The Collaborative International Dictionary of English v.0.48:

Standpipe \Stand"pipe`\ (-p[imac]p`), n.
   1. (Engin.) A vertical pipe, open at the top, between a
      hydrant and a reservoir, to equalize the flow of water;
      also, a large vertical pipe, near a pumping engine, into
      which water is forced up, so as to give it sufficient head
      to rise to the required level at a distance.
      [1913 Webster]

   2. (Steam Boiler) A supply pipe of sufficient elevation to
      enable the water to flow into the boiler, notwithstanding
      the pressure of the steam. --Knight.
      [1913 Webster]

WordNet (r) 3.0 (2006):

standpipe
    n 1: a vertical pipe

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "standpipe":
   adjutage, antenna tower, barbican, belfry, bell tower, campanile,
   catheter, colossus, column, cupola, derrick, dome, drainpipe,
   efflux tube, fire hose, fire tower, flue pipe, funnel, garden hose,
   gas pipe, hose, hosepipe, lantern, lighthouse, martello,
   martello tower, mast, minaret, monument, nipple, obelisk,
   observation tower, organ pipe, pagoda, pilaster, pillar, pinnacle,
   pipe, pipeline, pipette, piping, pole, pylon, pyramid, reed,
   reed pipe, shaft, siamese, siamese connection, siphon, skyscraper,
   snorkel, soil pipe, spire, steam pipe, steeple, stem, straw, stupa,
   tap, television mast, tope, tour, tower, tube, tubing, tubulation,
   tubule, tubulet, tubulure, turret, waste pipe, water pipe,
   water tower, windmill tower