Diverting pigs in a pipeline or piping system
AssigneeSubsea 7 Norway AS
InventorOivind Stangeland
Life of this patent
Estimating the term…
Abstract
A pig diverter comprises a hollow housing having a flowline inlet port, a flowline outlet port, a pig entry opening, and a pig exit opening, all communicating with the interior of the housing. A tubular pig holder enclosed by the housing is pivotable between a receiving position and a launching position. In the receiving position, the pig holder is aligned with the pig entry opening to receive a pig and effects fluid communication between the pig entry opening and the flowline outlet port. In the launching position, the pig holder is aligned with the pig exit opening to launch a pig and effects fluid communication between the flowline inlet port and the pig exit opening.
Claims30
A pig diverter, comprising:
- a hollow housing having a flowline inlet port, a flowline outlet port, a pig entry opening and a pig exit opening, all communicating with the interior of the housing, wherein the pig entry opening and the pig exit opening are disposed on respective sides of a longitudinal axis of the housing and communicate with the interior of the housing through respective opposed ends of the housing;
- and
- a pig holder enclosed by and movable within the housing between a receiving position and a launching position, wherein the pig holder is a tube that extends along the housing and the opposed ends of the housing are positioned to close opposed ends of the tube, the pig holder being mounted to the housing or pivotal movement about a pivot axis between the receiving position and the launching position;
- wherein, when in the receiving position, the pig holder is aligned with the pig entry opening to receive a pig;
- and
- when in the launching position, the pig holder is aligned with the pig exit opening to launch a pig and effects fluid communication between the flowline inlet port and the pig exit opening;
- and
- wherein a flow path is defined within the housing outside the pig holder, in a space between the housing and the pig holder.
A method of diverting a pig, comprising:
- when a pig holder is on a receiving axis,
- directing a flow of fluid from a pigging path outlet to a flowline outlet port, and receiving the pig into the pig holder from the pigging path outlet;
- moving the pig holder and the received pig from the receiving axis onto a launching axis;
- directing a bypass flow of fluid around the pig holder within an enclosure in which the pig holder is movable between the receiving axis and the launching axis;
- and
- when the pig holder is on the launching axis,
- directing a flow of fluid from a flowline inlet port to a pigging path inlet via the pig holder, and
- launching the pig from the pig holder into the pigging path inlet.
Dependencies are inferred from the claim text.