Method of cooling coated pipe

A method of forming a hot plastic coating on pipe lengths and subsequently cooling said coating, comprising the steps of:

• providing pipe lengths each having an axis, and a coating application station that forms a hot plastic coating on said pipe lengths when conveyed successively therethrough;
• providing a conveying device for conveying said pipe lengths continuously, longitudinally, and successively through said coating station in a longitudinal direction parallel to the axis of each pipe length in such manner that a gap exists between adjacent pipe lengths at a region spaced longitudinally from said coating station;
• providing a cooling medium supply device running within a pipe length adjacent said coating station, said cooling medium supply device running within the pipe length on roller members inclined relative to the axis of the pipe length so that the cooling medium supply device maintains a stationary position relative to features outside the pipe length, said cooling medium supply device comprising a cart carrying a pressurized reservoir and a recharging lance extending from said reservoir in said longitudinal direction;
• providing a recharging apparatus permitting passage of said pressurized cooling medium therethrough and reciprocating parallel to said longitudinal direction and having a coupling portion movable between a retracted position spaced laterally outwardly from said pipe lengths and an extended position wherein said coupling portion aligns with said recharging lance;
• conveying said pipe lengths on said conveying device continuously and successively through said coating station to apply a hot plastic coating on said pipe lengths;
• cooling said coating by applying said cooling medium continuously to an interior surface of each successive pipe length while downstream from said coating station, said cooling medium being supplied from said pressurized reservoir of said cooling medium supply device;
• and
• intermittently recharging said pressurized reservoir by moving said coupling portion, when adjacent said gap between adjacent pipe lengths, to said extended position, moving said recharging apparatus together with said coupling portion in a first longitudinal direction to engage said coupling portion with said lance, flowing said pressurized cooling medium through said recharging apparatus to recharge said reservoir, moving said recharging apparatus in a direction opposite said first longitudinal direction to disengage said coupling portion from said lance, and moving said coupling portion to said retracted position.