Oleodinamica Marchesini V0638/9 VU MM 1 1/2 male/male in-line check valve — 9 bar cracking pressure

Oleodinamica Marchesini V0638/9 is the VU MM 1 1/2 male/male in-line check valve with the explicitly listed 9 bar cracking-pressure spring and 1 1/2" BSP connections. The complete calibrated article code is printed in the factory spring matrix and selected on the named-brand supplier offer. The size row gives 320 bar maximum operating pressure.

Connect V to the pressure supply and C to the downstream circuit. The spring-loaded guided poppet permits flow from V to C and blocks reverse flow from C to V. Cracking pressure is an opening differential; it is separate from the maximum pressure rating and from pressure loss at operating flow.

The factory size row specifies maximum flow of 300 l/min.

The body is zinc-plated steel with hardened and ground internal parts. The factory describes guided-poppet sealing without leakage but does not identify a seal compound. The common body drawing gives length L of 86 mm and hexagon size 55 mm. The wildcard size row lists mass 0.910 kg; this remains a common-body reference rather than an independently weighed spring option. The exact 9 bar spring is identified by the full code rather than inferred from the standard 1 bar row.

The local technical PDF includes the complete relevant original manufacturer spread with the applicable article row, spring matrix or stainless example, hydraulic diagram and installation drawing. Neighbouring rows apply only to their stated executions. Oil temperature 50 °C and viscosity 30 cSt beside the curves are test conditions, not operating temperature limits.