General construction of a Bonded Production Flexible Line
The flexible lines are a bonded construction comprising steel and elastomeric materials. The principal characteristic of bonded construction is the build-up of individual layers in the flexible hose wall which are then combined into one unit through vulcanisation. Hose assemblies are manufactured as a single bonded unit to specified lengths where the couplings are a chemically bonded integral part of the hose.
- Stainless steel interlock stripwound tube
Protects the polymer lining from mechanical damage, prevents blistering in case of high pressure gas service and decompression with vacuum service, supports the wall of the flexible hose and facilitates pigging. The material can be AISI 316L or 254 SMO grade stainless steel, depending on the conveyed medium.
- Polymer lining
Fluid barrier of the flexible line. Protects the hose construction from corrosive and abrasive effects of the conveyed medium. The thickness of lining depends on the internal pressure, the inside diameter and the conveyed medium. The lining material is selected to withstand chemical and heat effects of crude oil, seawater, gases, hydraulic fluid or whatever substance is conveyed through the hose.
- Textile plies
To distribute the forces of internal pressure.
- Stiffening spiral (not shown in the picture)
To protect the hose against collapse under axial pulling force and/or as a result of external pressure. Prevents kinking even in sharp bends.
- Elastomeric cushion plies
To ensure adhesive bonding between different plies.
- High strength steel cable reinforcements
These are the most important load-bearing elements, they determine internal pressure resistance. The cables are either zinc or brass coated to provide exceptional corrosion resistance.
- Gas leading plies
To allow diffused gases to migrate to venting points.
- Fire resistant plies
Protects the hose in case of exposure to flame at 704°C (1300°F) for at least 30 minutes.
- UV resistant elastomeric cover
Protect the flexible hose line from impact, abrasion, weather, seawater, oil, etc.
- Outer stainless steel stripwound protection
Protect the hose against external mechanical damage, material AISI 316L.