In many reciprocating compressor installations the pulsation dampers have integral moisture removal sections to provide a final line of defense against liquid carryover. There are two schools of thought. Pulsation dampers can be designed with these moisture removal sections, or they can be designed so that liquids positively cannot collect. Most refinery pulsation dampers have moisture removal sections. Many oil field dampers do not have moisture removal sections.
Designing pulsation dampers without moisture removal sections takes great care when the damper includes internals for pulsation attenuation (choke tube and baffle). The baffle needs to have a hole at the bottom to prevent liquid from accumulating on either side. However, a hole in the baffle can make the damper less effective as an acoustic filter. The way around this is to design the damper with an additional choke tube at the bottom of the damper and acoustically model the damper in this configuration. Another problem is the lip created by the nozzle projecting into the bottle. Figure 300-65 illustrates the design aspects.