A Pig Launcher is a designed and fabricated tool used to launch Pig’s inside Crude Oil, Petroleum Products or Gas Pipelines. Pig refers to pipeline intervention gadgets that are used to perform multiple maintenance operations such as cleaning and inspection inside the pipelines. Pig Launchers are generally funneled shaped Y sections that can be aligned with the main pipeline through which an operator can launch a Pig inside a mainline. These launchers can be pressurized or depressurized depending on the requirement of the pipe. Pigging in the maintenance of pipelines refers to the practice of using pipeline inspection gauges or ‘pigs’ to perform various operations on a pipeline without stopping the flow of the product in the pipeline. Pigs get their name from the squealing sound they make while traveling through a pipeline. These operations include but are not limited to cleaning and inspection of the pipeline. This is accomplished by inserting the pig into a Pig Launcher – a funnel shaped Y section in the pipeline. The launcher is then closed and the pressure of the product in the pipeline is used to push it along down the pipe until it reaches the receiving trap – the ‘pig catcher’.
If the pipeline contains butterfly valves, the pipeline cannot be pigged. Ball valves cause no problems because the inside diameter of the ball can be specified to the same as that of the pipe. Pigging has been used for many years to clean larger diameter pipelines in the oil industry. Today, however, the use of smaller diameter pigging systems is now increasing in many continuous and batch process plants as plant operators search for increased efficiencies. Pigging can be used for almost any section of the transfer process between, for example, blending, storage or filling systems. Pigging systems are already installed in industries handling products as diverse as lubricating oils, paints, chemicals, toiletries, and foodstuffs.
Pigs are used in lube oil or painting blending, they are used to clean the pipes to avoid cross-contamination, and to empty the pipes into the product tanks. Usually pigging is done at the beginning and at the end of each batch, but sometimes it is done amid a batch, e.g. when producing a premix that will be used as an intermediate component.
Pigs are also used in oil and gas pipelines: they are used to clean the pipes but also there are “smart pigs” used to measure things like pipe thickness along the pipeline. They usually do not interrupt production, though some product can be lost when the pig is extracted. They can also be used to separate different products in a multi-product pipeline. In simplest terms the PIG launchers and PIG receivers are the sections of the pipeline which allow the PIG to enter and exit the pipeline. They are generally funnel, Y-shaped sections of the pipe which can be pressurized or depressurized and then safely opened to insert or remove PIGs. Most pigging systems use bidirectional launchers and receivers that can work in either direction. This is important to allow the PIG to be retrieved by the launcher if there is a blockage in the pipeline which prevents it from reaching the receiver.
PIG launchers and receivers come with safety valves and locking system to prevent accidents. They are also optimized to be suitable to the pressure and temperature requirements of the pipeline. Launchers and receivers may be horizontal or vertical depending on the needs of the pipeline.
Some launchers are designed to hold multiple PIGs at once and configured to launch them according to preset conditions. This is extremely useful because it allows much of the work to be done remotely. Additionally, it prevents the launcher from having to be depressurized and repressurized again each time a single PIG is needed. It is the pressure from the flow of product that moves the PIGs through the pipeline. Thus, one of the main roles of launchers and receivers is to safely interface between the low-pressure outside world and the high-pressure pipeline. Contact Dannenbaum LLC for more information or for an RFQ.