Eaton TB155S4-4 - Aeroquip 145/155 Bulkhead Half -4

The Eaton TB155S4-4 is an Aeroquip 145/155 Series Bulkhead Half (Style I) in AN size -4 (1/4"), engineered for panel and bulkhead mounting in aerospace hydraulic systems. Unlike hose halves, this fitting is fixed to a structural panel, aircraft skin, or hydraulic manifold, providing the stationary connection point that the hose half plugs into during ground servicing. Rated to 3000 PSI with Nitrile seals provide reliable compatibility with petroleum-based hydraulic media.

Bulkhead Mounting Design Features

• Designed for rigid panel installation — bolts or clamps through the bulkhead mount point
• Style I configuration mates with a hose half on the operator side only
• Automatic self-sealing valve prevents fluid loss when the hose half is disconnected
• The compact 1/4-inch bore delivers precise, low-volume flow control for servo actuator circuits

Constructed from aluminum alloy, the TB155S4-4 withstands vibration, pressure cycling, and temperature extremes encountered in ground service environments. The blunt-start quick-lead threaded ratchet lock — rotated by hand and secured by ratchet teeth engaging a lock spring assembly for vibration-resistant positive engagement provides positive locking without tools. Certified to MIL-C-5502, MIL-DTL-25427B, and SAE AS5440 Type II, this bulkhead half meets all requirements for military aircraft ground service operations. It is compatible with MIL-H-5606 (red) and MIL-H-83282 (fire-resistant) hydraulic fluids.

Typical Installations

• Aircraft hydraulic system ground service ports
• Ground support equipment (GSE) bulkhead panels
• Hydraulic test stand manifold mounting points
• Military aircraft MRO facility service panels (servo actuator circuits, instrument hydraulic lines, and brake accumulator systems)