Five Key Issues to Pay Special Attention to When Purchasing an Air Compressor
1. Larger Compressor Equipment Is Not Necessarily Better
Compressor equipment is closely related to production, and the fundamental requirement is that it should be compatible with the enterprise’s own production process.Currently, there are various models and specifications of equipment on the market, and each type of equipment has its specific application scope and market share. Some excel in function realization, some in cost saving, some in efficiency improvement, some in technological advancement, and some in low failure rates.Some enterprises advocate "larger-scale equipment" during equipment updates and choose large-specification equipment to improve production efficiency. However, despite the larger equipment size, the expected efficiency is not achieved. The reason lies in ignoring that the scaling-up of equipment is a systematic project. For example, if bottlenecks in certain processes remain unsolved, simply focusing on scaling up a single type of equipment in isolation often leads to a situation where "a large horse pulls a small cart"—increasing comprehensive costs with little gain.The phenomenon of "a large horse pulling a small cart" is quite common in air compressors, caused by two factors:
During the selection stage, the air compressors chosen by engineers are often larger than the maximum demand of the driven load.
The load of air compressor applications is inherently variable, and the size of the selected air compressor must meet the maximum load. In reality, the maximum load only occurs intermittently, while the load is much smaller at other times.
The resulting consequences and manifestations are as follows: The air consumption of most factories is constantly changing. When consumption decreases, air pressure rises, and vice versa. This phenomenon, in turn, proves two things:
2. Advanced Technology Is Not Necessarily Suitable
Pursuing the advancement of compressor equipment technology is a common goal of equipment managers and manufacturers. However, while pursuing advancement, enterprise managers must first clarify the purpose of this pursuit and the problems to be solved.First, classify the functions of the compressor to determine which functions are essential, which are redundant, and which are auxiliary.It should also be recognized that when selecting a new technology, it is necessary to examine whether it has a good application track record in the same or similar fields, whether it is a mature technology, and whether it has application prospects.No matter how mature a new technology is in theory or how advanced its design methods are, problems are inevitable in industrial applications. When manufacturers later improve these problems, the enterprise’s equipment may face reduced versatility of parts (or even obsolescence) due to changes in relevant dimensions and parameters—resulting in huge waste and difficulties in future management.This risk must be objectively evaluated and taken seriously. Blindly adopting the "first to try" approach to select equipment and technologies that have not undergone industrial testing will lead to unfavorable consequences. For example, a domestic enterprise purchased a type of equipment two years ago—the only one of its kind in the country—and now still operates this equipment at a high cost.
3. Conduct a Comprehensive Assessment of Manufacturers
No equipment or manufacturer can achieve perfection in design and manufacturing. Choosing a type of equipment also means choosing a type of service.Therefore, before selecting equipment, it is necessary to understand the manufacturer’s technical R&D capabilities, operating mechanism, market strategy, manufacturing strength, and production and operation status as much as possible.Some manufacturers often promote equipment at low prices to seize the market, then make profits through high spare parts costs after users purchase the equipment. Some manufacturers tentatively enter certain fields with insufficient R&D capabilities and quickly withdraw from the industry if the industrial prospects are poor or they lose in competition. Some enterprises themselves face operational difficulties and poor financial conditions; if the situation worsens, they may face merger or bankruptcy.Choosing products from such enterprises will leave endless troubles for spare parts supply and after-sales service. It is necessary to gain an in-depth understanding of these enterprises’ business behaviors to find honest and potential partners.
4. Consider the Versatility of Technology and Spare Parts
When selecting equipment, it is advisable to require the versatility of equipment parts and their interchangeability with existing equipment as much as possible, and prioritize the use of standard parts.This not only facilitates the management and procurement of spare parts but also effectively prevents being restricted by the manufacturer’s exclusive production due to technical patents.Although some imported equipment are well-known brands, their domestic sales volume is small, so their service level often fails to meet expected standards. For example, many common parts such as bolts, nuts, bearings, and seals are mostly manufactured according to imperial standards, resulting in poor versatility. This means even small spare parts must rely on imports, leading to long procurement cycles and affecting production. To ensure production, enterprises have to increase inventory, tying up a large amount of capital.In fact, in the field of general compressors, domestic brands are not inferior to foreign brands in terms of product performance and quality, and have more advantages in after-sales service, purchase price, and maintenance costs. Therefore, there is no need for blind admiration of foreign products (the so-called "the moon is rounder abroad"). It is recommended that enterprises avoid purchasing equipment that is not produced locally in China as much as possible—this will definitely save enterprises a large amount of costs in subsequent operations.
5. Compatibility with Other Equipment and Processes
The use of equipment is not isolated. It is necessary to fully consider the compatibility of the equipment with the preceding and subsequent supporting equipment in the production process, as well as with production process parameters.In addition, constraints such as local natural resources, maintenance tools, maintenance capabilities, government policies, transportation conditions, and spare parts supply should also be taken into account.We can illustrate this with the market risks encountered when purchasing variable-frequency air compressors.After more than a decade of rapid development, screw air compressors have replaced piston air compressors and now face a highly competitive "red ocean" market. Power-frequency air compressors are ubiquitous, and price competition has left little profit margin for manufacturers. Therefore, some capable and proactive manufacturers have returned to their original focus, realizing that without innovation and R&D, there is no way forward.As a result, permanent magnet variable-frequency, two-stage compression, two-stage permanent magnet, and integrated air compressors have emerged like mushrooms after rain—many manufacturers seem to have seized a "lifeline." The "revolutionary" technology of permanent magnet variable frequency has become the focus of promotional efforts.However, can permanent magnet variable-frequency air compressors really adapt to all working conditions and air demand, and achieve perfect energy savings, as many salespersons claim?We need a balanced answer to provide theoretical support for users’ procurement. Indeed, the amount of energy saved depends on the working conditions of the air compressor and the parameter settings of the frequency converter, with the working conditions being the most important factor.The greater the fluctuation in the customer’s air demand, the better the energy-saving effect. A more direct indicator is the proportion of no-load time in the total working time.This view is reasonable, but it is well-known that no customer will choose an air compressor that deviates significantly from the actual working conditions. For example, it is almost impossible for a customer with an air consumption of 5 m³/min to choose an air compressor with a capacity of 10 m³/min.Salespersons promote this way based on the fact that when customers select air compressors, they rarely choose a model that perfectly matches the actual situation—they always leave a margin of about 10%.This aligns with practical situations, but as a user, you must have your own judgment and avoid falling into the trap set by salespersons.This requires compressor users to conduct multi-party research, comprehensive assessments, and overall evaluations of equipment quality and performance when purchasing equipment—rather than simply choosing the lowest-priced option.Therefore, different enterprises have different needs when selecting compressors. The best choice is the one that suits the enterprise itself; only equipment that the enterprise can effectively operate can exert its due efficiency.Equipment selection involves risks. Enterprises should establish an effective evaluation mechanism and procurement process to avoid various risks, select equipment that is efficient, energy-saving, cost-effective, and low in comprehensive cost—thereby enhancing competitiveness and laying a solid foundation for the enterprise’s development.
