DiamondFace – Innovative coating technology ensures maximum operational reliability for compressor seals

Innovative coating technology ensures maximum operational reliability

EagleBurgmann’s innovative DiamondFace coating as used on liquid-lubricated seals has an excellent track record even under extreme conditions, and more than 2,000 mechanical seals with this technology have since been installed worldwide. This DiamondFace technology has now been enhanced for use on the broad silicon carbide seal faces on compressor seals. In doing so, EagleBurgmann is offering an unprecedented plus in terms of operational reliability and performance under all compressor operating conditions in which the sliding faces of DGS seals might come into contact with each other. Compressors are used in the spheres of oil and gas production, gas transportation and storage, air separation systems, the petrochemical, refinery and chemical industries and many other sectors.    

Practical experience has shown that difficult operating states – such as *turning, ratcheting and frequent coast-down intervals in which the compressor runs for hours, days or even months at a time at speeds below the seal face lift-off threshold or beyond the operating limits of today’s gas seal technology – are not at all uncommon. Because the sliding faces on DGS seals are designed primarily for non-contact operation, contact for sustained periods can make them subject to wear. This can ultimately damage the sealing faces, causing seal failure which in turn leads to compressor downtime.  

The plus in terms of operational reliability and performance is now achieved by depositing a fully continuous layer of crystalline diamond with a precisely defined thickness on the structured mating surfaces of gas seals. During operation, the coating provides effective protection for the seal faces against wear and damage. The chemical bond between the diamond and the silicon carbide creates an extremely rugged coating which does not impair the lift-off capabilities of the seal faces. This significantly reduces the risk that compressor seals will be damaged or fail during turning, ratcheting, frequent coast-down intervals or under sub-optimal compressor operating conditions.  

* Turning refers to when the compressor runs very slowly at low rpm (approx. 0.2 … 1 min-1), e.g. in standby mode. In this case, the seal faces – which are normally designed to cater for turning mode for a specified time only – are in constant contact. Longer periods of operation in this mode make for added wear and ultimately lead to damage to the seal faces. Ratcheting: The shaft is rotated 90° at regular intervals to prevent deformation caused by thermal effects. There is full contact between the seal faces, which are likewise subject to corresponding wear over time. Coast-down describes the situation in which the compressor coasts slowly down for a long time under controlled conditions before it comes to a stop. When the speed decreases to the point at which the sliding faces no longer lift off, there is then constant contact between the seal faces, leading to wear and damage of the sealing rings.

Advantages of this innovative coating technology:

  • Extreme hardness and unsurpassed protection against wear 
  • Excellent thermal conductivity 
  • Optimal chemical resistance
  • Service life increased many times over
  • Intervals between maintenance calls increased to at least 10 years
  • Significantly reduced lifecycle costs