I think Rich is talking about a very different pressure system found on some old coaches where they used an air compressor to pressurize the potable water system.
With your water pump- based system there are two things you can do-- with different results:
Add an accumulator with bladder. Set PSI at 2 PSI less than cut-in pressure for the pump. For many, that means setting it at 23 PSI with city water off, pump off and pressure bled off by opening a faucet. This will do little to change the noise level, but help a lot in smoothing out water pressure at the faucets. The accumulator is generally plumbed into the system with a "T" after the outlet of the pump.
To quiet the pump, one needs to have the pump attached to the plumbing with a length of flexible hose, NOT hard pipe. This is both on the inlet and outlet. If plumbed with rigid pipe, the pump noise is transmitted through the pipes. This can normally be done for around $10 worth of hose, clamp and barb fittings. In fact some pump manufacturers suggest this flexible hose installation in their installation instructions. As an alternative, sometimes using foam rubber around the hard lines will help absorb some of the vibration-- it will not be as successful as isolating the pump with flexible hose, however.
Brett and Dianne Wolfe
2003 Alpine 38'
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