Pressure Relief/ Limiting Valve/ NG06-30 (FDBD)

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FDBD type valves are direct-operated pressure relief or pressure limiting valves used in hydraulic systems for limiting and/or controlling maximum system pressure. These valves are essential to prevent damages due to over pressurisation of the system. 

The valves use a spring loaded ball or poppet that prevents oil flow through it. When the system pressure exceeds the value set by the spring force, the ball/ poppet begins to lift off its seat thereby allowing some oil to flow through it. This pressure is termed as cracking pressure. Any decrease is the pressure again lowers the ball/ poppet into its seat preventing oil flow. 

When the valve opens, hydraulic fluid is allowed to flow from the high-pressure inlet (P) to the lower-pressure outlet (T). By releasing excess fluid, the valve maintains the system pressure at or below the set value. The greater the flow, more the ball/ poppet lifts, creating a larger path for the fluid and preventing further pressure increase. 

Refer below catalogue for additional details.