eSubsea design and manufacture cost effective suction anchor vent hatches, also known as vent caps or ventilation hatch covers. The vent hatches are used to expel water and air during installation and to seal under- and overpressure during installation and retrieval of suction anchors, caissons or piles. The no-leak sealing technology for installation is field proven and reliable and praised by the ROV operators as easy to open and close. It can be applied to any interface, such as bolted flanged or weld neck.

Suction Pile Ventilation Hatch

The suction pile ventilation hatch is a standard subsea product which is available in any nominal bore (normally 0.5 to 1 meter in diameter) and for any water depth (3000 meters). The design pressure range is down to -20 bar and up to +20 bar to account for deepwater effects, high penetration resistance during installation and future removal and decommissioning pull-out requirements. The design life for subsea application is 30 years using both carbon steel and stainless steel, sacrificial anodes for corrosion protection combined with NORSOK system 7B paint and electrical continuity for all parts. 

Vent Hatch for Offshore Wind Mooring

The suction anchor hatches are specially designed for offshore wind mooring. With the requirements for silent, quick and easy installation, cost reduction and higher load capacity, these vent hatches are optimized for cost and high under- and overpressure.

Suction Anchors and Vent Hatch for Any Applications

Our suction anchors and suction vent hatches can be used as support, mooring and anchoring for typical applications such as:

  • Deepwater applications
  • Drilling rigs and floating offshore platforms
    • TLP (Tension Leg Platforms)
    • Semi Submersible
    • SPAR
  • Floating offshore wind foundations
    • TLPs
    • Semi Subs
    • SPARs
    • Buoys for electrical cables
    • High Buoyancy Applications
  • Aquaculture structures
    • Fish farms (Salomon, Trout, Cod etc.)
    • Fish cages
  • Solar energy floating system
    • Solar panels farms
  • Underwater equipment
    • Pipelines
    • Buoys
    • Wellhead load relief systems
    • Underwater monitoring
    • Testing equipment
  • Ships, docks, berths, pontoons and more

eSubsea and our partners can deliver subsea products, concept studies, engineering and design services and offshore and underwater hardware to the North Sea, Gulf of Mexico, Canada, Australia, West of Africa, Brazil and Russia

Design of Suction Anchor Vent Hatch

The suction anchor vent hatch is designed with focus on simplicity, low cost and high reliability. It basically consists of a hatch neck with 3 off supports, a lid with 3 off ROV operated handles and a main hinge. The handles are used to engage the hatch lock bars on the lid. 

Suction Anchors - eSubsea
Suction Anchor with vent hatches

Installation and Landing Calculations

The open vent area must be calculated to ensure that there are sufficient openings for expelling air and water during installation to avoid slack slings and local scour and wash out. The acceptable landing speed should always be limited, but this is not always practical. eSubsea can assist you with all necessary calculations and assessments.

All required documentation such as fabrication drawings, design reports, corrosion protection report, lift test procedures, installation and retrieval procedure are included in the suction anchor engineering package. On delivery, a certificate of conformance will be issued. If the purpose of the suction anchor is temporary, a storage and maintenance manual will be included.

The DeepWater Suction Anchor

eSubsea is developing and patenting a new type of suction anchor that is aimed at the rapidly growing offshore wind market. The new type of anchor will significantly reduce cost directly and also have increased pull out and holding capacity compared to cost. It is particular effective for deepwater TLP applications. This new game changing mooring solution is currently being designed and patented and will be launched as soon as the results are confirmed and patents filed.

Mooring and Anchoring Concept Study

eSubsea with its engineering and geotechnical partners can carry out fast track concept and feasibility studies which include concept evaluation, preliminary suction anchor sizing based on input loads, penetration resistance and required suction, bearing capacity and skirt wall thickness. The concept study is a cost effective way to quickly establish size, weight, budget cost and delivery schedule for your project.