The GRACO 557429 is a replacement rupture disk designed for use as a safety indicator in GRACO lubrication systems. It is typically made from a durable material (exact material not specified) and functions as a pressure relief device, rupturing at a predetermined pressure to indicate system overpressure or failure. It is intended for use with MJ, MSP, MHH, and MXP divider valves.

Key Features:

• Rupture Disk
• 3/8 in
• 8200 psi (some sources list 3250 psi or 565 bar; see note below)
• MJ, MSP, MHH, and MXP divider valves
• Color-coded for easy identification (Purple)
• Single-piece design for reliability
• Acts as a rupture-to-atmosphere indicator for system safety

Applications:
Used as a safety and diagnostic component in GRACO lubrication systems, particularly with divider valves, to indicate system overpressure or failure.

Installation Notes:

• Using genuine GRACO parts ensures compatibility, reliability, and maintains system safety standards.
• Ensure the system is depressurized before installation.
• Replace the rupture disk if it has ruptured or is damaged.
• Follow GRACO equipment manual for specific installation procedures.
• Regularly inspect the rupture disk as part of routine maintenance.