What is O-ring and packing?

In this article, the topic of O-ring and packing is discussed. O-ring is very easy to install, which makes it always in demand in the market. O-ring is the most common and convenient type of seal used for felt bowls, moving parts and seals on shafts and other parts. The felt bowl is also used in all parts where it is necessary to prevent the spread of oil or liquids.

Rotary seals that are used only for sealing the piston and shaft of pumps are called packing. would take Early steam engines were started with this type. The progress of crude oil production and extraction in the 19th century improved the materials used in packing. In the 19th century, packing was considered one of the most used seals because of its simple architecture, affordable price, and favorable accessibility.

In parts of the pump, there is leakage or air entering the pump, so by choosing a high-quality sealing system, you can protect the fluid and prevent air from entering the pump. Various raw materials are used in the production of packings, such as; Plastic, natural rubber and synthetic rubber. Packing will work by creating fluid pressure that causes the edge of the seal to stick to the wall and make it work better. The consumption of packings is about one pack, of course, you can put several seals together in one groove.

Packing sealing consists of different parts:

< b>- felt bowl
- lining
- sealing cap

Packing works in one-sided and two-sided form, which can withstand pressure of 250 to 700 bar. The position of the packings is determined according to the outer and inner edges of the packing. If the outer edges are longer, they are placed in the throat part, and if the inner edges are longer, they are placed in the piston part.

If both the inner and outer edges are symmetrical, use the appropriate piston and throat will be Some packings are used in rows and others in multiple pieces. In the meantime, layered packing is an example of a ring made of natural rubber. In some cases, a support ring is used next to the packings to increase tolerance.

All industrial parts that are somehow connected with gases and fluids need good sealing to prevent material from escaping. Various methods are used for sealing, among which welding, soldering and good machining can be mentioned. Another method is done by using flexible and soft material. These materials are trapped between two strong and hard materials and perform the sealing work. Plastic o-rings should be considered as an incompressible fluid with a high viscosity that has a suitable surface tension. If a regular pressure is mechanically applied to the O-ring through the construction of the environment or through hydraulic fluid, this viscous substance will flow inside the gland and prevent fluid penetration. This process causes complete sealing.

Due to the pressure, the rubber material is likely to take a certain appearance or find a memory state in some way and cause the joints to seal. Note that after proper installation, the O-ring is mechanically pressed into place to prevent fluid from passing through. If this material is under pressure, it will go out of shape and penetrate into the grooves of the gland to make a better seal.

According to the application of packing, they are produced and presented in different sizes and raw materials and different materials. so that the required efficiency in front of environmental factors such as; have pressure, heat, and wear and corrosion. Packings are usually made of natural and synthetic rubber, plastic or different raw materials such as VITON, EPDM, Silicon, PTFE, PU, ​​FKM, etc.). For example, its NBR sample is used in normal rubber packing jacks. In general, due to the practicality of this device, many centers offer them, which include backup rings and O-rings.