Abstract: An apparatus and method for pigging, flooding, and pressure testing pipelines utilizing a sliding sleeve valve connected at the end of a pig receiver which automatically opens upon fluid pressure in the pipeline reaching a predetermined limit allowing fluid trapped in the pipeline to escape, and is then automatically closed when the pig enters the pig receiver to allow pressure testing of the pipeline. The present apparatus and method eliminates the need and expense of a crew and/or a separate support vessel with divers or an ROV system at the downstream end of a pipeline during pigging, flooding, and pressure testing of the pipeline.