How to identify duo cone seals have been used?

When purchasing duo cone seals, how can one discern whether they are unused? What are the general differences between used and unused duo cone seals?Typically, used duo cone seals demonstrate signs of surface contamination and a worn appearance upon inspection. This contrasts with unused duo cone seals, which appear older overall.

Unused duo cone seals’ o rings are free from deformation, and there are no scratches on the surface and have a good resilience ability. Additionally, the resilience and overall hardness of the o ring of an unused seal remain unaffected by the operational environment. The most noticeable change in used duo cone seals is the progressive inward migration of the wear pattern on the metal seal ring surface, eventually forming a visible wear band with continued use. 

In the course of operation, the metal rings of duo cone seals experience wear due to friction, leading to potential minute notches on the edges of used metal seal rings, in contrast to the smooth, undamaged edges of new metal seal rings. Additionally, used duo cone seals’ metal rings may retain residues of oil stains or fine metal particles, a result of the amalgamation of friction-generated metal fragments with the oil, subsequently depositing on the metal seal ring's surface. Conversely, new duo cone seals’ metal rings are pristine and clean, exhibiting none of these traces.

Another distinguishing factor is the degree of aging in the o rings. Duo cone seals that have been in use, subjected to prolonged exposure to high temperatures or pressure environments, may show signs of hardening, cracking, or even breakage in their o rings. On the other hand, new duo cone seals’ o rings are supple and elastic, devoid of any apparent aging indicators. In practical identification, professional equipment can also be utilized to measure parameters such as the elasticity and compression set of the duo cone seals, differentiating new and old duo cone seals quantitatively, for instance, by conducting hardness tests on the o ring. The figure below displays the condition of the seal surface after use on the left, and the seal surface of an unused duo cone seal on the right.

Fuyote established in 1992, has been 30 years in china. Focus on floating seals design and manufacture. In the past two decades, large size floating seals are the main products in fuyote’s production line. Diameter from 300mm to 1105mm are the best-selling products in fuyote. In order to guarantee high quality of the products, Fuyote manufactures all components of mechanical face seals in house, from casting metal rings with high chromium molybdenum to manufacturing elastomer components.