The Use Of Wavy Face Technology In Various Gas Seal Applications

Abstract

Wavy face technology in mechanical face seals is the use of circumferential waves manufactured into a seal face. This unique wavy shape is bidirectional, can be used in liquids, gases or combination, and incorporates a sealing damn that minimizes leakage. The combination of waviness, tilt at the valleys of the waves, and a seal dam has been referred to as the wavy-tilt-damn or WTD. The WTD shape provides both hydrostatic and hydrodynamic load support that is sufficient to enable the seal to operate in a noncontracting mode during dynamic operation. The smooth wave peaks present a low wearing condition during start and stops when the seal faces make contact. Field results also indicate that the WTD shape is contamination resistant and exhibits lower leakage than grooved face technology. Since its introduction in dry running noncontacting gas backup seals, wavy face technology has been applied to many different applications and seal design configurations. More than 2000 wavy face seals have provided successful performance since 1995. Other applications of this technology include its use as primary seals in liquid carbon dioxide, double gas seals in ANSI and API pumps, tandem seals in high vapor pressure NGl services, and compressor seals for high speed/high pressure conditions. Wavy face technology has been successfully applied in field applications from zero to over 1100 psig and up to 34,000 rpm. Laboratory testing has been successful up to 1350 psig. This paper will discuss some of these applications and report on performance from field installations.