ISO 5625:1978

Overview

ISO 5625:1978 is an international standard developed by ISO Technical Committee ISO/TC 8, focused on shipbuilding components-specifically welded bulkhead pieces with flanges for steel pipework. The standard addresses the main manufacturing dimensions for bulkhead pieces designed for pressure nominal ratings of PN 6, PN 10, and PN 16. These welded bulkhead pieces are critical for creating secure passages through ship bulkheads and decks, ensuring reliable support and connection for steel pipelines in marine environments.

This standard specifies not only the manufacturing dimensions but also the corresponding openings required in bulkheads and decks to accommodate these pieces. It exclusively covers components that are fabricated and attached by welding and utilizes flanges compliant with ISO 2084, which details metric series pipeline flange mating dimensions.

Key Topics

• Scope & Application
  ISO 5625:1978 applies strictly to welded bulkhead pieces that interface with flanged steel pipework where nominal pressures are PN 6, PN 10, or PN 16. The document excludes specifications on flange types, welding methods, or radii of butt-welding bends, leaving these details to relevant project or regulatory requirements.

• Types of Bulkhead Pieces
  The standard identifies two main types:

  • Type A: Bulkhead pieces with flanges on both sides, suitable for pipe connections via flanges on either side of the bulkhead or deck.
  • Type B: Bulkhead pieces with a flange on one side and a welded connection on the other; accommodates either straight pipes or butt-welding bends.

• Dimensions & Designation
  Precise dimensional data for pressure ratings PN 6, PN 10, and PN 16 includes parameters such as lengths (L1, L2), diameters (D2, D3), and thicknesses (t). The standard includes detailed tables listing these dimensions for nominal pipe sizes (DN). Bulkhead pieces are designated by the format:
  [ISO 5625](/search?q=ISO%205625) - PN - DN - Type
  e.g., [ISO 5625](/search?q=ISO%205625) - 16 - 250 - B.

• Installation Considerations
  The standard advises adjustments to dimensions L1 and L2 to account for insulation thickness where bulkheads or decks are insulated. Material selection for sleeves, collars, and weld filler must consider adjacent space temperatures and fluid transmission.

Applications

ISO 5625:1978 is crucial for shipbuilding and marine engineering projects involving steel pipework under pressure. Its applications include:

• Designing and fabricating welded bulkhead passages that maintain structural integrity while allowing fluid conveyance through pressure-tight connections.
• Ensuring compatibility with standardized flanges per ISO 2084 for seamless pipework assembly.
• Facilitating proper sizing and placement of openings in ship bulkheads and decks for pipeline penetrations.
• Enhancing safety and regulatory compliance in ship's pressure pipe systems by adhering to standardized dimensions and pressure ratings.

By standardizing welded bulkhead pieces with flanges, ISO 5625 helps shipyards and manufacturers minimize fabrication errors, improve interchangeability, and support maintenance and inspection operations on marine pipelines.

Related Standards

• ISO 2084 - Pipeline flanges for general use-metric series mating dimensions, which defines the flange types compatible with the bulkhead pieces described in ISO 5625.
• Additional shipbuilding and pressure piping standards relevant for structural integrity, welding specifications, and insulation requirements might apply depending on jurisdiction and project scope.

Keywords: ISO 5625, shipbuilding standards, welded bulkhead pieces, steel pipework, flanges, PN 6, PN 10, PN 16, maritime pipelines, pipe flange dimensions, ship bulkhead passages, welded pipe fittings.