Why is It Tough for Hydraulic Oils?

• Hydraulic oil systems are getting smaller
• High oil flow rates relative to oil quantity
• More power is expected from pumps
• Hydraulic oil temperatures can be extreme
• Hydraulic oil is expected to last longer
• Higher temperatures result in varnish

Why is varnish bad?

• Servo valves stick due to varnish, resulting in downtime and lost production
• Increase in wear as varnish attracts contaminants and wear particles
• Restricted oil flow when varnish clogs filters and strainers
• Higher operating temperatures because varnish forms an insulating film
• Increase in maintenance costs due to resources needed to clean system components

Developing a solution

Lubrizol conducted extended Eaton Vickers 35VQ-25 pump tests. These tests were run under normal conditions except the test duration was extended to 1000 hours. Time after time traditional fluid technology showed the formation of varnish in the system reservoir and hydraulic components after only 500 hours of use.

A new way to prevent varnish buildup

Lubrizol® 6776 is designed to meet all of the traditional hydraulic oil requirements but also add a new benefit: It keeps hydraulic systems clean. A formulation containing 1.4 wt.% Lubrizol 6776 in Group I base oils was tested in an extended Eaton Vickers 35VQ-25 pump test that was allowed to run for 1000 hours. The result was a clean reservoir and clean system components.

 Case Study on Potential Cost Savings

• Large plastic injection molding company
• Operates 24 hours/day for 5 days per week
• Replaces or cleans 60 servo valves per year
• Total cost to customer for valves and labor is $130K/year not including downtime

Benefits of Lubrizol 6776

• Excellent oxidation life, helping to extend life of oil and prevent varnish formation
• High level of thermal stability, which helps minimize the formation of varnish
• Excellent demulsibility, so water separates quickly
• Outstanding antiwear system to protect system components,
• High level of rust and corrosion protection, extending,component life
• Excellent filterability