Precision Air Bleed Orifices for Hydraulic Systems

Remove trapped air from you hydraulic system while mimimising system losses with The Lee Company range of precision orifices.

The Lee Company introduces our newest solution for removing trapped air within a hydraulic system with our 5.5mm Air Bleed Orifice. Trapped air in hydraulic systems can cause issues with performance as air is compressible, whereas hydraulic fluid is not. Trapped air causes slower system reaction times or a “spongy feel”. The traditional way to remove trapped air from a hydraulic system has been to drill a hole, approximately Ø0.5mm, in the manifold allowing this air to escape back to the sump, eliminating its effect on system performance. This drilled hole also allows hydraulic fluid to flow out of the system, resulting in significant hydraulic loss, inefficient system performance, and wasted energy. In today’s environment, technology is pushing for higher system efficiencies, reduced weight and size, and increases in system pressures, which only makes reducing these system losses more critical.


Our new Air Bleed Orifice is a novel solution to removing trapped air while keeping hydraulic losses to a minimum. Utilizing a small precision flow orifice, this new Air Bleed Orifice allows trapped air to escape but is small enough to restrict most hydraulic flow, minimizing system losses. The Air Bleed Orifice also features an integrated safety screen for contamination protection. Using Lee’s Air Bleed Orifice enables system designers to optimize system component sizing, leading to improved efficiencies, reduced weight, and lower costs.


• Small Precision Orifice - Removes Trapped Air While Minimizing System Losses

• Self-Retained Design
• Rated to 21 MPa
• 100% Flow Tested
• Integral Safety Screen


• Removes Trapped Air in Hydraulic Systems
• Automotive, Off-Road, and Industrial Hydraulic Systems

Get 3+ quotes so you can compare and choose the supplier that's right for you