Pumping at work

Hello Working mummies, How often do you pump while at work? If you pump more than once, do you bring extra flanges and bottles? Or do you wash them and use it for round 2? What do you wash it with and how do you sterilize the bottles & pump flanges? Reason I asked if because am heading back to work soon. And not sure how flexible can it be, to be away pumping several times in a day. Appreciate your advices. TIA.