CPI offers a variety of packing and wiper rings to satisfy operator's requirements in selected materials specific to their application. Packing rings are the elements which make the seal, compensate for wear, movement of the rod, and temperature change. There have been many patents obtained on various types of packing rings; however, the most popular and widely used design is that patented by A. W. France, November 7, 1899.


Packing Rings

CPI combines a wide range of metallic and non-metallic materials and a variety of designs to meet with many typical packing requirements and also the more specific and problematic ones.

The range of materials that CPI utilizes are available across the broad range of packing rings designed for unidirectional and bidirectional sealing, low pressure vent and gas purge sealing. This also includes high-speed and high pressure rings, as well as sandwich and triple circle designs.

Wiper Rings

CPI oil wiper rings are designed to effectively provide positive containment of lubricants within the crankcase. The CPI scraper is designed specifically for those applications where total oil control is necessary. Most reciprocating compressors use oil control or wiper rings to prevent crankcase oil from passing into the cylinder and in some instances to prevent condensate and cylinder and packing lubricant from entering the crankcase. 

Segmented wiper rings may be either radially or tangentially cut. They are garter spring actuated. The scraper edges in contact with the piston rod are proportioned to give a bearing load sufficient to break the surface tension of the oil film on the rod and wipe it away. While there are many variations and innovations of wipers, there are basically two types. Normally two or three wipers are used in an oil seal and as previously indicated may be used as a part of or in conjunction with a pressure packing.

The CPI scraper is designed specifically for those applications where total oil control is necessary. Available in both cast iron and bronze, the unique design and operation of these rings provide extremely effective containment of lubricants in their intended area as well as long trouble free service.

The unique design and operation of these rings provides extremely effective containment of lubricants and long trouble-free service.

Basic Packing Ring Designs:

  • Single acting seal rings/pairs
  • Double acting seal rings/pairs
  • Backup rings
  • Pressure breakers
  • Pressure breaker with relief slots

Basic Wiper Ring Designs:

  • tangent cut unidirectional
  • tangent cut bidirectional
  • radial cut wiper rings 

Packing and Wiper Ring Materials:

  • CPI Special Polymer Alloys
  • PTFE
  • Thermoplastics
  • Bronze
  • Cast iron

Liard Wiper

CPI Liard Wiper Ring