Acoustic velocity or sound is a most important consideration in a pulsation dampening system. Pulsations, traversing a piping system, travel at about the gas sound speed. Generally, heavy gases have a slower pulse speed and lighter gases a high pulse speed. For the same compressor speed, a heavy gas has a shorter pulse wave length. Shorter wave lengths result in smaller pulse controllers. For example, hydrogen is a light gas with long pulse wave lengths requiring large pulse controllers. Techniflo analyzes gas sound speed when sizing your pulse controller.
Pulsation in air and gas is always present in reciprocating compressor systems. Specifications for residual pulsation are necessary to guide engineers. As the pressure is increased, a lower allowable pulsation percentage should be specified. The chart shows teh current specification of the American Petroleum Institute giving the maximum residual allowable pulsation (peak to peak) versus absolute line pressure.
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