Abstract: A temporary trap door cap device for sealing around a pressure-leaking trap door at an end of a pipeline terminating in a trap includes a canister formed from a longitudinally extending pipe having an open end and a closed end; and an annular rim connected to the open end, with an inner diameter smaller than an inner diameter of the canister. The annular rim is configured such that the inner diameter of the annular rim fits over the trap door of the trap terminating the pipeline. After the annular rim has passed over the trap door, the inner diameter of the annular rim is compressible against a body of the trap terminating the pipeline so as to seal an inner volume of the canister pressure-tight thereby containing the trap door within the pressure-tight volume.

Abstract: A trap door cap for sealing around a trap door of a trap is disclosed. The canister includes a closed end and side walls extending from the closed end, wherein the side walls and the closed end together define a cup-shaped body having an open end opposite the closed end. The trap door cap further includes a seal configured to selectively apply a pressure-tight seal around an exterior surface of the trap at a longitudinal location of the trap inward of the trap door and a pressure-tight connection between the seal and the open end of the cup-shaped body, wherein the side walls, the closed end, the seal, and the pressure-tight connection together form a pressure-tight inner volume within the canister.

Abstract: A temporary trap door cap device for sealing around a pressure-leaking trap door at an end of a pipeline terminating in a trap includes a canister formed from a longitudinally extending pipe having an open end and a closed end; and an annular rim connected to the open end, with an inner diameter smaller than an inner diameter of the canister. The annular rim is configured such that the inner diameter of the annular rim fits over the trap door of the trap terminating the pipeline. After the annular rim has passed over the trap door, the inner diameter of the annular rim is compressible against a body of the trap terminating the pipeline so as to seal an inner volume of the canister pressure-tight thereby containing the trap door within the pressure-tight volume.