Risers – SCR & TTR

Riser forgings

Subseatec produces a wide range of riser forgings such as special joints named stress joints, keel joints, transition joints, tension joints, extension joints, slick joints, telescopic joints, pup joints and many more. Covering a range of applications for drilling, production, water injection and workover systems. Length Adjustment Joints for TLP’s is another similar product Subseatec produces. 

All riser forgings can be delivered as raw material to you or as a truly turnkey delivery including, welding, finish machining including threads, coating, assembly, pressure testing. All based on your design and desired properties.

Standard joints

In addition to our Specialty Joints we are a well-known source for delivering standard joints either based on fully forged for special applications and we manufacture pin- and/or box end connectors, welded onto pipe and handle the full manufacturing execution to deliver fully tested joints ready for installation.

Specialty joints

Our Specialty Joints cover a range of applications for Drilling, Production, Injection and Workover Systems. 

Stress joints

A specialized riser joint designed with a taper to control curvature and reduce local bending stresses and often the riser exposed for highest loads in the string. Our Stress Joints in grade A707 3W have been supplied to recent Shell projects, e.g. Stones, Appomattox and Vito. 

Photo: Stress joints from Subseatec

Tension joints

The Tension Joint is a crucial part in any riser string and provides the means for attaching a vertical riser to the floating vessel’s tensioning system. Subseatec is a recognized source in supplying top quality Tension Joints. Subseatec’s Tension Joints are manufactured in different steel grades, but the most dominant is A182 F22 with yield strengths up to 85 ksi. We have established a good process to handle long and slender forgings up to 60 feet in one piece including large thickness variances meeting the toughest requirements.

Photo: Tension joints from Subseatec

Slick joints

A special riser joint being designed to prevent damage to the riser and control umbilical where they pass through the rotary table. Usually included in C/WO risers and many times named “cased wear joint”. Our references of this product are many with recent deliveries to Snorre B and the Luno projects. As an alternative to a painted carbon steel wear casing we can offer stainless steel solutions.

Photo: Slick joints from Subseatec

Transition Joints or Crossovers

The transition joint, typically named as a Crossover or Crossover joint, provides for the interface between two different coupling designs. We are familiar to any type of premium threads required on one or both sides of the crossover.

A pup joint is a standard joint, but shorter in length. The pup joints usually come in lengths of 10, 15 and 20ft. 

Other types of specialty joints manufactured by Subseatec: 

  • Pup joints
  • Telescopic Joints
  • Keel Joints
  • Extension Joints

Riser connectors

Subseatec produces shorter forgings such as pin & box connectors and flanges specifically optimised for welding onto pipes or other forgings while still meeting strength requirements.

The Connectors are typically delivered with different kind of surface treatments like cladding, HVOF and HVAF and any type of coating required, e.g. Thermal Sprayed Aluminium (TSA) or PTFE type coatings.


The Adapter is a pressure-containing piece of equipment with end connections of different nominal size designation and/or pressure rating.

Tension rings

Attachment point on the tension joint for the floating vessel tensioners, basically a support ring around the top of the joint where tensioner lines are attached. The tension ring is usually delivered together with the corresponding tension joint, but we do offer tension rings as a stand-alone item in any execution, ie the full tension ring system including bearings etc or the rough machined tension ring main body.