Description
Houghto-Safe NL1 from Quaker Houghton is a water Glycol fire resistant hydraulic fluid that has been designed to meet the demanding conditions seen in direct acting riser tensioner systems. This is largely due to its high levels of mixed hydrodynamic and boundary lubrication additives and has been validated in long-term OEM cylinder tests. Degradation of hydraulic fluid (evidenced by accelerated reduction in pH) has been observed in some DAT/N-Line systems.
Such degradation includes the formation of sticky, high viscosity, black residues that contain metal fines. Metal fines have been shown to react with organic acidic additives within water glycol fluids – under certain conditions, this can result in the observed black residues. These residues are of concern as they may deposit around sealing elements. It is also of concern that deposits might reach the interiors of anti-recoil valves and cause the system to fail.