Dril-Quip offers either Pull-Up or Push-Up style, riser tensioning systems which are designed for stroke lengths, tensioning capacities and riser angular offsets compatible with Spars and TLPs.
All Dril-Quip Tensioning Systems feature the same highly-engineered, reliable and field-proven materials and components:
- Design life of 20-25 years
- Designed with the capability of operating in all riser modes with one cylinder out
- Low volume hydro-pneumatic cylinder takes advantage of a patented feature to minimize the size of the external accumulator
- Cylinder Barrel ID sealing surfaces are plated with engineered hard chrome for long life and tested in excess of 1 million cycles to simulate 20 years of cylinder movement (based on global riser analysis)
- Seals are a redundant, dual, elastomeric arrangement for long-life, high-pressure sealing
- Pressure relief devices are connected to accumulators to prevent over-pressurization of the cylinder accumulator assembly
- Stainless steel plumbing between the cylinders and the accumulators
- Tensioner Cassette Frame design optimized using FEA to minimize weight and improve fatigue life
- Dril-Quip offers two types of riser tensioning systems: pull-up style and Ram (push-up) style
- Strokes up to 30 feet and tensioner capacities up to 4,000,000 lbs.
- Push-up designs offered with Ram Style tensioner cylinders
Pull-up Style Tensioner
The heart of the tensioner system is the pull-up cylinder/accumulator assembly. The unitized assembly is comprised of a hydro-pneumatic cylinder, an external high-pressure accumulator, a low-pressure accumulator, and upper and lower-end connections.
- Pull-up tensioners offered in straight pull-up (mounted below cassette) or tendome (mounted above cassette)
- Offers benefits of traditional, field-proven, pull-up tensioner designs and includes spherical end bearings that allow up to 10° of angular misalignment between the riser and the platform
- Solid bar tensioner piston rod has external surfaces clad with a field-proven, cobalt-based alloy that is impervious to drilling/completion fluids and salt water spray
- Hydraulic control system, fluid maintenance cart and tensioner cassette are standard offerings for these systems
- Designed for Spar applications that have a keel and use a Keel Joint for centralization of riser
- Used when large strokes and high top tensions loads are present (typical of ultradeep Spar applications)
- Includes spherical end bearings that allow angular misalignment between the riser and the platform
- Both cylinders and HP accumulator are installed and serviced from the load structure