Hydraulic Intake Strainers

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Fluid Power – Otherwise known as hydraulics. It is everywhere and it can be very finicky. One of the most important things to know about setting up and maintaining a proper, full functioning, robust hydraulic system is DO NOT USE AN INTAKE STRAINER.

Plugged Intake Strainer
Plugged Hydraulic Intake Strainer

First of all you should be adding oil to your reservoir through a filter because the oil you buy is not clean. Yes it will adhere to a specific cleanliness standard, but that standard is not high enough to maintain a healthy hydraulic system. Your oil should be clean in your tank and the only way that is going to happen is to start with clean oil. Filter your oil as you add it.

Now some might say they need the strainer to keep junk out of the system that falls in the tank during service. What they actually need are service technicians with work ethic. If your oil is getting contaminated, then replace it.

The idea of the intake strainer is that it is supposed to keep the dirt out of your power system. The dirt should not be there in the first place. If you cleaned your oil when you added it, and you took proper precautions to protect your oil during servicing, there will simply be no dirt.

Intake strainers are usually a 140 mesh strainer that screws onto the pump intake inside your reservoir. What it actually does in real life is increase the NPSH (net present suction head) on your hydraulic pump. This can lead to what is called cavitation. Cavitation is a sudden change in pressure resulting in small gaseous bubbles spontaneously collapsing creating supersonic shock waves within the fluid. This is never a good thing. Anyone who has a boat and has had to replace the prop on his outboard motor because it was 9 inches in diameter in the spring and is only 6 now can attest to the affects of cavitation. (yep, that is actually what did it. Notice the pitted surface on the worn edges). Cavitating a pump is one of the quickest and most effective ways to destroy it. It is not as serious in Positive Displacement pumps as it is in Centrifugal Pumps, but it is still bad.

A common situation is to be sent out on a service call for a hydraulic system that simply isn’t making power, that won’t run properly, that is blowing breakers, that is overheating, only to find that the intake strainer is plugged up. The solution to many hydraulic failures and to the prevention of such is to dispose of your intake strainer up front. They are good on paper, but terrible in real life.

Take care of your oil. Take care of your systems. Filter your oil as you add it. Use a desiccant air filter as well to keep moisture out. But that is another blog. And get rid of that intake strainer.


 

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Curing Automation Myths

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Is Automation for You? 

GUI
Simple GUI for a Sludge Dewatering Screen

Automation is a wonder and a dark art to most of the world. Even companies who have large amounts of automation within their own facilities often have misconceptions about how it works. There, for example, is a tendency to lean towards certain brand names, yet those brands are not necessarily better and are possibly more expensive. Below are five big and common myths in the market place about custom factory automation.

  1. Automation is too expensive, it costs millions.

Actually, automation is surprisingly cost effective these days. Today, computer based controllers are effective, efficient and quite reasonably priced. A simple business model for every automation project will demonstrate its quick payback time, reduced operation costs, reduced manpower and skill requirements, and increased productivity. And it is also important to remember that you don’t take and entire process and turn it into a black box solution. First you look at your obvious bottlenecks in your process and mechanize them. As you work your way through the process gradually automating more and more you start integrating them into a complete system.

For a few decades now there has been a move towards off shore manufacturing based on the super low cost of labour in third world countries. The cost of overseas labour is still cheap but the cost of shipping, of waste, of the absence of quality control, of immense orders and long wait times far out ways any up front cost reductions. There is also the issue of the environment. One of the big cost saving in many of these countries is the complete lack of environmental laws or ecological constraints. We are waking up today, finally and thankfully. The solution to pollution is NOT dilution and just because you pollute over there doesn’t mean it won’t come here. Automation is the industry standard of the 21st century.

Most process plants today are economically viable because of automation. You simply could not afford to run an oil refinery or a water treatment plant without it.

  1. Automation costs jobs.

We do not replace people; we automate tasks. The tasks we automate are the ones that are slow, costly, ineffective and inefficient. Automation frees workers to do more interesting and productive tasks. It also improve a company’s competitive position by increasing throughput and quality while reducing or nearly eliminating waste. This improves sales, improves profits and increases your business’s overall performance and shareholder equity. Automating a factory often creates more jobs as it allows the company to gain a greater market share and provide a higher quality product.

Keep it in the tanks
Keep it in the tanks

Automation, especially in the areas of monitoring, reduce or eliminate environmental compliance issues. Automated sensors and controls allow a plant to discover and mitigate problems at the onset, not after a million gallons have been released to a river or lake.

 

  1. Automation is only for big companies.

Any task or process can be automated. There is no maximum or minimum size or complexity requirement. The same rules apply to all automation; the difference is merely one of scale. Even if it’s just a single part pick-and-place or a wash-down line that needs to be timed, we can automate it to save you time and money. Sometimes it is just one task within a complex manufacturing process that is slowing down overall production; that would be the place to start automating. Maybe you just need your pumps on timers or hooked up to simple level switches or temperature probes in tanks. Small organizations can benefit from automation just as easily as large ones.

  1. This industry has been around forever so there are lots of off-the-shelf solutions.

Truly there are a lot of standard options for mechanization. And where a standard product exists, and would be an appropriate solution, I recommend its implementation. Forklifts are the prime example. They are designed to lift, move and stack pallets, yet people buy them and use them for everything but. They are only safe and efficient in the specific task they were designed for. If what you are moving isn’t a pallet, get a machine that will work better for you and save yourself time, money and frustration.

The glass industry, for example, has been around for thousands of years and yet I have worked on many custom machines for a glass processing. As each business has its niche, so does it have its individual processes. Only a few mass-produced systems are compatible with every process within an industry, leaving large gaps in every production process. A custom automation product, however, is tailored to your specific needs and designed to meet your exact requirements. And it is the system that is tailored, using economical, time tested and proven, off-the-shelf components. You can use the same PLC for controlling a primary treatment screening of residential sewage as you would for controlling a cake manufacturing line. The difference is in the application and programming.

  1. If our process changes the new machine will be obsolete.

If you look at your entire process consulting with your technicians and operators when designing your solutions, you can build in flexibility for expansion. The machine you will get will not only be based on your current need, but it will also be parametrically designed to accommodate foreseeable changes in your product or process to match market variations and changes. For example, allowing for differences in sizes of product can allow a machine to fulfil its task for decades.

With automation, the machines are always designed modularly. This is true for hard automation, flexible automation (robotics) and process automation such as water treatment or chemical plants. As new needs arise or change, new modules can be developed and integrated into the system.

Automation has so many benefits for 21st Century manufacturing and process industries. It can no longer be ignored. The cost of automating has reduced significantly over the years with the increased performance of the computers, sensors.


 

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Corrosion Issues = Planning Issues

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Corrosion is the Fruit of Poor Planning

Rusted Out Foam Chamber
Corrosion and Erosion

Corrosion & Erosion, Hand in Hand

There indeed is a desperate need for a corrosion science. We have all seen perfect, shiny new equipment quickly rot and deteriorate in the field. Put a new motor in a pulp mill and two years later you cannot even read the label on it. String in a new stainless steel spool and a little while later you have pinhole leaks at the welds. To the right you see a fire suppression foam changer on an API 650 storage tank. It is only a few years old, but out in the wind and weather, next to the ocean, it has rotted completely away. Imagine if there was a tank fire. Do you thing that foam chamber would be effective?

In many industrial processes there is a requirement for metallurgical engineers to investigate, research and develop solutions for safe handling of chemicals. In larger industrial settings there is also a need for the assistance of corrosion specialists when integrating numerous pieces of varying equipment into a process. For example if you are transporting hydrofluoric acid at 300 Celsius through a pressurized pipe, you get an expert to tell you how. For many process situations we do have regulatory bodies and industry standard associations to help us. ASME, API, NFPA etc are perfect examples.

Outside of the Extreme

There is however another facet of the corrosion game. Many corrosion issues we face daily in industry have extremely simple solutions. Most are caused by an abject failure to educate ourselves before making decisions. All that is required is a little reading. There are untold resources, free and available at your fingertips if you have Internet and can type. There are some basic consideration that can save you a fortune and a lot of pain downstream.

Common Galvanic Corrosion

galvanically corroded boltsFirst is the problem of dissimilar metals. In general this is a BAD thing. When you are forced to use contacting dissimilar metals the first thing to note is the relative nobility of the metals. The further apart that number is, the fast one of them is going to rot away. This is further exacerbated by the amount of water present, and the amount of electrolytes in that water, and the temperature. For example if you have warm municipal wastewater, with a low pH, full of various salts as it always is, travelling through a carbon steel pipe and  you need to divert it with a hose, and decide to use an aluminium cam lock fitting. (Yes I have seen that done on more than one occasion) That decision will come back to haunt you in a few weeks. I know of another example in an oil refinery where they decided to use a titanium tube bundle in a heat exchanger. The feed pipe to the exchanger was 18 inches in diameter, to give you an idea of the scale we are talking about. The shell was about six feet in diameter and about 30 feet long. They did everything right except electrically isolating the dissimilar metals. The shell of the exchanger and the pipes feeding it were carbon steel. It was not long before they had to replace the shell and ten feet of pipe on either side.

The Process Side of Things

The next notable consideration is the chemical compatibility of your materials to your process flow. There are many tables online to help. And always, and I mean always, consult chemical compatibility tables when choosing materials for piping, fittings, tanks, vessels etc. For example, did you know that ketchup will eat through PVC piping? I didn’t either until I consulted a chemical compatibility table. What goes with what, and what doesn’t are not always intuitive. Similarly, many people mistaking think that stainless steel is stainless. It is simply corrosion resistant, under certain conditions. The rejects from a Reverse Osmosis desalination system will eat through 316 SS. You would need at the very least a 2205 duplex, or preferably a 2507 super-duplex.

Operating Conditions

Then you must consider the temperature and temperature variation. And it is not just for the acceptable temperature range of the material, you must also consider the coefficient of  thermal expansion, and the relative thermal expansion coefficients when dealing with differing materials. Laminations can peal off with heating and cooling. Piping can buckle, fitting can be snapped off. I have seen it happen. And it is not just a one time thing, it might last for a couple of months, but with each temperature cycle you get fatigue building up. Then one day, on a long weekend, you get called in to clean up because a fitting broke and nobody can figure out why.

What Else?

There is also the issue of coatings. There are many corrosion resistant coatings available for different applications. Here I definitely suggest calling the experts. And supplier of coatings should have in-house experts that will recommend the best coatings for your application if you give them accurate details up front. There are also more advanced solutions like Cathodic and Impressed Current Protection. They may seem like black magic to some, but they can work wonderfully. For example, when we replace the floor on one of our crude storage tanks, we also include a Cathodic Protection and liner. This literally adds years to the life of the tank.

Then there are things like Stress Corrosion Cracking, Corrosion Under Insulation (CUI) and Hydrogen Embrittlement, and my favourite, Microbiologically Induced Corrosion (MIC). In reality, for these you might want to consult and expert.

So for basic corrosion issues, please consult the many free and available documents that can make your life, and the life of your operators and maintainers much easier. They will thank you for it. Well, maybe not but they should. And for those funky situations where the process contains odd chemicals, high pressures etc, consult an expert and save everyone a lot of grief. Remember most corrosion issues are just the fruit of planning errors.

I hope you have found this Engineers Brief to be useful and informative. There are many more to come. Please stay tuned.


 

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The Seven Habits of Highly Automatable Systems

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Automation

The insides of automation
The insides of simple automation

When we automate, we are really just mechanizing individual tasks, controlling that task with some form of computerization, and linking those tasks together in what is called system integration. So when looking at automation the first step is to identify exactly which tasks you should be mechanizing. Here is a brief list of the seven most common task attributes that immediately lend themselves to automation. Looking around your plant and your processes you will be able to use this list to quickly identify what areas you should be first considering for automation.

  1. You have a task that involves repeatability of motions. Repeatable motions are very boring for people and lead to repetitive strain injuries. This boredom leads to slower production, increased errors, and job dissatisfaction with workers. Repetition leads to complacency among workers. With this comes an marked decrease in quality and substantial increases in rejects and waste. Machines will perform repeatable tasks flawlessly and far quicker than any human leaving the workers to do more involved and interesting tasks. Machines do not get tired or bored and do not need breaks. An automated system can be relied to repeat a task flawlessly, at a prescribed speed without deviation.
  1. Task involves very high accuracy and skill levels. Even and very skilled technician cannot match the accuracy of a machine. We have put machines into service with 0.001” repeatable accuracy. Our closed loop control systems not only allow us to design to an arbitrary accuracy, it will also perform the tasks at a much faster rate than any human can. Reducing the required skill level in a factory and reducing production time are two main requirements for reducing costs and maintaining a competitive edge. The increased accuracy also speaks to higher quality and reduced waste. As well, the higher accuracy will provide you with a superior product in the market place greatly improving your positioning.
  1. Task involves danger. A machine can be programmed to operate within a very specific range of motion. If the task is within a dangerous environment, whether heat, or chemical or dangerous moving parts, a machine is a far simpler and safer method of completing a task than trying to outfit and train a person to perform the same task safely. The automated system can be programmed to stay within a safe physical envelop and be constructed of materials that will withstand the required environment.
  1. Task involves high manpower and time. Every process has a bottleneck, and that bottleneck is usually a manpower or resources issue. Mechanizing and automating tasks or procedures within a process can effectively debottleneck an entire process and often substantially increases productivity while reducing costs. Automation is particularly useful where short run, high throughput is required.
  1. Task involves excessive handling. Material handling is often a slow, resource consuming issue and the more a product is handled the greater the danger of damage to the product and injury to the workers. Material handling has been a standard area of automation for many years but with the advancements and reduced costs of modern computerization, material handling has become a first step in plant automation in most factories. Material handling also comes into play in buffering processes to compensate for variations in production from complimentary processes. When job A feeds into job B and job A varies so you have to keep a small stockpile of goods in order to keep job B running, an automated system is a perfect solution. It will receive parts as they come and feed job B as it is needed and never need human intervention.
  1. Requirement for accurate inspections. Mechanizing and automating your inspection station will assure that you will turn out a far more standardized product with zero rejects going out to your customers. We can design and build equipment that will inspect for colour, clarity, shape, weight, size, texture or dimensions. Modern machine vision has the capability of sampling up to 500 frames per second and can differentiate up to 16 million different colours, which is more than the human eye can discern. Other testing can also be incorporated like for example using ultrasonics to test for cracks in a casting. If you have a specific inspection category, we can automate it.
  1. Offshore competition. Sadly, offshore competition can produce products far cheaper than we can in North America using traditional manufacturing methods. That is, however beginning to change with the high cost of transportation and the high material cost from the waste generated through this method. We can command a competitive edge by mechanizing and automating our processes. Machines allow us to substantially increase our production rates, decrease costs through reduced waste and manpower, and produce a more standardized, higher quality product with far fewer rejects.

It seems simple because it is. Do you have tasks or processes within you plant you need mechanized and automated? Call us, we can help. That is what we do.


 

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