid Power hydraulic hose, couplings, crimpers, and accessories at www.gates.com. Gates also offers a special hydraulic preventive maintenance training program called “Safe Hydraulics” designed to help maintenance managers, repair technicians, and machine operators identify component weaknesses before failure. For information, contact pa0000@gates.com.

CONCLUSION

TuffCoat™ Plating

Introduced in 2001, TuffCoat™ plating sets the standard for corrosion resistance. Tested under SAE J516 and ASTMB117 salt-spray conditions, the plating provided more than 400 hours of protection against the formation of red rust for 500+ percent improvement over the 72-hour SAE standard.

Due to environmental concerns, Gates has eliminated hexavalent chrome from the TuffCoat manufacturing process. This green approach to manufacturing has not affected coupling corrosion resistance or changed torque recommendations.

Learn more about TuffCoat Plating at Gates.com.

As the need to replace couplings arises, purchasing them from a reputable source is the best defense against poor performance or failure.

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As its tools and technologies advance, modern fluid power systems are under greater pressure than ever before to perform safely and precisely. Stronger performance leads to greater productivity and profits across a wide range of industries – from oilfield and mining to mobile equipment and marine. This eBook explores challenges in the field and highlights innovative approaches to testing, safety measures, and diagnostics and monitoring.

In this chapter, we examine product testing as an important component of driving innovation in the fluid power field.

SUCCESSFUL PRODUCT TESTING THROUGH NEW TECHNOLOGIES & COLLABORATION

MODERN TECHNOLOGIES FOR SAFETY AND PRECISION

TODAY’S ADVANCED HOSE AND HYDRAULIC SYSTEMS

CHAPTER 2

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NEW PRODUCTS AND EXISTING EQUIPMENTToday’s testing equipment and facilities for industrial hose assemblies and product prototypes are incredibly sophisticated. Engineers, chemists, and technicians freeze, heat, abrade, impulse cycle, age, and otherwise simulate real-world conditions for thorough testing of both existing assemblies and new concepts. They evaluate compounds, metals, and designs to learn what works and what needs improvement and create microenvironments to expose materials to everything from dry air to ozone.

Testing is most successful when product application (PA) engineers from fluid power system manufacturers collaborate closely with OEMs to solve their specific challenges. Changes are immediately put into effect, rather than requiring a back-and-forth process where systems have to be re-engineered and problems repeatedly corrected.

Gates Corporation has made major headway in creating processes for efficient product and equipment testing. On site or at the company’s Customer Solutions Center (CSC), Gates PA engineers effectively work side-by-side with OEMs, their development teams, and their engineers on novel and existing platforms. Components are positioned within platforms to improve hose routing and reduce hose, coupling, and adapter cost, and custom solutions are delivered to customers.

Gates Resource Center

Gates Customer Solutions Center

The CSC is a state-of-the-art facility leading the fluid power industry in customer-focused product research, development, testing, and training.

Staffed by approximately 45 of the top engineers, scientists, and technicians in fluid power technology, the CSC is headquarters for understanding challenges and meeting fluid power needs on a global basis. The center features these testing areas:

› Materials Test Lab: A fully environmentally controlled space, ideal for developing and testing new materials, compounds, and reinforcements and ensuring compliance with stringent industry standards. › Finished Hose Test Lab: Where engineers put completed assemblies through a series of strenuous physical tests and environmental extremes. › Prototype Equipment Bay: Provides customers with a secured workplace for sensitive R&D projects. › Sample Build & Metrology Lab: Where engineers make assemblies for testing across a broad range of. › Gates crimpers and have access to sophisticated measurement equipment for analysis and microscopic examination. › Impulse Test Lab: An advanced lab that puts hoses and connectors through their paces.

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Agencies That Set Manufacturing Standards

Many governing bodies set manufacturing standards for a variety of applications around the world. They include:

ABS – American Bureau of ShippingAS – Australian StandardDIN – Deutsch/German Industrial NormDNV – Det Norske Veritas for North Sea Floating VesselsEN – European Norm/StandardGL – Germanischer LloydIJS – Industrial Jack SpecificationsRCCC – Regular Common Carrier Conference for Fleet Truck and BusSAE – Society of Automotive Engineers

United States Government AgenciesDOT/FMVSS – Department of Transportation/Federal Motor Vehicle Safety StandardsMSHA – Mine Safety and Health AdministrationUSCG – U.S. Coast Guard

NEW PRODUCT TESTINGIn developing new products, important properties of the product materials are tested in a controlled environment and detailed plans are put in place to ensure that final products will meet or exceed industry requirements.

Even with the most careful testing processes, outcomes are not always easy to predict. When Gates began designing its LifeGuard™ line-of-sight sleeving system, the first true protection in line-of-sight hydraulic applications, unexpected obstacles arose. When the aluminum collars are crimped on the assembly, it has to be done in a way that allows fluid to escape the sleeving. During testing, the desired effect could not be consistently produced using standard field tooling, so a new tool that would retrofit existing machines was designed.

In addition, since LifeGuard sleeving was designed to protect operators in cases of failure, field testing outside of fit was not an option. During product testing Gates had to be able to subject the sleeving to specific types of failure in a burst chamber. This allowed Gates to safely create pinhole leaks of specific sizes and generate bursts. Capturing video of the failures allowed the testing team to review and analyze how the sleeve and clamps reacted in each instance.

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Quick Tip >>>

Many hose products go through multiple testing iterations before meeting requirements. Even once requirements are met, couplings can blow off or leak during impulse testing, especially when high temperatures are involved. In some cases, full testing requires months of effort.

THE PROTOTYPE TESTING PROCESSOver the years, the testing process for new products has been refined. Everyone involved with the assembly assesses it, including application engineers, materials engineers, hose engineers, coupling engineers, and even marketing representatives.

Generally, the process follows these steps:1. Test procedure written 2. Procedure submitted to lab3. Lab technicians prepare samples4. Initial tests conducted5. Engineering Change Notification (ECN) submitted

The Engineering Change Notice (ECN), also referred to as an Engineering Change Order (ECO), is documentation of design changes made throughout the prototyping and life-cycle phases of a product. This documentation contains the justification for changes made to a component or system once the initial design is complete. It also forces changes to be approved by the relevant authorities.

What to Include in an ECN

According to David G. Ullman in his 2009 book The Mechanical Design Process, an ECN must contain the following information:

› Identification of what needs to be changed. This should include the part number and name of the component and reference to drawings showing the component in detail or assembly. › Reason(s) for the change.› Description of the change. This includes a drawing of the component before and after the change. The drawings must clearly show the detail(s) affected by the change.› List of documents (and in industry, the departments) affected by the change. The most important part of making a change is ensuring all pertinent groups are notified and all documents updated.› Approval of the change. As with the detail and assembly drawings, the changes must be approved by management.› Instruction about when to introduce the change — immediately (scrapping current inventory), during the next production run or at some other milestone.

6. Changes made7. Further tests conducted8. Requirements met9. Team sign off

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VEVA

Gates Value Engineering/Value Analysis is a method used to achieve necessary product and/or service functionality at minimum cost with an increase in overall value. Rather than just replacing hose and couplings with cheaper versions, engineers find ways to increase throughput and reduce labor costs. Warranty claims provide valuable insight into possible areas of improvement, and systems are retooled to eliminate leak points. At times, components can be entirely eliminated – an option that is often better than downgrading them.

For Gates, working directly with customers has made the greatest difference in creating prototypes that not only meet but exceed requirements. The company’s customized process, from design and development to testing, efficiently generates innovative solutions.

IMPROVING EXISTING EQUIPMENTWhen improving existing equipment, a preliminary meeting and onsite evaluation must take place in order to determine the project’s parameters. For Gates, once this step is complete, the machine is shipped to the CSC for prototyping and VEVA – Value Engineering/Value Analysis.

CONCLUSIONAdvanced testing processes and technologies are required to create innovative fluid power products and improve the value of existing equipment. Gates is leading the industry by combining the most sophisticated tools available with hands-on expertise from knowledgeable engineers and technicians. Only through close collaboration with OEMs are the most productive, cost-saving solutions created.

Additional ResourcesFind information on Gates hydraulic hose, couplings, crimpers, and accessories and resources related to E2E industrial hose products at www.gates.com. Questions? Contact pa0000@gates.com.

At the CSC new technologies are applied to units under analysis, and hose and coupling engineers are readily available to assess and find solutions for problem areas. Once a platform has been plumbed, Gates proposes changes to the customer who chooses which recommendations to pursue. Ultimately, the machine is sent back to the facility or proving grounds for testing.

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As its tools and technologies advance, modern fluid power systems are under greater pressure than ever before to perform safely and precisely. Stronger performance leads to greater productivity and profits across a wide range of industries – from oilfield and mining to mobile equipment and marine. This eBook explores challenges in the field and highlights innovative approaches to testing, safety measures, and diagnostics and monitoring.

In this chapter, we explore best practices for hydraulic and industrial hose system safety.

MAINTAINING A SAFE WORKING ENVIRONMENT

MODERN TECHNOLOGIES FOR SAFETY AND PRECISION

TODAY’S ADVANCED HOSE AND HYDRAULIC SYSTEMS

CHAPTER 3

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SAFETY & FLUID POWER PREVENTIVE MAINTENANCESmall hose problems can turn into catastrophes when industrial and hydraulic hose systems are not properly maintained. And as demands on fluid power applications increase, risk rises.

Implementing a preventive maintenance program helps identify component weaknesses before system failure. Start by selecting the proper hoses and fittings. Take time to ensure that they’re properly assembled, routed, and installed. Then schedule periodic inspections and troubleshoot any issues that arise. Make sure that those working on and around the equipment are properly trained to handle any safety issues they may face.

Armed with the knowledge that comes from performing preventive maintenance, companies can take action to replace or repair hose systems, reducing the instances of workplace injuries while protecting the environment and their equipment.

SAFETY FACTORS FOR HYDRAULIC HOSE SYSTEMSMaintaining a safe working environment is a necessity when working with hydraulic systems. Employees who operate or work near these systems should know the risks and potential for danger and thoroughly understand how the equipment works. There are several key factors to be aware of, including pressure, temperature, flammability, mechanical, and electricity.

Pressure: Operating pressures of hydraulic systems can be up to 10,000 psi. With this much hose pressure, even the tiniest of pinhole leaks can cause a serious medical crisis. And if the assembly is not properly installed, the couplings could come off and hit an operator or cause the hose to spray dangerous fluids. In other instances, the fitting could come apart and the loose hose could whip around, endangering those in the vicinity.

Temperature: Most hydraulic systems typically operate at 150° to 180°F, while others may go as high as 300°F. Hoses, liquids, fittings, adapters, and other metal parts can be extremely hot and, if touched, can burn skin.

Preventive Maintenance Benefits

› Increased equipment productivity › Better utilized in-shop maintenance (less emergency work) › Improved control of spare part inventory and reduce parts usage › Decreased equipment downtime › Reduced safety hazards › Increased equipment service life› Less environmental fines and clean-up costs due to leaks

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Understanding the safety factors for hydraulic hose systems and taking proper precautions to create a secure working environment will help reduce accidents, injuries, and production loss.

Quick Tip >>>

Take responsibility for personal safety. Always wear safety glasses, keep appendages away from moving parts, do not wear loose-fitting clothing, and make sure equipment is securely mounted and connected.

Hydraulic Hose Safety Tips

When working with hydraulic hose systems make sure to take caution in dangerous circumstances.

Do not touch or go near a pressurized hydraulic hose assembly. If fluid punctures the skin, even if no pain is felt, a serious emergency exists. Obtain medical assistance immediately.

If whipping hose is a potential hazard, make sure to restrain or guard the hose using clamps or protective shielding.

Precautions should be taken to eliminate all ignition sources from contact with escaping fluids, sprays, or mists resulting from hydraulic failures.

When using mobile equipment, always chock the tires to prevent rolling. Make sure to turn hydraulic equipment off before working on it. If you are performing maintenance on plant equipment, lock the control box and tag it with a warning sign stating “DOWN FOR MAINTENANCE. DO NOT TURN ON POWER.” Or, if the equipment is mobile, take the key and/or disconnect the battery so it cannot be started.

Flammability: Most hydraulic fluids that are not comprised primarily of water are flammable when they come into contact with sources of ignition, such as sparks, open flames, extremely high temperatures, and hot manifolds. Leaking pressurized hydraulic fluids can develop a fine spray or mist that can explode when ignited, causing serious injury, even death.

Mechanical: Hydraulic equipment parts move or rotate at high speed with significant force. When a hose fails, objects supported by fluid pressure can fall, causing serious damage.

Electricity: Electricity can create the spark that causes a fire, explosion, or even electrocution. During normal equipment operation, workers may be exposed to electrical hazards such as high-voltage powerlines and underground power sources. Most hydraulic hose is wire-reinforced, making it conductive to electricity. Even non-wire reinforced hose may be conductive through the rubber compound itself or moisture that penetrates a pin-pricked hose cover.

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HYDRAULIC SAFETY SOLUTIONS: A SYSTEMS APPROACHSelecting the right hoses and couplings for hydraulic equipment is a key part of preventing safety hazards. Suppliers offer hundreds of different types and styles of hydraulic hoses, and thousands of different couplings and fittings, but not all are ideal matches. Both Gates Corporation and the Society of Automotive Engineers (SAE) recommend against using couplings and hoses from different manufacturers.

Although most American-made hydraulic hoses, and many imported hoses, are built to conform to SAE specifications, SAE allows a wide range of materials to be used. Hoses from various manufacturers may have similar dimensions and constructions, but different rubber compounds and reinforcement materials, while couplings are individually designed and tested to handle the hose manufacturer’s unique products. 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. Just one improperly matched coupling could cause a hose leak or the ends to blow off.

Taking a systems approach to hose selection ensures that the hydraulic assembly is tested together with matching components and is less likely to fail, reducing injuries.

LifeGuard® Line-of-Sight Sleeving System

Gates has engineered the first sleeving system specifically designed to protect operators, equipment, and the environment from the hazards of catastrophic hydraulic hose failure.

HOW IT WORKSThe LifeGuard® sleeve is slipped onto the hose and clamped at each end. If a hose burst or pinhole leak occurs, escaping pressures and fluids are contained by the sleeve material and then exit the system via openings at each end, creating a noticeable pool of leaking fluid, alerting operators to the need for replacement.

The LifeGuard sleeve was rigorously tested both in the lab and in the field to verify its performance and capabilities at typical fluid pressure and temperature levels. It meets a variety of industry standards, including ISO 3457, which requires operator protection within a three-foot line-of-sight of any hose conveying fluid above 725 psi at 120°F (49°C), and MSHA’s flame-resistance requirements.

SAFETY FACTORS FOR INDUSTRIAL HOSE SYSTEMSIndustrial hose applications are demanding. They operate at higher working pressures and temperatures than hydraulic applications and transfer hazardous materials, such as corrosive chemicals, LP gas, petroleum products, and steam. However, much like hydraulic hose systems, If they aren’t designed, installed, and maintained properly, they can be a huge safety risk, causing leaks, bursts, whipping hose, fire, high force movement, explosions, and electrocutions.

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Choosing the Right Hose

An improperly matched hose can be a safety nightmare. To find the proper hose for an application, use the STAMPED acronym to remember important characteristics.

Size› I.D. (inside diameter)› O.D. (outside diameter)› Length› Flow rate requirements (GPM for liquids; CFM for gases)

INDUSTRIAL SAFETY SOLUTIONS: A SYSTEMS APPROACHAs with hydraulic hose systems, if an industrial hose is improperly matched with fittings from a different manufacturer, it can pose a safety risk. Taking the time to properly match all the components, or taking a systems approach, is important for a safe working environment.

Selecting the right hose will ensure proper performance for the material being transferred. It will also minimize the risk of property damage or bodily injury due to leaks, bursts, or ends blowing off. Use STAMPED to remember hose selection characteristics.

Keep in mind that taking a systems approach involves more than a quick glance at a hose manufacturer’s chemical resistance tables; it takes careful study and analysis. Hose compounds with identical names are more complex than they might appear. For example, a tube made from the EPDM elastomer may differ from another EPDM tube because of differing ingredients such as accelerators, age resistors, vulcanization agents, carbon black, or processing aids. Due diligence in hose selection can create a safer working environment and prevent costly accidents.

Industrial Hose Applications

Typical industrial hose applications, as identified by the National Association of Hose & Assembly Distributors (NAHAD), include the following:

› Air Hose › Asphalt › Chemical—Plastic Lined › Chemical—Rubber Lined › Food Handling—Regulated › Food Handling—Non-Regulated › Lay Flat

› Material Handling—Bulk Transfer› Material Handling—Cement› Petroleum› Push On› Sandblast› Steam› Water/Multi-Purpose

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Other Industrial Hose Selection Factors

Some additional industrial hose selection considerations from NAHAD are:

› Abrasion› Electrical conductivity

Choosing the Right Hose (cont.)

Temperature› Ambient temperature› Internal temperatures› Temperature impact on material being conveyed

Application› Where the hose will be used› How the hose will be used› How often the hose will be used› Environmental conditions› Special hose construction needs› Conductivity requirements› Critical applications (flammable fluids, compressed gas, steam, etc.)› Government or industrial standard requirements

Material Being Conveyed› Chemical name(s) and state(s)› Food, pharmaceuticals, cosmetics› Dry or powder› Liquid

Pressure› Working pressure› Maximum surge pressure› Vacuum

End Requirements› Type of end connections/couplings

Delivery› How many items and when they need to be supplied› Special packaging or branding requirements

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Other Industrial Hose Selection Factors (cont.)

› Environment› Flammability› Flow rate› Fluid velocity› Movement (type, distance, frequency)› Ozone› Permeation (vapor conveying hose)› Pressure drop› Routing› Salt water› Static electricity› Ultraviolet light› Vibration (frequency rate – Hz, amplitude – “G” load)

Don’t forget to carefully consider fittings as well. Some factors to consider in selecting the proper hose couplings include:

› Hose size› Compatibility with the material being conveyed› Installation design and attachment options› Corrosion resistance› Thread type (hose end and thread end)

CONCLUSIONInjuries incurred while working with hydraulic and industrial applications are avoidable. For a safe working environment, start by taking a systems approach to selecting your components and follow up with regular preventive maintenance to ensure that the proper precautions are taken to decrease injury and loss of life.

Additional Resources

Find information on Gates hydraulic hose, couplings, crimpers, and accessories and resources related to E2E industrial hose products at www.gates.com. Questions? Contact pa0000@gates.com.

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As its tools and technologies advance, modern fluid power systems are under greater pressure than ever before to perform safely and precisely. Stronger performance leads to greater productivity and profits across a wide range of industries – from oilfield and mining to mobile equipment and marine. This eBook explores challenges in the field and highlights innovative approaches to testing, safety measures, and diagnostics and monitoring.

In this chapter, we examine the evolution of hose life monitoring and diagnostic solutions.

ADVANCEMENTS IN HOSE MONITORING, DIAGNOSTICS, AND IDENTIFICATION PRACTICES

MODERN TECHNOLOGIES FOR SAFETY AND PRECISION

TODAY’S ADVANCED HOSE AND HYDRAULIC SYSTEMS

CHAPTER 4

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When fluid power equipment fails, it is costly in terms of time, money, and production loss. All types of equipment in the field, from drilling rigs to wind turbines, rely on hose systems to operate efficiently. Monitoring the condition and performance of hose systems and properly predicting hose life can mean the difference between routine maintenance time and catastrophic downtime.

HOSE MANAGEMENT SOLUTIONS

Gates Hose Management Services

Gates Engineering & Services (E&S) offers Gates Hose Management, a risk-based management program for hose assemblies. It is based around the UK Offshore Operators Association (UKOOA) Flexible Hose Assembly Standard (FHA) and is designed to reduce risk in all aspects of operations by:

› Quantifying productivity requirements, safety risks, and environmental risks.› Understanding customer FHA program and usage.› Evaluating client practices and recommending steps for improving FHA, QA, and HSE.› Performing necessary installations and services on-site.› Developing integrity-based inspection, maintenance, and recertification strategy.› Providing hose monitoring and diagnostics powered by Gates Sentry™ Services for reliable operation and continuous improvement.

For more information about Gates Hose Management Services, call 1-972-664-9287.

TEMPERATURE, PRESSURE, AND HOSE LIFEHydraulic hose life is impacted by a number of conditions, but most instances of failure arise from issues found inside the hose: extreme temperatures and significant changes in hose pressure.

Exposure to internal or external temperatures that exceed a hose’s specifications can cause its synthetic rubber compounds to harden, reducing flexibility and making it more susceptible to cracking. Similarly, when a hose operates at low ambient temperatures (-40° and lower), it may become less flexible or brittle and crack.

Pressure also affects hose integrity. While a drop in pressure from the time the fluid enters a hydraulic hose assembly to the time it leaves is to be expected, it may be necessary to control it for optimum system performance.

For most dynamic hydraulic applications, the minimum burst pressure is four times the maximum working pressure rating. The working pressure of any hose used should be greater than or equal to the maximum system pressure. This generally increases cycle life. In fact, Gates testing has found that using a hose at 50% below its rated working pressure will approximately quadruple the cycle life.

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TEMPERATURE, PRESSURE, AND HOSE LIFEHydraulic hose life is impacted by a number of conditions, but most instances of failure arise from issues found inside the hose: extreme temperatures and significant changes in hose pressure. Exposure to internal or external temperatures that exceed a hose’s specifications can cause its synthetic rubber compounds to harden, reducing flexibility and making it more susceptible to cracking. Similarly, when a hose operates at low ambient temperatures (-40° and lower), it may become less flexible or brittle and crack.

Pressure also affects hose integrity. While a drop in pressure from the time the fluid enters a hydraulic hose assembly to the time it leaves is to be expected, it may be necessary to control it for optimum system performance.

For most dynamic hydraulic applications, the minimum burst pressure is four times the maximum working pressure rating. The working pressure of any hose used should be greater than or equal to the maximum system pressure. This generally increases cycle life. In fact, Gates testing has found that using a hose at 50% below its rated working pressure will approximately quadruple the cycle life.

While it’s necessary to ascertain the external condition of a hose with a visual inspection, to get a clear picture of the state of the hose, internal factors such as temperature and pressure need to be closely monitored as well.

TRADITIONAL HOSE MONITORING & IDENTIFICATION PRACTICESFor years, mobile equipment operators and fleet managers have relied on basic identification and monitoring processes. Hoses have stainless steel tags affixed to them that are logged for identification and operators keep records of which hoses have been replaced and when. Hoses and connectors are visually inspected at regular intervals to check for signs of cracking, abrasion, wear, leaks, corrosion, or other indicators that indicate failure is imminent.

While visual inspections have been the most common way to inspect the hose assembly, operators have the option of paying for costly fluid chemical analyses and filter inspections to try to establish internal hose conditions.

Unless there are warning signs, there is no clear indication that a hose will fail simply due to age. Typically, hoses are replaced in accordance with manufacturer’s suggested life and operational experience.

Traditional hose monitoring methods rely heavily on visual examinations and require a lot of maintenance time. Factors on the inside of the hose play a large part in the overall hose life, and relying solely on the external conditions of the hose misses that key component. An operator may replace a hose that has valuable service life left too soon based on the manufacturer’s recommendations. Or he may not realize that pressure spikes and temperature within the hose have degraded the hose quality so much that failure (and possibly injury or costly cleanup) is imminent.

Quick Tip >>>

The minimum impulse cycle life found in SAE J517 can be used as an indicator of expected hose cycle life. However, remember that different hose types, and in some cases hose sizes, have different expected cycle lives. Some hose manufacturers have products that far exceed SAE minimums.

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RFID 101

Radio Frequency Identification (RFID) is a technology that uses radio waves to transmit information from electronic tags to a reader in order to identify or track objects. An RFID system consists of a tag that includes a chip, antenna, and a reader. The RFID reader transmits radio waves to the tag at a specific frequency. Upon receiving them, the tag sends back information to the reader. The reader then translates the waves into digital information and pulls relevant data from the computer database. RFID tagging is used on several objects, from pets’ microchips to library books. Even casinos use the technology. They place RFID tags on high-value chips in order to identify counterfeit chips and instances of card counting, and to track betting habits.

TRADITIONAL HOSE MONITORING & IDENTIFICATION PRACTICESFor years, mobile equipment operators and fleet managers have relied on basic identification and monitoring processes. Hoses have stainless steel tags affixed to them that are logged for identification and operators keep records of which hoses have been replaced and when. Hoses and connectors are visually inspected at regular intervals to check for signs of cracking, abrasion, wear, leaks, corrosion, or other indicators that indicate failure is imminent.

While visual inspections have been the most common way to inspect the hose assembly, operators have the option of paying for costly fluid chemical analyses and filter inspections to try to establish internal hose conditions.

Unless there are warning signs, there is no clear indication that a hose will fail simply due to age. Typically, hoses are replaced in accordance with manufacturer’s suggested life and operational experience.

Traditional hose monitoring methods rely heavily on visual examinations and require a lot of maintenance time. Factors on the inside of the hose play a large part in the overall hose life, and relying solely on the external conditions of the hose misses that key component. An operator may replace a hose that has valuable service life left too soon based on the manufacturer’s recommendations. Or he may not realize that pressure spikes and temperature within the hose have degraded the hose quality so much that failure (and possibly injury or costly cleanup) is imminent.

NEW TECHNOLOGY FOR HOSE MONITORING, DIAGNOSTICS, AND IDENTIFICATIONToday’s technology enables companies to streamline their hose management processes. Identification, monitoring, and diagnostics are no exception. While stainless steel tags and manual logs have long been standard, new radio frequency identification (RFID) and tagging have revolutionized monitoring practices.

Instead of identifying hoses using stainless steel tags, high-tech RFID tags can be affixed to all hose assemblies in the field. Each tag, when scanned by a hand-held RFID reader, provides data including hose type, size, length, end fittings, location, orientation, test certifications, assembly notes, bill of materials (BOM), and other important data. The information can be read or updated on-site and synchronized with a PC database. If a hose needs to be serviced or replaced, personnel can easily scan the tag to obtain its information and determine the correct assembly. Taking the process from manual to digital, RFID tagging is efficient, saving time and money.

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Gates Sentry™ Services

Gates Sentry™ Services, a comprehensive preventive maintenance solution, allows fleet managers and equipment operators to estimate remaining hose life and accurately identify hoses that need to be replaced.

Sentry Services consists of Sentry™ IQ and Sentry ™ ID:

Sentry ID offers real-time monitoring and diagnostic information about the current operating condition and performance of hose assembles. It provides warnings based on a pre-established set of reporting parameters:

› Service warning for any of the monitored hoses› Warning of over-temperature or over-pressure conditions› Warning of any system faults such as failed sensors, cabling or ECU

Sentry IQ is an RFID tagging system that identifies and tracks specific hose assemblies worldwide.

High-frequency Sentry ID tags provide easy field access to any hose data deemed important. This includes, but is not limited to, hose type, length, location, size, bill of materials (BOM), assembly notes, maintenance records, photographs, and installation instructions.

For more information about Gates Sentry Services, visit our website.

While visual hose inspections are still necessary, installing sensors on different parts of each hose in a system allows operators to monitor pressure pulsations and temperatures for each hose. This information is sent to an electronic control unit (ECU), which can be programmed to calculate a hose’s remaining ser-vice life and warn users of out-of-spec conditions. The data can help personnel determine when to order replacement parts and anticipate downtime, reducing the likelihood of unexpected catastrophic hose failure and helping control costs.

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CONCLUSIONVisually inspecting external hose components is an important part of preventive maintenance. However, to truly understand hose condition and predict remaining service life, it is necessary to use available technology to monitor temperature and pressure changes inside the hose. Recent advances in RFID technology help streamline the maintenance process, preventing catastrophic hose failure, reducing downtime, and saving money.

Additional Resources

Find information on Gates hydraulic hose, couplings, crimpers, and accessories and resources related to E2E industrial hose products at www.gates.com. Questions? Contact pa0000@gates.com.