Original Equipment Manufacturer (OEM) are the companies that produce the baghouses in which process off gases are collected. Environmental baghouses collect these gases, which contain solid pollutants such as fly ash from burning coal to fire a boiler. Process baghouses collect these gases, which contain solid that are 'product'. This product could be cement or aspirin ect. This type of baghouse is called Product Recovery.
The original bags installed in a new baghouse are usually called first fit filter bags. All subsequent bags are called replacement filter bags.