Double Jointing

The Double Jointer System is an equipment group that uses mechanized sub arc-welding processes to join two joints of pipe for shipment to the right-of-way.

The primary function of the Double Jointer System is to reduce in-the-field production time by having joints pre-welded before they arrive in the field. In a coordinated yard environment, pipe pairs can be joined into one unit at a much higher rate of speed than in the field. Exactly how much time is saved depends on the crew proficiency. Before pipe is moved into the Line-Up Station, their ends are prepared for welding. ID station welds the ID of the pipe. After the pipe pairs are joined, the double joint is moved onward to the Fill Stations. After additional passes have been applied, non-destructive testing inspects the pipe welds.

After pipes are joined, the double joints are moved outward onto customer storage skids for subsequent inspection, joint coating, and other operations.

Standard

The standard double jointer consists of: End Preparation Station, Line-Up Station, Cap Station, I.D. Station, Clean Out Station and UT or X-Ray Inspection Station.

Pipe flow through the system is by way of skidways and or transfer cars. Hydro-mechanical processes throughout the yard accomplish pipe positioning. Pipes handling and welding functions are controlled by use of push-button or joy stick controls. Floating welding heads are used at the Line-Up and Fill Stations.

A typical system consists of the following:

  • End Prep Station for increasing land on pipe bevel
  • Line-Up Station for pipe alignment and 1st external weld
  • Capping Fill Station for applying external weld cap
  • Internal Weld Station for applying internal weld
  • Power Trailer or containers with diesel generator and welding rectifiers (can be connected to utility power)
  • ( Lot ) Required pipe skids and supports for transferring the pipe from station to station
  • Internal Pneumatic Line-Up Clamps (customer to specify size)
  • Pipe Facing Machines (customer to specify size)

Note:

CRC-Evans recommends three (3) Pipe Facing Machines, two (2) of which are required for Double Jointer operation with one (1) as a standby.

CRC-Evans recommends two (2) Double Jointing Clamps with one (1) as a standby

Modified

CRC-Evans is able to custom design Double Jointer Systems for a customer specified application. This can include mechanical welding processes other than submerged arc additional inspection stations, automation options, or additional welding stations. We also have a reduced-cost system available for those applications that are not throughput driven, such as scrap reclaim to create full joints from remnants.