Comparison of Relative Emissions from Double Mechanical Pump Seals to other Types of Pump Shaft Seals

摘要

The report gives results of a comparison of pump seal data from nine petroleum refineries, to evaluate emissions from double mechanical pump seals versus those from other types of pump shaft seals. Light- and heavy-liquid service seals were compared separately. Non-methane leak rates for single and double seals were compared using schematic plots. Centrifugal/mechanical pump, centrifugal/packed pump, and reciprocal/packed pump leak rates were also compared using schematic plots. The percentages of seals leaking and 95 percent confidence intervals about the percentage leaking were calculated to evaluate the tendency for pump shaft seals to leak. In all cases, the confidence intervals for the three types of pumps overlapped, indicating no significant difference between pump types for either single or double seals and light- or heavy-liquid service.