Which accumulator type is less bulky and does not discharge at constant pressure?

• A. Spring-loaded accumulator
• B. Weight-loaded accumulator
• C. Gas-charged accumulator
• D. Diaphragm accumulator

Answer: (A)

When energy is stored in an accumulator, the way the opposing force changes as the fluid is discharged determines how the pressure behaves. A spring-loaded accumulator uses a spring to push against the piston. As the hydraulic fluid leaves, the piston moves and the spring compresses more, so the force—and thus the pressure—in the system increases during discharge rather than staying the same. This causes the pressure to vary rather than be constant, which is the behavior described in the question. Spring-loaded designs are also typically more compact than other types, because they don’t require large gas chambers or heavy weights. In contrast, weight-loaded accumulators provide a nearly constant pressure because the weight is fixed, and gas-charged or diaphragm/bladder types rely on gas compression or flexible membranes that usually require bulkier chambers to maintain a stable pressure. So, a spring-loaded accumulator best fits both criteria: it is relatively less bulky and it does not discharge at constant pressure.