Guidelines for Selecting Sealing Materials And Lubricants

Choosing appropriate sealing materials and lubricants is the key to ensuring stable operation and extending the service life of equipment.  Here are some specific selection suggestions:

1、 Choose the appropriate sealing material

①　Consider the work environment:

Whether the sealing working medium is liquid or gas, the compatibility between the material and the medium needs to be considered.  For example, liquid sealing should consider the compatibility between the liquid and the material to avoid causing the seal to expand or contract;  Gas seals need to consider the compatibility of materials with lubricants and greases.

The working temperature range of the sealing element requires the selection of materials that can adapt to these temperatures.  For example, rubber sealing materials perform well in temperature, humidity, and heat resistance, while plastic sealing materials such as polytetrafluoroethylene, polyethylene, polyurethane, etc. are more corrosion-resistant and wear-resistant, although their temperature range may be narrower.  Metal sealing materials such as stainless steel, copper, aluminum, etc. are suitable for high temperature and high pressure environments.

②　Considering work pressure:

The working pressure of the sealing system is an important factor to consider when selecting materials.  The pressure resistance of materials should meet the requirements of working pressure.  For example, for high-pressure environments, metal sealing materials may be more suitable.

③　Consider friction and wear:

Select materials with appropriate friction coefficient based on the speed of the seal's movement.

In order to achieve sufficient service life, the wear resistance of the material needs to be selected based on the movement speed and stroke.

④　Consider the structural type:

Different structural types result in different sealing principles (such as extrusion type, shaft lip type, or mechanical seal), which inevitably require different mechanical properties such as elasticity, strength, and deformation rate of the material.

⑤　Consider cost:

The cost of sealing materials is also an important factor in selection. Different materials have different costs and should be chosen according to actual needs.

2、 Choose the appropriate lubricant

①　Consider motion speed:

Low viscosity lubricating oil is selected for high-speed motion pairs to reduce frictional resistance;  Low speed motion pairs use lubricating oil with high viscosity to increase oil film thickness and improve lubrication effect.

②　Consider the load and load characteristics:

The larger the load carried by the friction pair, the higher the viscosity of the lubricating oil selected to provide better lubrication effect.  At the same time, lubricating oil with good oiliness and difficulty in squeezing out from the friction surfaces should be considered.

③　Consider working temperature:

For mechanical equipment under high temperature conditions, lubricating oil with high viscosity, high flash point, and good oxidation resistance should be selected;  Mechanical equipment operating under low temperature conditions should use lubricating oil with low viscosity, low pour point, and no moisture content.

④　Consider lubrication parts:

Choose the appropriate lubricating oil according to the different lubrication devices and parts.  For example, lubricating oil with high viscosity should be used for lubrication of vertical surfaces, guide rails, screws, and other parts to reduce loss.

⑤　Consider the composition and pH value:

For certain specific applications, such as human lubrication, water-soluble lubricants that do not contain substances that can irritate or cause allergic reactions to mucous membranes, such as products that do not contain alcohol, fragrances, artificial colors, or petroleum based ingredients, should be selected.  At the same time, choosing lubricants with a pH value similar to that of the human body can avoid interference with the environment.

⑥　Consider durability and texture:

Choose lubricants that can provide long-lasting lubrication to reduce the need for frequent reapplication.  At the same time, choose the appropriate texture according to personal preferences, such as thin or gel.

In summary, selecting suitable sealing materials and lubricants requires comprehensive consideration of multiple factors, including working environment, working pressure, friction and wear, structural type, cost and movement speed, load characteristics, working temperature, lubrication location, composition and pH value, durability and texture, etc.  By making reasonable choices, the stable operation and extended service life of the equipment can be ensured.