For someone like Christyleigh who had too much pressure, you can get pressure regulators to lower the system pressure before any devices such as the hot water tank. In this case I would put the accumulator tank (thanks JohnRPollard) after the
pump but before the pressure regulator maintaining a reserve of higher pressure water. These are passive spring loaded devices.
I thought I would mention it because it could save somebody else from buying a new
pump. I paid about $30 for one at a supply house not too long ago.