Installing Hose Assemblies II

Review the Safety Precautions found in previous blog posts about “Maintaining a Safe Work Environment” as well as your equipment’s operations manual before installing hydraulic hose assemblies. Installation varies depending on coupling configurations, use of adapters, and routing.

Coupling Configurations

Male fitting to port connections can be made using four types of configurations:

§  Solid male (MP, MB, MBSPT, etc.).

§  Male swivels (MPX, MBX, MIX).

·         Flanges (FL, FLH, FLC, FLK).

·         Block-style adapters with Lock- nuts.

Male Swivel

Male swivel installation does not require hose rotation.  Install the male thread into the port and use a wrench to torque properly.  Orient the hose curvature to assist in routing, since the hose does not rotate.  Male swivels (except MIX) have internal O-rings that must be compatible with the fluid used.

Installing Hose Assemblies I

Review the safety precautions found in previous blog posts about “Maintaining a Safe Work Environment” as well as your equipment’s operations manual before installing hydraulic hose assemblies. Installation varies depending on coupling configurations, use of adapters, and routing.

Coupling Configurations

Male fitting to port connections can be made using four types of configurations:

§  Solid male (MP, MB, MBSPT, etc.).

§  Male swivels (MPX, MBX, MIX).

      ·         Flanges (FL, FLH, FLC, FLK).

·         Block-style adapters with Lock- nuts.

Solid Male

Solid male fittings are installed by rotating the entire hose assembly when the male thread is threaded into a port. For ease of installation and improved seal, Teflon® tape can be used on tapered threads.

If an O-ring is used, lubricate it with oil before installation. A poor seal can be the result of a dry O-ring sticking and pulling away from the sealing area.

Once hand-tight, use a wrench on the hex to properly torque the fitting. Since hose rotation is necessary, never use two solid males on the same hose assembly.

 

  

Maintaining a Safe Work Environment - Electrical V

Establishing a safe working environment in and around your hydraulic equipment requires a few things you must be aware of.  These include:

·         Pressure

·         Temperature

·         Flammability

·         Mechanical

·         Electrical

Electrical

Hydraulic equipment should always be turn off before starting to do work on the equipment.   Prior to working on any plant equipment, lock the control box, and tag it with a warning sign that states “DOWN FOR MAINTENANCE. DO NOT TURN ON POWER.”   If the equipment is mobile, take the key and/or disconnect the battery cables from the battery so the equipment can’t be started.

During normal equipment operation, you may be exposed to electrical hazards such as high-voltage power lines and underground power sources. Always identify these potential hazards before running the equipment. 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. Some equipment requires the use of non-conductive hose if there’s a chance of contacting power sources.

OSHA standards require that all hydraulic tools used on or near energized power lines or equipment be supplied with non-conducting hose having adequate strength for normal operating pressures [29 CFR 1926.951(f)(3)].

Faulty wiring can also be an electrical hazard. A regular preventive maintenance program should always include a wiring check.

Maintaining a Safe Work Environment - Pressure IV

Establishing a safe working environment in and around your hydraulic equipment requires a few things you must be aware of.  These include:

·         Pressure

·         Temperature

·         Flammability

·         Mechanical

·         Electricity

Flammability

All hydraulic fluids (including fire resistant hydraulic fluids) are flammable when exposed to the proper conditions.  Exceptions are those fluids comprised primarily of water.

Systems leaking pressurized hydraulic fluids that develop a mist or fine spray that come in contact with a source of ignition can flash or explode. These very severe explosions can cause serious injury or death.

Precautions should be taken to eliminate all ignition sources from contact with escaping fluids, sprays or mists resulting from hydraulic failures.  Sources of ignition could include electrical discharges (sparks), open flames, extremely high temperatures, hot manifolds, engine blocks, and sparks caused by metal-to-metal contact.

Mechanical

Unexpected mechanical motion can be dangerous. Watch out for swinging arms, booms, rollers, or presses.  Anything that moves can be dangerous if a hose fails. For example, when a hose bursts, objects supported by fluid pressure may fall and vehicles or machines could lose their brakes because of pressure loss.

Maintaining a Safe Work Environment - Pressure III

Establishing a safe working environment in and around your hydraulic equipment requires a few things you must be aware.  These include:

·         Pressure

·         Temperature

·         Flammability

·         Mechanical

·         Electricity

Pressure

Operating pressures of hydraulic systems can be up to 10,000 psi.

The dangers that could be encountered with hydraulic fluid under pressure include:

Whipping Hose:  If the hose end or end fitting comes apart under pressure, the loose hose can whip around with great force. This has the potential to cause serious injury. Restrain or shield the hose using clamps or protective shielding if this hazard exists.

Stored Energy: Hydraulic systems sometimes use accumulators to store potential energy or absorb shock. This energy can create pressure that keeps the system’s components moving.

Temperature

Hydraulic systems typically operate at 150° to 180°F, but hydraulic systems can go as high as 300°F. Liquid at these temperatures may burn skin. Metal parts (such as fittings and adapters) are also hot and may cause burns. Hoses can also become hot.

Hose Cleanliness – Methods of measurement Part 3

There are three principal methods to measure the contamination level in a component, circuit, or system. The methods are Gravimetric Measurement (ISO 4405); Particle Size Distribution Analysis (ISO 4406 or NAS 1638); Maximum Particle Size Analysis (ISO 4407).

Maximum Particle Size Analysis (ISO 4407)  

This evaluation is done using a microscope. A microscope is used to identify and measure the size of individual pieces of contaminant. Particle size is important in reference to maximum clearances of hydraulic components.

Whether hydraulic assembly cleanliness applies to you or not, it is worthwhile to understand the significant impact that contamination levels can have on the life of hydraulic system components.

Implementing a thorough cleanliness system may have a significant impact on warranty returns for hydraulically powered equipment.

Hose Cleanliness – Methods of measurement Part 1 - Gravimetric Measurement

There are three principal methods to measure the contamination level in a component, circuit, or system.

The methods are: Gravimetric Measurement (ISO 4405); Particle Size Distribution Analysis (ISO 4406 or NAS 1638); Maximum Particle Size Analysis (ISO 4407).

 

This discussion will cover Gravimetric Measurement.

Gravimetric Measurement (ISO 4405) is a reporting method that references the total mass of

contaminant found in a hydraulic component. This total mass of contaminant measurement is then normalized by the total internal component surface area of a hydraulic component. A fluid is used to

dislodge contamination in a hose assembly and is then poured through a membrane catch filter.

An analytical balance is used to measure the total mass of contaminate which has been flushed out of a component. The total mass of contaminate and is referenced to the surface area or volume of the assembly.

Gates currently offers a system of four Gravimetric measurement (ISO 4405) levels of cleanliness for hydraulic assembly that can be used to meet or exceed cleanliness requirements.