Patent ID: 11920720
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F  E | IPC E  F

Claim 10:
11. A water hammer mitigation method comprising:
flowing fluid through a main pipeline, the main pipeline in communication with a pressure source, the main pipeline having a shutdown valve downstream of the pressure source, and first and second ends of a branch pipeline coupled to the main pipeline, the branch pipeline having a bi-directional surge relief device between the first and second ends;
the bi-directional surge relief device comprising
a housing with a first end proximate the branch pipeline first end and a second end proximate the branch pipeline second end,
a first cavity in the housing adjacent the housing first end and a second cavity in the housing adjacent the housing second end,
a first flow channel extending through the housing between the first cavity and the housing second end,
a second flow channel extending through the housing between the second cavity and the housing first end,
a first relief valve in the first cavity that is moveable into a first open configuration when a pressure differential across the relief device exceeds a first predetermined threshold pressure and so that the housing first and second ends are in fluid communication through the first flow channel and the first cavity, and
a second relief valve in the second cavity that is moveable into a second open configuration when a pressure differential across the relief device exceeds a second predetermined threshold pressure and so that the housing first and second ends are in fluid communication through the second flow channel and the second cavity;

maintaining the bi-directional surge relief device in a closed configuration to prohibit fluid flowing in the main pipeline from flowing through the branch pipeline in response to pressure at a surge point on the main pipeline being between a predetermined vacuum pressure threshold and a predetermined surge pressure threshold, wherein the first predetermined threshold pressure across the relief device corresponds to the predetermined surge pressure threshold at the surge point, and wherein the second predetermined threshold pressure across the relief device corresponds to the predetermined vacuum pressure threshold at the surge point, wherein the first end of the branch pipeline is fluidly coupled to the main pipeline at the surge point on the main pipeline and the second end of the branch pipeline is fluidly coupled to the main pipeline at a distal point on the main pipeline that is distal to the surge point;
operating the bi-directional surge relief device to move the first relief valve to the first open configuration to permit fluid flowing through the main pipeline to flow via the branch pipeline from the first end to the second end and into the main pipeline via the distal point, in response to the pressure at the surge point on the main pipeline reaching the predetermined surge pressure threshold; and
operating the bi-directional surge relief device to move the second relief valve to the second open configuration to permit fluid flowing through the main pipeline to flow via the branch pipeline from the second end to the first end and into the main pipeline via the surge point, in response to the pressure at the surge point on the main pipeline reaching the predetermined vacuum pressure threshold.