Camco makes a flex hose kit and an accumulator tank that could be added to the system to help reduce noise. Search Amazon for them...
A lot of the noise could be piping banging on floor or cabinet sides, and the pump being screwed down on the floor. Isolation mounts for the pump and come rubber-lined clips to keep piping from vibrating can also help.
Rich, KE4GNK/AE, Overkill Engineering Dept.
'The Silver HamShack' ('07 International 22FB CCD 75th Anniversary)
Multiple Yaesu Ham Radios inside and many antennae sprouting from roof, ProPride hitch, Prodigy P2 controller.
2012 shortbed CrewMax 4x4 Toyota Tacoma TV with more antennae on it.