What happens when system pressure exceeds the pre-charge pressure in an accumulator?

When system pressure exceeds the pre-charge pressure in an accumulator, the correct response is that the nitrogen gas compresses to allow fluid entry. This principle is based on how an accumulator functions. An accumulator typically consists of a gas chamber filled with nitrogen on one side of a diaphragm or piston and a liquid reservoir on the other side.

As the system pressure increases and surpasses the pre-charge pressure of the nitrogen gas, the gas compresses. This compression allows fluid from the system to enter the accumulator, which means that the accumulator can store excess hydraulic fluid, helping to smooth out pressure fluctuations within the hydraulic system and providing additional fluid when required.

The other selections do not accurately describe the behavior of an accumulator in this situation. For instance, the idea that the accumulator would release all fluid instantly conflicts with the controlled and gradual nature of fluid release in hydraulic systems. Likewise, describing the accumulator as working in reverse misrepresents its operational mechanics, as it doesn’t function in reverse when pressure thresholds are crossed. The notion that an accumulator becomes inoperable is also incorrect; rather, it continues to operate effectively by accommodating additional fluid while the gas compresses.