Double carcass mainline hose is born with a leak detection system, which will remind the operator that the primary carcass has failed. This kind of hose structure provides a safer working condition.
Mainline hoses are the main part of the floating transfer line on the ocean surface. The longer the entire line is, the larger the proportion of mainline hoses is.
The primary carcass is surrounded by the second carcass, but they are manufactured and inspected independently. When the inner carcass burst or leak, the outer carcass won't be affected. It will continue to work as normal and react to the failure, such as showing the red warning light, so that the operator can handle the damaged hose in time. Double carcass structure not only improves work safety, but also decrease the probability of economic loss and environmental pollution.
When the primary carcass fails, fluid will flow to the second carcass instead of entering the sea water. Although the remained carcass can function up to many years, damaged parts should be removed and replaced as soon as possible. Otherwise, accidents can show up anytime.
Natural gas transfer project in Indonesia (10×10"×11.8m×10 bar)
→Inner layer: Synthetic rubber
Feature: Resistant to crude oil; Smooth
→Reinforcement: Multiple layers of high-strength textile cords + Embedded spiral steel wire
→Outer layer: Synthetic rubber; Spiral orange stripes on the surface
Feature: Smooth; Resistant to abrasion, oil, weather, sea water, and sunlight/UV ray
→Floating material: Polyethylene closed-cell foam
→Minimum burst pressure
Primary carcass: 5 × Rated Working Pressure
Secondary carcass: 2 × Rated Working Pressure
→Fittings: ASME B 16.5 (Class 150, 300, 400, 600, 900, 1500, and 2500) or other standards flanges according to customer's request will be welded on the raised face, flat face, or other required face of the hose neck. Flange material options include carbon steel and stainless steel. There are several welding and sealing methods for you to choose.
→Flange standard: ANSI, GB, JIS, or DIN.
Test Report & Technical Analysis
Import the ABAQUS static analysis results into the fatigue analysis software fe-safe, select the fatigue analysis theory, set the material parameters of each structural layer, load the above load spectrum, and we can get the fatigue analysis results.
We use finite element analysis software ABAQUS to:
- Create a detailed local model of the hose to calculate hose strength, such as cord tension, rebar stress, rubber strain
- Build a detailed hose model and calculate the bending, tensile and torsional stiffness of the hose
- Calculate cord tension, rebar stress, and rubber strain under certain loads
When designing marine hoses, we do dynamic analysis and hydrodynamic calculations with the help of OrcaFlex. Dynamic responses of marine hoses are simulated under environmental loadings like wind, currents, and waves. For hoses are applicated in mooring systems like SPM, we analyze tension of mooring lines in different sea states and mooring point’s motion and displacement under various dynamic loads.
