HARDIDE CVD TUNGSTEN CARBIDE COATING EXTENDS LIFE OF ELASTOMERIC SEALS AND AND ENABLES HIGH TEMPERATURE SEAL DESIGN

摘要

Elastomeric seals in rotating or reciprocating equipment suffer from premature wear in abrasive applications and in some cases can limit the maximum operating temperatures of down-hole tools. The newly-developed Hardide CVD Tungsten Carbide coatings can help prolong seal life and increase equipment maximum operating temperatures. The coating protects the metal shafts or plungers from scratching and scoring that can result from rotation or reciprocation and which can accelerate elastomeric seal wear rate by an order of magnitude. Traditional thermal spray WC/Co coatings contain a Cobalt binder which leaches during operation exposing hard grains of Tungsten Carbide sometimes described as "cheese-graters" and which increase the wear of elastomeric seals. The Hardide CVD coating is free from Cobalt binder and as a result the coated metal counter-surface against which the seal operates retains a good finish in operation for longer and thus is less abrasive for the seal. Hardide coatings are also resistant to H2S and can protect metal components from aggressive corrosive attack in sour oil and gas environments.