Flexible Riser Equipment

Supergrip (UK) Ltd offer a range of equipment for the installation and repair of Flexible Flowlines.

Flexible Riser Repair System (FRS)

The FRS provides protection to the stainless steel internals of a flexible riser should damage to the outer sheath occur, typically in the free span between the splash zone and the platform. The FRS creates a seal that prevents ingress of the salt laden environment as well as a providing a low-pressure internal seal to enable the sheath to be vented.

The FRS comprises of three modules:

1. Axial Restraint Clamp sub-assembly

2. Inner Articulation sub-assembly

3. Outer Split Clamp sub-assembly

All modules are manufactured as a split design to enable them to be installed in-situ around the Flexible Riser. All components are manufactured from high integrity polyurethane with super-duplex fasteners for long-term application

The Axial Restraint Clamp provides the method of anchoring the system to the riser as well as creating the end seal to the assembly. The inner and outer articulation assembly provide the flexibility to the design ensuring the assembly can accommodate the dynamic movement of the riser. The articulation knuckles are a modular design meaning that varying lengths of damaged sheath can be protected. Each knuckle is fully sealed ensuring the system provides both internal and external pressure retaining capability.

Specification:

• cable diameters: 50mm to 400mm

• pressure capacity: 2 to 5 bar.g

Features:

• lightweight, flexible design capable of accommodating dynamic movement

• easy and reliable to assemble

* pressure sealing capability with no requirement for additional sealant.

Heavy Duty Riser Protection System

The Heavy Duty Riser Protection System offers three advantages over conventional systems:

1. increased impact resistance.

Following detailed Finite Element Analysis we will confirm the exact specification achieved by this size of product however from experience we are expecting between 30-60kJ

2. additional submerged weight for riser stability.

Due to the fact that flexible risers are buoyant when empty, the heavy-duty protection system has inherent weight to provide sufficient ballast for stability on the seabed. This prevents the need for installing concrete mattresses.

3. efficient installation methodology

as there will be approximately 1km of protection system to install the method of installation onto the riser needs to be optimised.

The Protection Element is a clearance fit on the flexible riser and is designed with a male knuckle one end and a female the other. The knuckle arrangement provides an interlocking feature that will withstand any axial forces during deployment and also provide a flexible design within the confines of the riser minimum bend radius

The Protection Element is a composite design with the inner core of the element being produced from a ductile cast iron. This provides sufficient mass to achieve the specific gravity required and is a cost effective method of manufacture. An outer polyurethane skin fully encapsulates the casting preventing exposure to seawater and eliminating the requirement for cathodic protection.

Specification:

• cable diameters: 50mm to 400mm

• impact resistance: 30kJ to 60kJ

• submerged specific gravity: 1.2 to 1.4 (riser with system installed)

• Fasteners: 1-off super-duplex fastener per knuckle

Features:

• split hinged design for a quick and efficient installation

• certified padeye on each knuckle

• axial restraint clamp provided to withstand installation forces

Guide Tube Centralization & Wear Protection

To protect the outer sheaths of Flexible Risers within guide-tubes, Supergrip have developed a centralization system that is installed with the Riser and offers a centralization and abrasion resistance to the Riser from the sea level down past the entry of the I-Tube.

The assembly comprises of lightweight knuckles that provides minimum bend radius protection together with centralization discs and distributed buoyancy modules.

The assembly is a clearance on the riser and the front knuckle provides a generous lead in taper to assist with installation into the guide tube.

The distributed buoyancy modules offer sufficient uplift to raise the assembly up to the waterline within the guide tube. The centralization discs provide the wear resistance and protect the flexible riser from dynamic movement.

Specification:

• cable diameters: 50mm to 400mm

• material selection: polyurethane and MDI foam buoyancy modules

• uplift force: project specific

Features:

• easy self-positioning installation

• modular design to accommodate varying lengths

• front and rear riser clamps provided to assist with deployment and installation.