• Publication Date: 06/01/2021
  • Author(s):
    Smith, Todd
  • Organization(s):
    K-State Bulk Solids Innovation Center
  • Article Type: Technical Articles
  • Subjects: System or equipment design, fabrication

Todd Smith | K-State Bulk Solids Innovation Center

Project engineers are often asked to select vendors and work with them to install new equipment. These projects can have a long-lasting impact on the success of the company and the engineer’s career. This two-part article describes how to successfully work with an equipment supplier. Part I of this article provides suggestions, along with dos and don’ts, to help make choosing and working with a vendor successful. Part II explains the necessary project services that go along with building your system and describes how to choose a vendor.

Finding an equipment vendor for your powder and bulk solids application isn’t as simple as finding a car salesperson to help you purchase a new car. Material handling and processing systems are complex and can be even more so depending on the material involved. There are a number of factors to consider when selecting an equipment vendor, including your project’s goals, your material’s properties, the vendor’s proven experience, and other project services you may need. This article will address these factors and provide a number of guidelines to help you purchase equipment from the best supplier.

Why is this important?

Making a capital equipment purchase is a big investment and commitment. In addition to the up-front cost, the decision can affect the company’s performance for many years to come and impact product quality, system reliability, and operating costs. Furthermore, it’ll directly affect your quality of life: a system that performs well will make you look good and let you move on to other projects. In contrast, equipment or a system that performs poorly will keep you involved until it performs better. Working with poorly operating equipment makes everyone unhappy, so it’s worth your while to invest effort up front to avoid issues.

Before you begin talking to vendors

When starting any project, you should first clarify the goals. Why are you doing this project? What do you want to achieve? Are you making old equipment more reliable or expanding your capacity? Other possible goals include improving product quality, lowering energy or operating costs, or reducing emissions. For the best results, share this information with your vendor — if your goal is to improve flexibility with quick material changeovers, they’ll design the equipment differently than they will if you’re trying to maximize throughput.

Your goals should be realistic. One experienced project engineer told me, “You have to decide between speed, low cost, or high quality. Choose any one or two because we can’t do all three in the same project.” Accordingly, like most engineering work, the project decisions will be a set of compromises — you have to choose which parameters are critical and which ones can be compromised.

Establish and understand the project constraints. Is there a realistic budget and timeline? Don’t forget other factors such as material quality specifications, environmental regulation compliance or permitting requirements, noise level limits, and personnel safety. Alternately, you may have physical plant restrictions, such as head-height or floor-space limits, or you may need to squeeze new equipment through doorways or between other equipment. Regarding project timing, you may be locked into a specific shutdown time or seasonal slowdown. You need to understand and list all of these constraints, then share the information with your vendor.

Detailed spec or loose spec?

You’ll need to decide whether to dictate all the project details in a specification (spec) or leave much of it up to the vendor. You always need to provide basic information, so consider all the points listed in the sidebar titled “List of information your vendor will need.” But how much information you dictate beyond that will have a large impact on the rest of the project and its cost.

Detailed specs are good if you know exactly what you want and you want all vendors to bid it the same way. Dictating details will be easier if you’re experienced, you understand how the process will operate, and you know what type of equipment you want. Specs are also important if the process is complicated and the new equipment will affect other aspects of the process. Beware, however, of just copying an old spec — you may end up paying more because it includes things that aren’t critical in your project or ignores equipment advancements that have been made since the spec was written. If you do use an old spec, go through it in detail to make sure each point is valid and pertinent to the current project. Most importantly, be aware that if you specify any equipment models or sizes, then you’re moving that equipment’s performance responsibility to yourself rather than the vendor.

On the other hand, rather than providing a detailed spec, you may not need to include any information other than that listed in the sidebar. In other words, you tell the vendor about the system’s required outcome and limitations and then let the vendor choose the equipment concept and sizes. This puts the responsibility on them if there are any problems. In addition, a loose spec allows the vendor to choose equipment that’s closer to their standard rather than customizing it to your spec. That can save you a lot of money, but you need to make sure their offering still meets all your project and reliability goals!

A good compromise for you, as the project manager, is to provide detailed information in a spec but invite the vendor to suggest alternatives. Another good option is to ask an independent industry or university consultant to help develop the spec.

List of information your vendor will need

Whether you provide your vendor with a detailed spec or let them fill in the blanks, you’ll need to give your vendor some information to get the equipment-­selection process off the ground. The following is a list of the minimum information your vendor will need.

1. Material information. To start, the vendor will need to know your application’s material product name and description. If you’re asking for a budgetary proposal, then a few material properties, such as bulk density and particle size, should suffice. But if you want a firm proposal with a process guarantee, then be prepared to send a material sample to each potential vendor or send a sample and get results from an independent test facility.

2. Environmental parameters. The vendor will need to know the city and state or country in which the equipment will be located. What’s the location’s elevation? Are there summer and winter design factors that’ll apply to the equipment? Will the equipment be indoors or outdoors? Silos and structures will need wind loading and seismic zone data.

3. Site parameters. The vendor will need details about electrical power and other utilities, area hazard classifications, noise or other limits of that nature, and washdown or cleaning requirements. If your system includes explosion venting, then the vendor will also need to know the distance to an acceptable exterior wall.

4. System parameters. The vendor will need to know the system’s throughput rate, capacities, and size limits. For conveying systems, the vendor will need vertical and horizontal distances and number of bends, and for storage systems, they’ll need capacities and space restraints.

5. Equipment details. The vendor will also need to know equipment details such as the construction material for material-contact and non-material-contact surfaces. What are the acceptable gaskets or coatings if applicable? Does your equipment require any welding and surface-finish or hygienic standards? What about insulation or heat tracing?

6. Performance expectations. Your project goals, system parameters, and product quality requirements will be used to establish your criteria for the vendor’s performance targets.

7. Process flow diagram. A process flow diagram, even if it’s a crude sketch, is your best communication tool! This diagram shows the project’s general process flow and equipment.

Material information and samples

We all know that handling and processing powders and bulk solids can be difficult. Designing equipment and systems for bulk solids is more challenging than designing for liquids or gases since powder handling models are less defined and material properties can change throughout the process. Therefore, smooth startups are less common, and project problems seem to linger longer.

For the best chance of project success, tell your vendor as much as you can about the material you’ll be working with. Even for a budgetary quote, you’ll need to provide the material name, bulk density, and particle size. A good option is to work with an independent lab to determine which material properties are relevant for the project, have them do the tests, and send the results to your vendor. Independent labs charge a few hundred dollars per test. Alternately, you can send a sample to each vendor and let them perform the tests. They test only the parameters they need, and they typically don’t charge for testing if they think you’ll be buying equipment. In any case, use good sampling techniques to obtain a sample that’s representative of the material to be handled in production.

After the equipment is up and running in your facility, vendors may grasp at any variation in the bulk solids material condition as an excuse if there are any problems achieving target performance (as opposed to blaming any problems on the equipment). So be sure to include all the materials and conditions that need to be handled in the system, and consider changes that occur throughout the process as the material moves from one piece of equipment to the next. Sometimes material supplier, process, or production changes introduce significant material variations not included within the original system design. Accordingly, it’s good to secure prior agreement about the options available and steps to be taken should the production material condition be a little different than the original samples or properties.

Do you want to buy the entire system from one supplier or buy components and put it together yourself?

Early on, you’ll need to determine the extent of each vendor’s scope of supply, which are the goods and services to be delivered or performed under the purchase order. If you’re buying more than one piece of equipment, will it be better to get it all from one vendor or should you purchase the components individually and integrate the system yourself? Each method has some advantages and disadvantages.

It’s likely that no supplier will manufacture all of the equipment and components you need in a system. Fortunately, many system suppliers are good at using their own items when appropriate and integrating equipment from other suppliers as needed. How do you know which type of company is the best one to supply the system you want? Often, you’ll want to choose the one with a majority of the scope and let them provide all the ancillary equipment. Conveying companies, for example, don’t make every system component, but they’re good at integrating a nice variety of equipment from other suppliers who specialize in level indicators, storage silos, feeders, relief valves, motors, and so on. On the other hand, if your process depends on a critical piece of equipment, such as a mixer or extruder, you may want more control of that item since it’s the part of the system that adds value to your material. In that case, you may want to buy that equipment directly from its supplier even if you buy everything else from a different system supplier.

There is a trade-off in allowing a vendor to pick your system’s equipment and components. The good news (for you) is that letting a vendor be the system integrator makes them responsible for ensuring that everything will work together. That requires some work and adds performance responsibility to the integrator; therefore, they rightfully add some money to your project costs. Typically, they’ll add 35 to 50 percent to their purchase price for complicated or critical items, such as a sifter; they’ll add 15 to 40 percent to the price of commodity items, such as pipes; but they’ll add only 10 to 20 percent for expensive but low-risk items, such as silos. They earn the markups by figuring out the details, assuming the system performance risk, and having the knowledge to make it all work together.

If you want to save money, you can pull components out of the primary vendor’s system scope and buy them directly from the manufacturer. Doing it yourself is more work, is less convenient, and works well only if you have experience. Furthermore, it adds process risk because if the items work separately but not together, then it’s your fault. If you purchase individual components yourself, attention to detail is necessary. Especially at all interface points where any two items are connected, make sure all aspects fit together mechanically and electrically and that there’s no interference with structures, vibrations, electrical grounding, and the like.

Another guideline is to look at where a piece of equipment fits in the system. If it’s in the middle of the system and affects the system’s performance, such as an inline sifter or metal separator, then it’s probably best to include that in the system supplier’s scope. But if the piece of equipment is at the very beginning of the system (such as a bulk bag unloader) or at the very end (such as bin vent filter), then there’s less risk in pulling that item out of the system supplier’s scope and supplying it separately.

If you want to reduce the number of spare parts you have to stock at your plant, then it’s okay to dictate specific models or brands of replacement items, such as solenoid valves, motors, and filter elements. But be aware that you’ll pay more up front since the supplier has to re-engineer their product to match your requirements and they’ll have to pay more because they lose the purchasing clout that they get from their normal sub-supplier.

On the other hand, you can often save money in the long run if you buy a set of spare parts up front as part of the original capital purchase. That’s because suppliers make a lot of money when they apply a high markup on spare parts sold down the road. But if you add the spare parts to your project budget and buy them up front as part of the project scope, then you can take advantage of the competitive pricing that occurs with the original purchase. Just make sure that the supplier doesn’t use up the spare parts during their commissioning of the project!

Specific items that are sometimes removed from the system supplier’s scope

Sometimes, you can save money by removing certain components or services from the system supplier’s scope and providing them separately. The most common things to remove are controls, piping, and support structures because they can be built in-house or bought from a separate supplier. Before you do so, however, be aware of the pluses and minuses.

Controls: Most system suppliers have good capability to supply PLC controls and motor control centers. If they do this in-house, their software is less expensive because they have done it many times before, whereas supplying these controls may be new to your control group. The supplier’s program code will usually have fewer startup issues for the same reason. Complicated and critical process equipment, such as extruders and some dryers, may have their own PLC or microprocessor controls that work well at a fair price. Whenever possible, make sure that you receive and own the control code; some control companies want to retain it so that you have to go back to them if you ever want to change anything in your process.

Pipes, couplings, and elbows: If you’re buying a pneumatic conveying system, you can save money by purchasing these commodity items yourself. The good news is that it’s easy to get the right component as long as you understand various specifications of pipe thickness, pipe versus tubing, bend radii, and coupling types. However, be aware of the disadvantages. Primarily, it takes some time and effort to choose the right components. If quantities are wrong, then either you bought too much that can’t be returned or you don’t have enough and then have to delay installation until the necessary component arrives. Furthermore, system suppliers often get better pricing since they buy in large quantities.

Support structures: If you need a stand-alone support stand for a specific item, such as a mixer or filter-receiver, then it often makes sense to buy it from the equipment supplier as part of the original purchase. They have already engineered and built the supports many times, so it will be fairly standard and inexpensive for them. On the other hand, if the support is very large, you can probably save money by purchasing it locally to avoid shipping costs. If your support structure is being designed by someone other than the equipment vendor, make sure you get the static and dynamic load information about the equipment and give that information to the engineer who will design the structure.

PBE

Part II of this article discusses the necessary project services that go along with building your system and guidelines for choosing a vendor.


For further reading

Find more information on this topic in articles listed under “System or equipment design, fabrication” in our article archive.


Todd Smith (316-350-5865) is the business and strategy manager for Kansas State University’s (K-State’s) Bulk Solids Innovation Center. The Center’s focus is to help industry with education, material testing, and project consulting for powder and bulk solids handling. He has spent more than 35 years in the bulk solids industry working in a variety of engineering and management positions. He has a mechanical engineering degree from KSU and an MBA from Kansas Wesleyan University.

K-State Bulk Solids Innovation Center • Salina, KS
785-404-4918 • https://bulk-solids.k-state.edu

Copyright CSC Publishing Inc.

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