backup ring

This Backup Ring is made of phenolic plastics. Phenolic plastics is mainly composed of phenolic aldehyde resin and clothes strips, besides adding some additional material according to the different application requirements. The phenolic plastic is made to specific shape by hot forming under pressure.  Different kinds of the phenolic plastics are made in different forming conditions.
The finished Backup Ring have good insulation, physical and mechanical features. Afterwards the back-up ring will be lined with rubber material to form a resilient valve seat. It gives enough support of the resilient valve seat and guarantees the long-lasting use.
Furthermore, the Phenolic Backup Ring is cheaper than Aluminum and Cast Iron Backup Ring, it reduced the cost of the resilient valve.

This Backup Ring is made of Cast Aluminum, and machined with high precision machining equipment. It has good physical and mechanical features. Afterwards the back-up ring will be lined with rubber material to form a resilient valve seat. It gives enough support of the resilient valve seat and guarantees the long-lasting use. 
Furthermore, the Aluminum Backup Ring pays well in economy for larger size resilient valve.