New hydraulic Website www.hydraulicbrain.com
I have just launched a new website that will diagnose hydraulic problems in an interesting and novel way. www.hydraulicbrain.com.
I would like to thank Neil Dawson for the fantastic job done in producing everything I asked and hoped for, on time and at a superb price.
Thanks again Neil and I will recommend you to all who know me. amit.kum.rout@gmail.com
I would be most greatful if anyone from our group would take a look and send me their comments, opinions and how I might improve on what we have done so far.
Many thanks
Bob
Tuesday 26 April 2011
Sunday 17 April 2011
Hot Systems
Whenever I check out a hydraulic system my first reaction is to cautiously touch the side of the tank.
If I can comfortably keep my hand on the side I know that the system is running at a good temperature 20-30C (50-60Cmaximum). If my hand recoils due to the high temperature I know straight away that there is a potential problem.
Hot oil causes all sorts of problems and affect, seals, oil viscosity, oil degradation and the danger of scalding.
Ensuring that the system is running at the right temperature should be done at the drawing board stage and not tagged on later as an afterthought.
Things to consider are:
Installed Power
Duty cycle
Ambient temperature
Size of tank
Heat comes from the inefficiency of the system. If we do not use all the energy we are generating in doing work the rest will be converted into heat. Conversely, you will not generate any more heat than the maximum power of the prime mover.
Relief valves are the prime source for heat generation and if possible the system should be designed to minimise the length of time oil passes over this valve. Open centre control valves, pressure compensated pumps and unloading valves can help.
Some heat is radiated by the tank and can often remove the need for a cooler.
This is a huge subject, ranging from the damage heat can cause to the best types of coolers and I know that there are many in our group who will have some very interesting views on this subject.
Cheers
Bob
If I can comfortably keep my hand on the side I know that the system is running at a good temperature 20-30C (50-60Cmaximum). If my hand recoils due to the high temperature I know straight away that there is a potential problem.
Hot oil causes all sorts of problems and affect, seals, oil viscosity, oil degradation and the danger of scalding.
Ensuring that the system is running at the right temperature should be done at the drawing board stage and not tagged on later as an afterthought.
Things to consider are:
Installed Power
Duty cycle
Ambient temperature
Size of tank
Heat comes from the inefficiency of the system. If we do not use all the energy we are generating in doing work the rest will be converted into heat. Conversely, you will not generate any more heat than the maximum power of the prime mover.
Relief valves are the prime source for heat generation and if possible the system should be designed to minimise the length of time oil passes over this valve. Open centre control valves, pressure compensated pumps and unloading valves can help.
Some heat is radiated by the tank and can often remove the need for a cooler.
This is a huge subject, ranging from the damage heat can cause to the best types of coolers and I know that there are many in our group who will have some very interesting views on this subject.
Cheers
Bob
Sunday 10 April 2011
Suppliers get 90% of our orders wrong!
All the financial experts are saying that the small amount of manufacturing we still have is picking up and no one can be more pleased to hear that than me. But with this welcome successes comes other problems.
In my business and I dare say many other similar businesses are now suffering long delivery or poor quality issues. I would go even further and say that 90% of the orders we place with suppliers we are either told the parts are no longer available, have long delivery times or just comes in wrong!
These days many components are not made in the Uk and we are reliant on overseas manufacturers. Anything we need from Germany and I’ll bet it will be as difficult to get as hen’s teeth and a big price tag to boot. When the world’s economies pick up it is not surprising that manufacturers look after their home markets first. Although we can now get some of those important orders we craved, it is the delivery issues that are letting us down and disappointing our customers.
What I find most frustrating is when orders come in wrong either due to poor workmanship or simply the sales guy has not paid proper attention to my needs. Recently, after waiting 3 weeks for my supplier to deliver some urgent parts and continuous chasing by phone and email he admitted that he had forgotten to place the order on his factory floor.
If we are to get serious again about Manufacturing we must get it right. Saying sorry is just not good enough and does not excuse sloppy service and it will certainly not get us back as a serious world competitor. We also need to be more self sufficient in obtaining simple parts to prevent hold ups, improve our cash flow and make us more price competitive.
To do that of course we must also have stability and continued commitment from our Government to ensure we get the investment in skills and equipment for the long term, and then hopefully this resurgence will not be just a flash in the pan.
Cheers
Bob
In my business and I dare say many other similar businesses are now suffering long delivery or poor quality issues. I would go even further and say that 90% of the orders we place with suppliers we are either told the parts are no longer available, have long delivery times or just comes in wrong!
These days many components are not made in the Uk and we are reliant on overseas manufacturers. Anything we need from Germany and I’ll bet it will be as difficult to get as hen’s teeth and a big price tag to boot. When the world’s economies pick up it is not surprising that manufacturers look after their home markets first. Although we can now get some of those important orders we craved, it is the delivery issues that are letting us down and disappointing our customers.
What I find most frustrating is when orders come in wrong either due to poor workmanship or simply the sales guy has not paid proper attention to my needs. Recently, after waiting 3 weeks for my supplier to deliver some urgent parts and continuous chasing by phone and email he admitted that he had forgotten to place the order on his factory floor.
If we are to get serious again about Manufacturing we must get it right. Saying sorry is just not good enough and does not excuse sloppy service and it will certainly not get us back as a serious world competitor. We also need to be more self sufficient in obtaining simple parts to prevent hold ups, improve our cash flow and make us more price competitive.
To do that of course we must also have stability and continued commitment from our Government to ensure we get the investment in skills and equipment for the long term, and then hopefully this resurgence will not be just a flash in the pan.
Cheers
Bob
Sunday 3 April 2011
Hydraulic Circuit Conventions
Fault finding hydraulic systems can be difficult but much harder without the benefit of an accurate circuit diagram.
Many systems are very simple, a pump, relief and directional control valve. This is straight forward and easy to follow but more complex systems with large manifolds can be almost impossible without the benefit of a circuit.
To the un- initiated eye, circuit diagrams can look like something written by a creature from a distant planet but circuit diagrams and symbols are quite easy to understand.
I always say to students that hydraulic symbols are similar to road signs and will resemble the components it represents. (a spring looks like a spring, a flow path an arrow)
What I find irritating and most annoying is when I pick up a circuit drawing that has come from a well known International hydraulic company that have symbols I do not recognise or maybe a Relief valve drawn instead of a Reducing valve. I even see symbols that have been made up, created and nothing I have ever seen in ISO or CETOP standards.
Many of us would not be particularly fazed by a Relief Valve being misplaced by a Reducer because of it’s the location in the circuit. but on my complex circuits, non standard symbols can be confusing and result in a lot of head scratching and wasted time.
Like any engineering drawing, circuit drawings should be clear, unambiguous and follow proper International standards. If we all start designing own symbols and drawing circuits without proper convention it could at best be more confusing and at worst cause serious accidents. Employers should ensure that their engineers are doing things right and setting standards that we can all understand.
I would love to hear your views; maybe you have misread a drawing?
Cheers
Bob
Many systems are very simple, a pump, relief and directional control valve. This is straight forward and easy to follow but more complex systems with large manifolds can be almost impossible without the benefit of a circuit.
To the un- initiated eye, circuit diagrams can look like something written by a creature from a distant planet but circuit diagrams and symbols are quite easy to understand.
I always say to students that hydraulic symbols are similar to road signs and will resemble the components it represents. (a spring looks like a spring, a flow path an arrow)
What I find irritating and most annoying is when I pick up a circuit drawing that has come from a well known International hydraulic company that have symbols I do not recognise or maybe a Relief valve drawn instead of a Reducing valve. I even see symbols that have been made up, created and nothing I have ever seen in ISO or CETOP standards.
Many of us would not be particularly fazed by a Relief Valve being misplaced by a Reducer because of it’s the location in the circuit. but on my complex circuits, non standard symbols can be confusing and result in a lot of head scratching and wasted time.
Like any engineering drawing, circuit drawings should be clear, unambiguous and follow proper International standards. If we all start designing own symbols and drawing circuits without proper convention it could at best be more confusing and at worst cause serious accidents. Employers should ensure that their engineers are doing things right and setting standards that we can all understand.
I would love to hear your views; maybe you have misread a drawing?
Cheers
Bob
Saturday 2 April 2011
Designing for the environment
Drawing a hydraulic circuit and working out the sizes for pumps, valves and actuator are very important but not the beginning and end all. Just as important is where the equipment will be used and the environmental implications of the design.
Foundries and steel mills can be very dirty places and also not a place where you want a hose to burst, spraying hydraulic oil across molten metal.
Any system close to the sea, on a boat or oil rig will suffer from high levels of corrosion. Maybe you should be thinking of stainless steel pipe-work or epoxy painted surfaces. Also boats and mobile equipment might prefer smaller oil reservoirs and closed circuit pumps.
The yacht enthusiast are very concerned about weight, again watch out for large oil tanks.
Consider special materials, titanium, aluminium and carbon fibre and it might even be that the system must be able to work upside down without spillage!
Mobile equipment often needs to be light. Rams might have to be smaller with higher pressure to achieve the same forces..
Many industries like heavy duty, robust equipment that can be abused. Watch out for vulnerable components like electronic instruments. (Transducers can be fitted inside the rams)
Hydraulics used in some environments must not spill mineral oil onto water or the soil. Consider synthetic environmental friendly oils.
There are some applications where noise is a problem. Film sets and close proximity to public places that are very sensitive noise. Using quieter pumps, hydraulic hose, accumulators and attenuators might be an option.
If you are designing a system to be used in a hot environment with very high ambient temperature or humidity. Sometimes water cooling is just NOT an option.
In summary, I am saying that there are many different levels of a hydraulic design and they all have equal importance. The environment can be crucial to the success or failure of your design. Ignore it at your peril!.
I would love to hear about your views or any stories you might have where the environment was a major issue.
Cheers
Bob
Foundries and steel mills can be very dirty places and also not a place where you want a hose to burst, spraying hydraulic oil across molten metal.
Any system close to the sea, on a boat or oil rig will suffer from high levels of corrosion. Maybe you should be thinking of stainless steel pipe-work or epoxy painted surfaces. Also boats and mobile equipment might prefer smaller oil reservoirs and closed circuit pumps.
The yacht enthusiast are very concerned about weight, again watch out for large oil tanks.
Consider special materials, titanium, aluminium and carbon fibre and it might even be that the system must be able to work upside down without spillage!
Mobile equipment often needs to be light. Rams might have to be smaller with higher pressure to achieve the same forces..
Many industries like heavy duty, robust equipment that can be abused. Watch out for vulnerable components like electronic instruments. (Transducers can be fitted inside the rams)
Hydraulics used in some environments must not spill mineral oil onto water or the soil. Consider synthetic environmental friendly oils.
There are some applications where noise is a problem. Film sets and close proximity to public places that are very sensitive noise. Using quieter pumps, hydraulic hose, accumulators and attenuators might be an option.
If you are designing a system to be used in a hot environment with very high ambient temperature or humidity. Sometimes water cooling is just NOT an option.
In summary, I am saying that there are many different levels of a hydraulic design and they all have equal importance. The environment can be crucial to the success or failure of your design. Ignore it at your peril!.
I would love to hear about your views or any stories you might have where the environment was a major issue.
Cheers
Bob
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