News & Events - RYCO Hydraulics
System Cleanliness – Ratings & Filtration

In order to monitor and quantify the cleanliness of the fluid in an hydraulic system, standard rating systems have been developed over the years. These cleanliness ratings also allow us to measure the effectiveness of any filtration systems put in place to maintain the cleanliness of an hydraulic system. Cleanliness Rating Systems The cleanliness of a fluid can be measuring using a number of different standard classification systems, as outlined below. ISO 4406 ISO 4406 describes a method by which to count and record particle sizes. An average is taken by counting three size ranges. Particles greater than 4 microns. Particles greater than 6 microns. Particles greater than 14 microns. Because the number of particles within a system may be very high, the actual number is not used. Instead, a number is used to represent the value. This "class" number is based on the following table. The table below is the ISO 4406 codes. There has been two major editions of this standard, 1987 and 1999. 1999 is the current edition, and it should be used when possible. ISO 4406: ...

System Cleanliness – Contamination & Analysis

The performance of hydraulic systems can be impacted by the presence of contaminants in the hydraulic fluid. But how does contamination arise, and how can we monitor and quantify it so that we can effectively manage it and minimise any potential damage to an hydraulic system? An overview of contamination Definition in fluid power Any material, foreign to a system's fluid that has the potential to damage components within that system. Contaminants can be solids, liquids or gasses. What is contamination? There are 7 different classes of contamination: Abrasion - Hard particles causing wear Fatigue - A repeated stressing on a surface Erosion - Particles striking at high velocity Corrosion - Chemical degradation Adhesion - Particles sticking to a surface Cavitation - A vacuum being induced on a fluid Aeration - Gas bubbles within a fluid What causes contamination? There are 3 main causes of contamination: Manufacturing Contaminants can be built-in to a system during manufacture. Hoses, tubes and other components are dirty when fitted Ingress Contaminants may ingress into a system. They may gain entry through seals or tank ...

Using the Impulse Curve in Hydraulic Hose Assembly Testing

When conducting standard testing procedures on hose assemblies, the cycles of applied pressure create an impulse curve. The shape of this impulse curve is strictly controlled to ensure standardised, consistent test results. The rapid rise and fall of the pressure increase and decrease cycles must fall within the shaded limits. This happens at between 30 and 70 cycles per minute, with 60 cycles per minute being a typical frequency. This means that it only takes only one second for one impulse cycle. Example impulse test configurations For example, RYCO T3K4D: SAEIOOR17, 1/4" one wire braid hose with a maximum working pressure of 210 Bar (3,050 PSI) and maximum working temperature of +1000C would be tested as follows: Maximum Impulse Pressure: 210 Bar x 133% = 280 Bar (4,060 psi) Temperature: + 1000C Minimum Bend Radius: 50mm in 1800 arc Number of Impulse Cycles: 200,000   Four 'unaged', or new, hose assemblies must be tested, and all four must pass the impulse test. If any one assembly fails, the test is failed. It is a tough test. The rapid pressure increase ...

Impulse Testing of Hydraulic Hose Assemblies

The aim of any hydraulic hose coupling must be to grip the hose for the lifetime of the assembly, never leak or weep and never blow off the hose. The ultimate test for an hydraulic assembly is always "on the job", as this proves whether the hose and couplings can meet the demands of the application. Proving hydraulic hose designs But have you ever wondered how hydraulic hose coupling manufacturers prove their designs before releasing them for sale to the market? There are applications that combine working conditions of pressure, temperature, flexing, aging and mechanical loads the designers could never have thought of. Think of hydraulic hammers as they pound into rocks, tree harvesting machines as they lift and tilt huge tree trunks, ground engaging tools on backhoes suddenly hitting a rock or root hydrostatic transmissions suddenly being thrown into reverse gear while travelling forward. All these applications and many more put great stresses on hydraulic hose assemblies. It's not possible to design laboratory tests to simulate all the possible combinations of conditions that a hose coupling may encounter during ...

Understanding Filtration – Fluid Cleanliness & Filter Efficiency

In part 1 of this series on Understanding Filtration - Viscosity and Temperature we covered the significant impact that temperature has on the viscosity of an oil, which in turn affects its performance during filtration and lubrication. There are other factors that must be taken into account when it come to hydraulic filter selection. These variables will affect each other. To select the correct filter you need to establish the expected fluid viscosity as it varies with temperature. The following must be known: The fluid type The fluid temperature at start up The fluid temperature during normal operation Other important factors are: The required fluid cleanliness target The efficiency rating of the filter Fluid Cleanliness Targets When discussing fluid cleanliness, we refer to ISO 4406 as a method of counting and quantifying contamination in a system. The chart above shows recommended ratings for common system components. Many hydraulic manufacturers publish required fluid cleanliness levels for their equipment. Guide to Filter Placement The table below can be used as a guide for filter placement in a system. Each of the blocks ...

Understanding Filtration – Temperature and Viscosity

Understanding Filtration in Hydraulic Systems When adding filtration to an hydraulic system, it’s important to understand the role of viscosity, pressure drop, fluid cleanliness and filter efficiency (beta ratios) in the overall performance of the system. Temperature is also a key factor in determining the effectiveness of hydraulic filters. What is Viscosity? Viscosity is the measure of the resistance of a fluid to deform under sheer stress. It is commonly perceived as thickness, or as a resistance to pouring. It may also be described as a fluid's resistance to flow, or a measure of fluid friction. Water has a low viscosity, and honey has a high viscosity. However, viscosity can be affected by changes in the fluid temperature. For example, when heated, honey will flow more easily. Understanding the behaviour of a fluid's viscosity is an important part of understanding filtration technology. Pressure Drop Pressure drop is a measure of how much pressure is required to push a fluid through a restriction, or 'orifice'. A filter element acts as a restriction when fluid is flowing through it. The level of ...

Who are the Type Approval Surveyors For RYCO’s products?

Approval bodies (Surveyors) RYCO works with a number of approval bodies, or surveyors, to obtain type approvals for RYCO hydraulic hose assemblies, and maintain best practice quality management system standards. Following is information about the surveyors who are currently providing type approval for RYCO products, using their own words. Marine Approval Bodies American Bureau of Shipping Mission Statement from the ABS website: "The mission of ABS is to serve the public interest as well as the needs of our clients by promoting the security of life, property and the natural environment primarily through the development and verification of standards for the design, construction and operational maintenance of marine-related facilities." DNV GL Statement from the DNV GL website: "DNV GL’s shared roots stretch back to 1864, when Det Norske Veritas (DNV) was founded as a membership organisation in Oslo and GL was formed out of a desire to achieve transparency. Today DNV GL is a globally leading quality assurance and risk management company. Driven by their purpose of safeguarding life, property and the environment, DNV-GL enables organisations to advance the safety ...

Type approvals for hydraulic hoses and fittings and why they matter

What is a Type Approval? Type Approval is granted to a product that meets a minimum set of regulatory, technical and safety requirements. Generally, type approval is required before a product is allowed to be sold into a particular country or industry sector, so the requirements for a given product will vary around the world. The requirements can also differ from industry to industry. For example, SAE J517 is a Society of Automotive Engineers standard that tells a manufacturer how to make a variety of hose products. This does not necessarily mean that a hose will automatically be able to work in that industry. It may still require a TYPE APPROVAL. Marine Approvals Marine Surveyors As maritime vessels will always work in an environment of risk, maritime insurers use marine inspectors as expert assessors to report on the condition of the vessels being insured. A marine surveyor is a person who conducts inspections or surveys of marine vessels to assess, monitor and report on the vessel's condition, and on the condition of any products that have been installed within them. ...

How to use the RYCO proof test rig – Machine Operation

In this second part of this series on impulse testing, we discuss how to use the proof test rig to safely test your hydraulic equipment set up. Machine Operation Connect the assembly Prepare the connection. Select an adaptor to suit your hose assembly and fit it to the rig. Ensure you're not damaging any thread at this point. Fit your hose assembly to the rig. Use two spanners to tighten the hex, so as to not damage any parts. NOTE: When fitting an adaptor, it is vital that the connection is leak free. When the rig creates a high pressure, it does so with a minimal amount of fluid. A small leak will limit the amount of pressure that can be produced. Purge the hose Leave the other end of the hose uncapped. Open up the High Pressure valve by turning anti-clockwise, and open up the pre-fill valve by turning it to the "'on" position. Allow the fluid to vent through the hose. Cap the hose assembly Elevating the hose will ensure that all of the air is purged from ...

How to use the RYCO proof test rig – Safety & Controls

In this first part of this series on impulse testing, we discuss the importance of safety procedures and the controls that are available on the RYCO proof test rig. Supporting Documents for the RYCO Proof Test Rig Refer to these supporting document to ensure you fully understand the process and safety measures required. RH-SWP-9 Safe Work Procedure - Proof Test Rigs RH-Wl-13 Work Instruction - Internal Proof Pressure Test SAE J343 Test and Test Procedures for SAE IOOR Series Hydraulic Hose and Hose Assemblies AS 1180.5-1999 Methods of test for hose made from elastomeric materials - Hydrostatic pressure Safe Work Procedure Before operating the machine, refer to the latest edition of RYCO Safe Work Procedure RH-SWP-9. (Step 1 - Preparation) Prior to switching on power, check the condition of the power cord to ensure that the plug is secure, that the cord is not damaged or frayed, and that a current electrical safety test tag attached. Ensure the electrical plug is securely fitted in the socket. This applies to both the Air Compressor and the Test Rig in general. If ...