Piping system liquid mass, viscosity, length, diameter, make flow fluctuation into pressure pulsation
PIPE PROBLEMS: 1, 2, 3 (below)
Reverse Osmosis "RO" systems, like many other systems, are packaged and have short pipes. Short pipes, like short anythings, have natural HIGH FREQUENCIES

TECH Notes: it is not necessary to read the areas shaded in this color. RPM x Number of displacers x 2 (because there is a secondary bump from the overlap of one displacer tot the next) x say a minimum of 3 valve beats, then all divided by 60 (60 seconds in a minute), = flow fluctuation forcing frequency in Hertz, abbreviation "Hz". Compare this figure with eh system you chose, is roughly according to the effective compressibility, 4600 ft/sec divided by twice pipe length ft. (end & back). Or 1400 / 2 x M = Min. Acoustic Hz. PUMP Hz. PIPE Hz is never to be a whole Number

1. The water was not pure.
2. The pipes vibrated, the shaking made more pressure spike, the pipe spikes built on the pump spikes & amplified
3. Now the high amplitude at high frequency robbed 70% of the life from the ultra filtration membrane.

RESULTS: 1, 2, 3, & 4
1. Four times the ultra filtration membrane life.
2. The water was pure
3. The system stopped springing leaks.
4. EVEN BETTER
When a PumpGuard cavitation preventor was added to suction it, it was possible to double the flow rate by changing the driven pulley.
*8.8 Meters, say 57.7 feet there and back, at 4600 ft in a second, dived by 57.7 ft. = 79.7 acoustic/pressure waves coming back onto the pump per second. They return at almost the exact instant the pump tries to send out another one. The system is an amplifier.
That is one reason for RESONANCE.

PUMPS MAKE FLOW, & flow fluctuations, SYSTEMS MAKE PRESSURE, & PRESSURE PULSATION; ask pump people about flow, ASK DAMPER PEOPLE about pressure pulsation

High Hz. - Comments Liquid Dynamics International by - "Pulse-Doctor" Analytical, Diagnostic and Software services