Burped GV7's gate annulus volume into annulus ion pump only instead of pump cart-only minor bump in ion pump current -> valved-out XBM turbo  -> opened GV7 -> Burped GV20's gate annulus volume into pump cart - pegged ion pump current briefly -> Valved-out pump cart and verified that ion pump could handle gas load with gate annulus valved into ion pump -> closed gate annulus isolation valve -> Disconnected pump cart from annulus plumbing -> Valved-out X-end turbo -> Opened GV20