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minimize the outlet pressure and flow variation, as well as desiccant shock as the flow
switches from one chamber to the other.
The
PCR model
also utilizes a re-pressurizing timer. It maintains a 2-minute cycle, with
a 7-second re-pressurizing period prior to switching towers. The
PMD and TOC models
follow a standard 1-minute cycle like the PHF300A model.
The timer wiring diagrams for all models are shown in Figure 8.
PCR
Model
PHF,
PCDA, PHCA & PCME Models
PMD and TOC Models
FIGURE 8: WIRING DIAGRAMS
Operating Pressure and Sizing
Most PUREGAS models are designed to operate at pressures up to a maximum of 150
psig. The only exceptions are the PMD and TOC models, which have a maximum
operating pressure of 125 psig. It is important to note that all models based on PSA
technology will achieve better performance at higher operating pressures. Therefore,
any pressure regulation should be done downstream of the dryer or adsorber.
