When the spring tension in the pressure relief valve is decreased, maximum pressure in the

system pressure decreases

Explanation:

A relief valve is a device designed to reduce the pressure of a system when it exceeds a maximum pressure established above, it works with a spring that presses a seal when the pressure exceeds the set value the spring deforms, allowing fluid to escape into the atmosphere and decreasing internal pressure.

Considering the above when the spring tension decreases, it means that the system pressure decreases

maximum pressure in the system decrease

Explanation:

A spring loaded PSV (pressure safety valve) is a traditional pressure control valve which is designed to work at a predefined pressure and also to safeguard a vessel or framework from large amount of  pressure by eliminating or draining fluid from such a system.

The resultant stress on disc is reduced once the inlet pressure is less than the defined pressure and the disc stays positioned in locked position on nozzle. As stress of the system rises to the given amount, the resulting force slowly reduces to zero.