Page 410 - Pipeline Pigging Technology

Pigging through Yfittings

photograph of the test facility is shown in Fig.5. The test facility included the
following items:

1. air tank: steel tank with approximately 500gall capacity used to store
compressed air;
2. water tank: steel tank with approximately 600gall water capacity.
The water was drained from the tank and the extra capacity was
used to store compressed air during gas tests;
3. air valve: a 1 ii-in valve used to transfer air pressure to the water tank;
4. flow meters: turbine flow meters with 600gpm capacity used to
measure flow on each side of the wye;
5. inlet control valves: 3-in ball valves used to control flow from the
water tank into the transit spools;
6. chokes: chokes used to stabilize flow and regulate distribution
between transit spools (individually sized for the particular flow
conditions desired);
7. launcher: a 16-in (nom.) barrel, concentrically reduced to I4in
(nom.) and further concentrically reduced to lOin (nom.);
8. transit spools: approximately 20-ft long spools of 10-in pipe to allow
pigs to accelerate and reach a reasonably steady velocity before
entering the wye fitting;
9. piggable wye fitting: a lOin x lOin x lOin symmetric piggable wye
fitting;
10. receiver: a lOin x I4in x l6in barrel using concentric reducers to
transition diameters;
11. exhaust valve: a 4-in ball valve used to start and stop flow during
water tests;
12. drain tank: Steel tank with approximately 750gall water capacity;
13. Transfer pump: electric pump used to transfer water from drain
tank to water tank or piping;
14. pressure transducers: used to measure pressure at strategic loca-
tions during pigging tests;
15. recorders: three 2-pin recorders used simultaneously to record flow
rates (two each) and pressure readings (four each).

During typical water-driven pigging tests, there were three 2-pin recorders
used to make a record of pressures and flow rates vs time. One 2-pin recorder
was used to plot the flow rate in each side of the wye; a second 2-pin recorder
was used to plot the upstream and downstream pressures in the transit spool
on the side which contained the pig or pig train. The third 2-pin recorder was
used to plot the pressure on the outlet side of the fitting and the downstream

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