This paper introduces an adaptive parallel pipeline pattern which follows the GRASP (grid-adaptive structured parallelism) methodology. GRASP is a generic methodology to incorporate structural information at compile time into a parallel program that enables it to adapt automatically to dynamic variations in resource performance. GRASP instruments the pipeline with a series of pragmatic rules, which depend on particular performance thresholds based on the computation/communication patterns of the program and the availability of resources in the grid. Our parallel pipeline pattern is implemented as a parameterisable C/MPI API using a variable-size input data vector and a stage function array. We have evaluated its efficiency using a numerical benchmark stage function in a non-dedicated computational grid environment.