What to Consider for Oil-less Air Compressor Maintenance?

In the previous post, we outlined some of the considerations for selecting either a reciprocating or rotary scroll air compressor. One of the major considerations will be the routine maintenance, which in turn will affect the “Cost of Ownership over a specified period of time”.

Maintaining Oil-less Air Compressors, Reciprocating and Rotary Scroll

Both reciprocating and oil-less air compressors require very little maintenance. The following items are basic requirements for either type of compressor.

  1. Air Intake Filter: It is a basic concept that in order to compress air, you must be able to intake air to the compression chamber. Air intake filters protect the compressor from ingesting contaminants that may cause cylinder and piston ring wear or damage, or cause intake and discharge valves to malfunction. As the filter becomes restricted by contaminants, the compressor will lose capacity. Depending on the cleanliness of the location, and the amount
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Oil-less Air Compressors- The Evolution in Air Compression

Early Designs

There are several types of oil-less air compressors available on the market, and the selection of aOIL-LESS-COMPRESSORS compressor will usually be determined by the application’s volume and pressure requirements, and in some cases, how and where the air will be used. The industry has changed over the past 50 years, and going back to times prior to the 1970’s, most oil-less air applications for standard pressure (up to 125 PSIG) were serviced by reciprocating air compressors. For large industrial applications, these compressors were available in the single stage (for pressures to approximately 100 PSIG) and 2-stage machines (pressures above 100 PSIG). For high volume applications, these machines were usually massive, with cast iron frames, and were water cooled by way of cooling jackets in the compression cylinders and heads. Most of these machines were double-acting (compressed air on both the upstroke and down-stroke of the piston) using a … Read the rest


Some Considerations for Designing an Air Burst System

Air Burst System

Air burst systems are a standard requirement for municipalities and industries that draw water from rivers, lakes or ponds. The air burst system is designed to keep intake screens below the water level clear of debris and silt which accumulate as a result of inward water flow. The basic principle is to displace these materials with a high volume blast of compressed air in reverse flow direction through the screens. The systems are normally designed to be automatic and operate on a timed basis, calling for an air burst usually once or twice a day, or as required/established, depending upon the intake water conditions. Some basic calculations must be made to determine the volume of air required (relative to the screen size), air storage receiver size, and piping and air burst valve size based on air volume and distance from valve to screen. A good control design will allow the … Read the rest


Purge Economizer Controls

Purge Economizer Controls Air Power Products Limited has been supplying our “Purge Economizer Control$” systems for over 25 years. The original intent was to supply our customers with a system that not only save compressed air, but would also indicate what those savings amount to. The second initiative was to provide these features at a reasonable cost that would provide a quick ROI for the user. That was 25 years ago! Today the issues of saving compressed air is of even greater importance as the cost of electrical services rise. Not only are these issues recognized by compressed air users, but they are also recognized by the utilities that provide the electrical services. Our price for this control system over the past 25 years has remained very consistent and price competitive.

We have recently added some user beneficial options which, although they increase the cost of the control system, can be easily offset … Read the rest


Changing Compressor Oil

Lubricated reciprocating air compressors, like an automobile, require regular oil changes to ensure that bearings and piston skirts are receiving clean lubricant to prevent metal to metal contact. Most small reciprocating compressor manufacturers recommend oil changes every 12 months or 500 hours – whichever comes first. Many small reciprocating air compressors may operate on single phase power directly fed by a breaker. Three phase models may use an economically priced off-the-shelf magnetic motor starter. In both of these scenarios, there is usually no provision made to log hours on the compressor.

The Problem with Start/Stop Air Compressors
The problem with compressors operating on a start/stop basis, is that the user usually has no idea of the actual hours that accumulate on the air compressor. As a result, oil changes are often neglected, or allowed to run past the due date. This may result in excessive wear causing reduced life … Read the rest


Desiccant Air Dryer Types, Application Considerations and Solutions

AP-100-FP-A-compressorAlthough heatless dryers are simple in design, very reliable, and generally a low maintenance machine, the high cost to produce purge air for their use is a drawback to their use. Purge consumption may actually represent a higher percentage of actual air demand, as heatless dryers on a fixed time cycle will continue to use the same volume of purge air regardless of system demand. This excess purging will result in lower dew points which are usually not a requirement. As the dryers are normally over-sized to account for peak demand, and that demand may be reduced substantially throughout the production cycle, it is beneficial to invest in the option of “Purge Economizer Control” which will maintain a constant dew point control (within 2-4ºF), and will reduce purge flow through the monitoring of the outlet dew point. Purge consumption can be reduced substantially using this optional control system,

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When Will A Refrigerant Dryer Not Provide Suitable Drying?

In some applications, compressed air lines may be exposed to temperature below freezing levels. In these applications, the pressure dew point must be reduced to below the levels that a refrigerant air dryer can achieve, in order to prevent ice from forming in the compressed air lines. There are many applications where compressed air may come into contact with chemicals, food products or other products in which water vapor in the compressed air may interact negatively in the process. These applications are referred to as “process” applications, and it is often necessary to remove almost all of the water vapor from the compressed air. There are also applications where compressed air is used for instrumentation purposes, and water vapor will negatively affect the instruments.

These are all applications where desiccant air dryers are required. There are international standards for purity of compressed air for particulate and oil content, and dew

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When Should A Refrigerant Dryer Be Used?

Refrigerant Dryer

There are several types of compressed air dryers on the market, and many different applications for drying compressed air. Many industrial and commercial applications for compressed air will be for hand tools or the operation of pneumatic cylinders and valves in an indoor applications. These are referred to as “power” applications. For the most part, these applications require the air to be free of condensate (free liquid), which will impede the tool’s performance and cause corrosion, shortening the life of the tool. Refrigerant air dryers are usually selected for these applications. They remove water vapor from the compressed air by means of cooling the incoming air to a level within the design dew point range, separating the condensate, and then draining it off.

Dew Point Requirement in Power Applications

In most refrigerant dryers (usually 15 CFM capacity and larger), the compressed air is re-heated after the separation stage, providing a

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Why do I Have Water in My Compressed Air Line?

When air is compressed to approximately 1/7 of it atmospheric volume (for 100 PSIG applications), there is a rise in temperature during the compression phase. This temperature rise allows water vapor in the air to be held in suspension during the compression stage. As a general rule of thumb, air will hold almost double the amount of water vapor in suspension with every 20ºF in temperature rise. This temperature rise is normally anywhere from 170 to 400ºF (76 – 205ºC) depending upon the type of air compressor being used. After compression, the air will cool as it travels through piping, air receivers, and other devices. As the air cools, at some temperature level, (dependent upon the relative humidity of the air at the compressor intake), it will reach its saturation level (100% RH), and further temperature reduction past that point will result in condensate forming in the air line. Most … Read the rest