Patent ID: 8479774
Filing Date: 2013-07-09
Classification: E21B,F15B

Abstract:
1. An accumulator with a single directional seal on a piston which has a working fluid side and a compressed gas side and which can be exposed to a pressure differential from said working fluid side to said compressed gas side during normal operations and from said compressed gas side to said working fluid side when said piston moves to the end of its stroke, comprising a cylinder with a cylinder bore having said piston slidably moving along said cylinder bore and having a first piston area on said compressed gas side of said piston, a rod attached to the said working fluid side of said piston, said rod and said cylinder bore defining a second piston area smaller than said first piston area, said compressed gas being on said first side of said piston and said working fluid being on said second side of said piston such that the pressure in said fluid is equal to or greater than the pressure in said compressed gas due to the difference in surface areas, such that when said piston moves to the location of fully expelling said fluid out of said accumulator, the movement of said piston is stopped and the pressure of said working fluid can drop to a lower pressure than the pressure in said compressed gas, such that when said piston moves to the location of fully expelling said fluid out of said accumulator, said piston engages a second seal which can seal a pressure differential from said working fluid side to said compressed gas side.