Plugs are used for a variety of purposes. They

Generally plastic plugs are used when durability and resistance to pressure are the primary consideration. In addition, plastic plugs also provide better safety while transporting or storing corrosive substances. They are also better able to hold their shape under adverse temperature conditions and can take greater amounts of damage due to bad handling and friction. They also protect from dirt and moisture. Plastic plugs may come in the threaded or non-threaded varieties. Threaded varieties provide better safety and coverage and may also prevent pilferage and contamination since they can be locked with a tear-off strip. Plastic plugs are very good for keeping out dust and other particles from entering. Additionally, plugs may also be of the flanged, raised surface, valve or pull types and these can be used for different applications like electrical connectors or to provide insulation. Some of the commonly available plastic plugs are: 1. Tapered 2. Push-fit 3. Threaded 4. Cylinder Valve 1. Tapered Plastic Plugs: Are used according to the dimension of the tube or pipe and are used to protect inner surfaces from dust, contaminants and humidity. 2. Push-fit Plastic Plugs: Can be used for a huge range of purposes like covering copper or aluminum tubing, as packaging tube plugs, connectors, etc. They also come with side or center tabs for additional security. They may be flexible or flanged and with an additional pull tab. Many of them have ergonomic designs to provide easier usage. These are generally made from softer plastic of different densities. 3. Threaded: These plugs provide great security while transporting or storing liquids and gases. Many of them also have a nylon gasket to give a better closure. It is important to check whether these plugs meet with UN and UNS specifications when transporting hazardous materials. Opting for an O-ring bead give additional protection against outside contamination and leakage. These plugs may be secured by hand or spanner. Some plugs also come with a slotted head so that they can be locked with a screwdriver. Those with a knurled head are easier to remove by hand. 4. Cylinder Valve: These plastic plugs play an essential role in safety while transporting gases like oxygen or propane and also liquefied nitrogen for domestic cooking. They are small and narrow in size and can be customized to meet individual requirements. The most important function is to protect the handlers who will be involved in the storage and transportation of gas cylinders and tanks. Many of these plastic plugs come with a safety label attached, so that the user can convey statutory warnings and emergency contact details. Plastic plugs have the advantage of providing a tight fitting seal especially if they are made to the correct specifications and dimensions. They are available at most hardware stores and with online retailers.