Accumulator for an engine exhaust treatment system

An exhaust treatment system for an engine, the system comprising:

• a bulk tank for storing exhaust treatment fluid;
• a transfer pump configured to pump exhaust treatment fluid from the bulk tank;
• an accumulator having an inlet portion that receives exhaust treatment fluid from the transfer pump;
• an exhaust treatment fluid injector;
• a dosing pump configured to withdraw exhaust treatment fluid from the inlet portion of the accumulator and provide exhaust treatment fluid to the exhaust treatment fluid injector;
• an outlet portion of the accumulator operably coupled to the bulk tank to permit exhaust treatment fluid to return to the bulk tank;
• and
• a weir of the accumulator separating the inlet and outlet portions of the accumulator and permitting exhaust treatment fluid in the inlet portion to flow to the outlet portion.

A method of operating an exhaust treatment system for an engine, the method comprising:

• pumping exhaust treatment fluid from a bulk tank into an accumulator;
• drawing exhaust treatment fluid from the accumulator to a dosing pump;
• returning exhaust treatment fluid from the accumulator to the bulk tank;
• and
• injecting exhaust treatment fluid into an exhaust stream of the engine.