Wednesday 23 September 2009
Casting Machine Hydraulics
WH Rowe Ltd is a Foundry in Southampton producing high quality Aluminium Castings. They have been a very good customer for many years and I sincerely thank them for their continued support and allowing me to produce this video.
Saturday 19 September 2009
Friday 18 September 2009
Sunday 13 September 2009
Wednesday 9 September 2009
Some Hydraulic Safety Tips
Accidental start up.
Before starting work always ensure that the machine you are working on is switched off.
Never rely on other people to keep you safe. If possible keep the emergency stop key in your pocket or ask a qualified electrician to remove the machines fuses.
A clear sign informing others that you are working on the machine should be displayed. Surround the area with hazard tape.
A system with potential (stored) energy.
Ensure that the system is not pressurized and accumulators are fully discharged before removing any hydraulic part.
Check for any suspended or external loads on rams or motors. i.e. cranes, winches and lifts. Always lower the load to remove any locked pressure. If it’s not possible to lower the load, ensure that the load is safely chocked with suitable load bearing material (timber).
Sometimes it is not always obvious that there is an external load. Consider a vehicle with a hydraulic drive parked on a hill. Removing a component could release the locked pressure and set the vehicle in motion.
And remember, It’s not advisable to walk or stand under any suspended load, hydraulics can fail!
What Pressure?
It is important to know the pressure of the system you are working on. Sometimes you will find a label on the power pack or hydraulic circuit stating the maximum pressure. Any replacement parts should always be suitable for the pressure that it is being used for. Pressure gauges should have a scale twice the pressure being measured. If you have a maximum pressure of 250Bar a 500 Bar gauge or greater should be used.
Never try to find oil or air leaks using your hand as this can cause serious injury.
High pressure can be very dangerous but even low pressure when applied to a ram can exert very high crushing forces. Remember that Force = pressure x area, the larger the area the higher the force!
Hydraulic Oil.
Most hydraulic systems use mineral based oil which incorporates additives to improve the system performance and longevity of the components. It is important to use gloves or good barrier creams to help reduce contact with the skin and safety glasses to protect your eyes.
Special oils for extreme temperatures can sometimes be very aggressive and should be handled with care. When handling this type of fluid it is important to follow the manufacturer’s safety recommendations.
Always keep your work area clean and free from oil spills. Oil on the floor is extremely dangerous and can cause people to slip over.
If oil is ingested or injected through the skin immediately seek medical attention and provide medics with details of the fluid.
Bleeding the system.
It is rare that hydraulic systems need bleeding; however there are times when trapped air can cause erratic movements.
Air bleeds are sometimes fitted to hydraulic cylinders or located somewhere in the hydraulic circuit.
Most bleeds are designed to be captivated and should not unscrew completely from its housing but this should never be assumed or taken for granted. When releasing trapped air always stand to one side of the air bleed. Should the bleed unscrew from its housing you must not be in its line of trajectory. People have been killed by being in the way of bleed screws released under pressure.
QUICK CHECK
· Has the machine been disabled
· Do you have key or fuses in your pocket
· Is there clear signage with hazard tape
· Have you discharged accumulators
· Have you removed all loads from rams or motors?
· Can the machine run away (wheel motors)
· What is the maximum pressure of the system
· Do you know what oil is being used COSH details
· Do you have gloves/barrier cream
· Are you wearing safety spectacles
· Do you have products for keeping area free of oil
· Are bleeds fitted remember stand to one side!
Before starting work always ensure that the machine you are working on is switched off.
Never rely on other people to keep you safe. If possible keep the emergency stop key in your pocket or ask a qualified electrician to remove the machines fuses.
A clear sign informing others that you are working on the machine should be displayed. Surround the area with hazard tape.
A system with potential (stored) energy.
Ensure that the system is not pressurized and accumulators are fully discharged before removing any hydraulic part.
Check for any suspended or external loads on rams or motors. i.e. cranes, winches and lifts. Always lower the load to remove any locked pressure. If it’s not possible to lower the load, ensure that the load is safely chocked with suitable load bearing material (timber).
Sometimes it is not always obvious that there is an external load. Consider a vehicle with a hydraulic drive parked on a hill. Removing a component could release the locked pressure and set the vehicle in motion.
And remember, It’s not advisable to walk or stand under any suspended load, hydraulics can fail!
What Pressure?
It is important to know the pressure of the system you are working on. Sometimes you will find a label on the power pack or hydraulic circuit stating the maximum pressure. Any replacement parts should always be suitable for the pressure that it is being used for. Pressure gauges should have a scale twice the pressure being measured. If you have a maximum pressure of 250Bar a 500 Bar gauge or greater should be used.
Never try to find oil or air leaks using your hand as this can cause serious injury.
High pressure can be very dangerous but even low pressure when applied to a ram can exert very high crushing forces. Remember that Force = pressure x area, the larger the area the higher the force!
Hydraulic Oil.
Most hydraulic systems use mineral based oil which incorporates additives to improve the system performance and longevity of the components. It is important to use gloves or good barrier creams to help reduce contact with the skin and safety glasses to protect your eyes.
Special oils for extreme temperatures can sometimes be very aggressive and should be handled with care. When handling this type of fluid it is important to follow the manufacturer’s safety recommendations.
Always keep your work area clean and free from oil spills. Oil on the floor is extremely dangerous and can cause people to slip over.
If oil is ingested or injected through the skin immediately seek medical attention and provide medics with details of the fluid.
Bleeding the system.
It is rare that hydraulic systems need bleeding; however there are times when trapped air can cause erratic movements.
Air bleeds are sometimes fitted to hydraulic cylinders or located somewhere in the hydraulic circuit.
Most bleeds are designed to be captivated and should not unscrew completely from its housing but this should never be assumed or taken for granted. When releasing trapped air always stand to one side of the air bleed. Should the bleed unscrew from its housing you must not be in its line of trajectory. People have been killed by being in the way of bleed screws released under pressure.
QUICK CHECK
· Has the machine been disabled
· Do you have key or fuses in your pocket
· Is there clear signage with hazard tape
· Have you discharged accumulators
· Have you removed all loads from rams or motors?
· Can the machine run away (wheel motors)
· What is the maximum pressure of the system
· Do you know what oil is being used COSH details
· Do you have gloves/barrier cream
· Are you wearing safety spectacles
· Do you have products for keeping area free of oil
· Are bleeds fitted remember stand to one side!
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