Page 418 - Pipeline Pigging Technology

Pigging through Y fittings

Fig.9. Kick-off pressure vs pig squeeze for F.H.Maloney sphere.
the Conoco Jolliet project, one test program performed for Transcontinental
Gas Pipe Line Corporation, and one performed by HydroTech Systems.
Throughout these tests, subtle changes occurred in the ID of transit spools,
that can have an effect on the differential pigging pressure. The sensitivity of
pigs to changes in pipe ID is demonstrated in Figs 9 and 10. These results show
that differential pigging pressures for an F.H.Maloney sphere and a
S.U.N.Engineering squeegee (cup-type) pig are affected dramatically by the
squeeze on the pig. Some of the pigging tests also had the presence of
lubrication effects which reduces the required differential pigging pressures.
Results of testing for specific pigs are presented in Tables 2 through 11.
Tables 2 through 8 show results for tests conducted using water, while Tables

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