Flow lines are pipe lines that are constructed to direct the flow of some type of liquid or gas from a source to either equipment used to process the substance or to some type of storage facility. It is not unusual for a flow line to be equipped with electronic monitoring devices and other features that make it possible to control the rate of that flow during the transfer. Depending on the exact function of the pipe flow line, various safety regulations may apply to the construction and ongoing operation of the system.
A common example of a flow line is used in the collection and processing of oil. While system designs for the line may vary somewhat, a basic line on a drilling rig will require the use of piping that has a larger diameter. At one end, the pipe is connected to what is known as a bell nipple just under the drill floor. It is at this point that the oil enters the pipeline. At the opposite end, the line is connected to what is known as a possum belly. The belly, which is simply a wider section that serves as a return line, then routes the product to tanks that filter impurities from the oil and store the collected product.
A similar process is used with a water flow line. Many municipal water systems utilize the line to route water that is extracted from sewage systems and route the contaminated water to purification facilities. Some systems utilize a series of filters that help to remove some of the larger contaminants for processing in a different area of the plant. The pipe flow line moves the water through the plant, where it emerges and can be returned to the municipal water system or allowed to flow into a body of water such as a stream, river, or lake. Since the water has been decontaminated, it poses no threat to any marine life in the body of water.
The construction of a flow line normally involves the need to comply with any governmental safety and structural regulations that are in force in the area where the line is located. Doing so helps to ensure that the potential for the system to fail and the opportunity for contamination or danger to lives and the surrounding environment is kept to a minimum. Periodic inspections of each section of the line help to make sure the system remains in compliance with those rules and regulations.