A pressure tank apparatus for use with a plumbing system of the like. The pressure tank apparatus includes a liquid storage vessel having a first end and a second end along with a curved side wall that extends between the first and second ends. The pressure tank apparatus also includes an inlet conduit connected to the liquid storage vessel along with an outlet conduit connected to the liquid storage vessel. The pressure tank apparatus also includes a valve cap connected to the liquid storage vessel and a first cut-off valve connected to the inlet conduit along with a second cut-off valve connected to the outlet conduit.