空压机选择的基本准则有三条，可靠性、安全性与经济性。 一、机器的使用环境和条件。在场地无供水，场地狭小的情况下，选择立式空压机;场地有长距离的变动(超过500米)，须考虑移动式空压机;场地不能供电，则必须选择风冷式。客户们经常错误的认为水冷式比较好，其实在国内外小型空压机中风冷式占百分之九十以上。原因是风冷式空压机在设计上更加简洁，无需水源。水冷式空压机必须具备完善的供水系统，投资大;水冷却器寿命较短;运行过程中大量浪费水资源;北方冬季易冻坏气缸。 二、所需压缩空气的质量。一般的空压机都含有一定的润滑油，且含有水分，在禁油禁水的场合不仅要注意空压机的选型，在必要的时候还要增加附属装置。此时可选择无油空压机。无油空压机基本不含油，但润滑不良，因此故障率高;此种空压机因含有聚四氟乙烯，食品及制药行业不能使用，无油空压机只能做到不含油，但无法做到不含水。也可在空压机后添加净化装置或干燥机，这种装置能够使空压机不含油和水分，使含油水量在5ppm以下。 三、空压机的排气压力及排气量。常用的空压机排气压力为0.7MPA，0.8MPA，目前社会上还有排气压力为0.5MPA的空压机，输气距离过近。这种空压机为一级压缩，压力比太大，易排气温度过高，造成气缸积炭，导致事故的发生。大于0.8MPA的空压机一般要特别制造，不可强行增压。空压机气量的选择要匹配所需的排气量(并留有百分之十的余量)，
There are three basic criteria for selecting an air compressor: reliability, safety, and economy. 1、 The operating environment and conditions of the machine. When there is no water supply on the site and the site is narrow, choose a vertical air compressor; Long distance changes to the site (exceeding 500 meters) require consideration of mobile air compressors; If the site cannot be powered, it must be air-cooled. Customers often mistakenly believe that water cooling is better, but in fact, wind cooling accounts for more than 90% of small air compressors both domestically and internationally. The reason is that air-cooled air compressors are designed more simply and do not require water sources. The water-cooled air compressor must have a complete water supply system and a large investment; The lifespan of the water cooler is relatively short; A large amount of water resources are wasted during operation; The cylinders in northern winter are prone to freezing and damage. 2、 The quality of compressed air required. Generally, air compressors contain a certain amount of lubricating oil and moisture. In situations where oil and water are prohibited, it is not only important to pay attention to the selection of air compressors, but also to add auxiliary devices when necessary. At this point, an oil-free air compressor can be selected. Oil free air compressors generally do not contain oil, but their lubrication is poor, resulting in a high failure rate; This type of air compressor cannot be used in the food and pharmaceutical industry due to the presence of polytetrafluoroethylene. Oil free air compressors can only be oil-free, but cannot be water free. Purification devices or dryers can also be added after the air compressor, which can make the air compressor free of oil and water, and keep the oil and water content below 5ppm. 3、 The exhaust pressure and volume of the air compressor. The commonly used air compressors have exhaust pressures of 0.7MPA and 0.8MPA. Currently, there are also air compressors with exhaust pressures of 0.5MPA in society, and the gas transmission distance is too close. This type of air compressor is a first stage compression, and if the pressure ratio is too high, it is prone to high exhaust temperature, causing carbon deposits in the cylinder and leading to accidents. Air compressors larger than 0.8MPA generally need to be specially manufactured and cannot be forcibly pressurized. The selection of air compressor volume should match the required exhaust volume (with a 10% margin),
