Equipment for the interconnection of two lines to allow running of pigs

A device for the interconnection of two flexible flow lines adapted to extend between a subsea production station and a surface facility to allow running of pigs from one line to another, said device comprising a modular crossover apparatus including a control valve connected between two curved pipelines and a pair of substantially Y-shaped connections insertable in said flow lines respectively with ends of said curved pipelines remote from said control valve being connected to said Y-shaped connection whereby upon selective actuation of said control valve to an open position, a pig can be launched from the surface facility through a first of said flow lines, passed through said crossover apparatus and returned through a second of said flow lines to clean said second flow line and push all debris back to said surface facility.