Regarding the piston ring issues in reciprocating compressors

Your question is quite complex... Piston rings and support rings are made from different materials depending on the grade, operating conditions, and other factors. Filled polytetrafluoroethylene, filled polytetrafluoroethylene (with copper powder), and the type of piston ring to use is determined depending on whether there is an oil injection point or not... There is a lot of information available online about reciprocating compressors, and plenty of it can be found on Baidu – just search for it

1. Filled PTFE (filled polytetrafluoroethylene) HY546 has high hardness and a low coefficient of friction; it is suitable for medium-pressure (40–100 bar) applications with oil present. HY520 has good thermal conductivity and is often used in high-temperature, high-speed oil-free air compressors and oxygen compressors. HY501 has high load-bearing capacity and good wear resistance; it is suitable for low-pressure, oil-containing operating conditions (100 bar). HY511 features high strength, a low friction coefficient, and good temperature resistance, making it appropriate for high-pressure, oil-containing operating conditions. Phenolic resin HY547 is suitable for harsh operating conditions such as those without oil, with chrome plating, or at high pressures up to 150 bar. The above are 4 common non-metallic materials and their properties; the piston rings in my previous workplace were made of PEEK.

There are too many materials available, and different options exist depending on the manufacturing process. You can provide details about your application conditions, and we’ll help you choose the right one

This post was last edited by 3051Hart on 2016-11-9 at 21:21. There are two common materials used for piston rings: The first is RPTFE, which is filled modified polytetrafluoroethylene; it is the most widely used material. Manufacturers typically offer various formulations to suit conditions involving low, medium, or high pressures, as well as scenarios with little or no oil present. The second type is PEEK (polyether ether ketone), which is mainly used in applications with particularly high pressures (>150 bar); in such cases, a small amount of oil injection is usually required. Many manufacturers refer to RPTFE as 4F (polytetrafluoroethylene) material; since polytetrafluoroethylene was the first material to be introduced, it has become customary in many places to use the term 4F to refer to both polytetrafluoroethylene and its filled, modified versions. RPTFE wears out very quickly under high-pressure conditions, so it is not recommended for use in such scenarios. PEEK has a lower self-lubricating property than RPTFE, but it can withstand high pressures. RPTFE has better elasticity than PEEK, so usually only one piece is cut out from the entire circumference, resulting in just one cut. Due to its poor elasticity, PEEK cannot be made in the same way as RPTFE; it is usually divided into two halves, with some versions having a steel elastic ring inserted inside. There are also those without it.