GB/T 19317-2024 Small craft - Seacocks and through-hull fittings
1 Scope
This document specifies requirements for through-hull fittings, seacocks, hose connections, their fittings and their installation in small craft with a length of hull, LH , as defined in ISO 8666:2016, of up to 24 m.
This document is not applicable to engine and heater exhaust fittings, and sail drive through-hull fittings.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 16422.3-2022 Plastics - Methods of exposure to laboratory light sources - Part 3: Fluorescent UV lamps
ISO 65091:2014 Corrosion of metals and alloys - Determination of dezincification resistance of copper alloys with zinc - Part 1: Test method
ISO 65092:2017 Corrosion of metals and alloys - Determination of dezincification resistance of copper alloys with zinc - Part 2: Assessment criteria
ISO 14993:2018 Corrosion of metals and alloys - Accelerated testing involving cyclic exposure to salt mist, dry and wet conditions
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
through-hull fitting
device fitting designed to permit passage of liquids including suspended solids or gases through the hull
3.2
seacock
shut-off device intended to prevent the ingress of water, normally directly fitted to a hull or a through-hull fitting
3.3
accessible
capable of being reached for inspection, removal or maintenance without removal of permanent craft structure
3.4
readily accessible
capable of being reached quickly and safely for effective use under emergency conditions without the use of tools
3.5
maximum load waterline
waterline of the craft when upright in the fully loaded ready-for-use m LDC condition
Note: The fully loaded ready-for use condition is defined in ISO 8666:2016, 6.3.
3.6
heeled waterline
level of the water on the hull in the fully loaded ready-for-use m LDC condition when the craft is inclined to
——7° for motor boats and sailing multihulls; or
——30° or immersion of the sheerline, whichever occurs first, for monohull sailing boats
Note: The fully loaded ready-for use condition is defined in ISO 8666:2016, 6.3.
3.7
hose fitting
component used to connect a through-hull fitting or a seacock to an associated hose
4 Material requirements
4.1 General
Materials used for through-hull fittings, seacocks, hose connection and fittings located below the maximum load waterline shall be corrosion-resistant.
Materials used above the waterline shall be corrosion resistant or shall have protection against corrosion, taking into account the various and changing media that pass through the fitting (for example fresh, salt or brackish water with impurities; waste water from toilet systems or holding tanks).
Brass materials shall be dezincification resistant (DZR) when tested in accordance with ISO 6509-1:2014 and assessed in accordance with ISO 65092:2017.
4.2 Material combinations
The combination of different materials including fastening elements shall take into consideration the possibility of galvanic action.
Materials that act galvanically with others used in the system may be used if they are galvanically isolated.
The combination or choice of non-metallic materials shall be made taking into account the possibility of swelling and/or seizure.
Materials in contact with each other shall not prevent the device and/or system from acting as intended.
Non-ferrous metals other than aluminium alloys shall not be used when aluminium is incorporated in the system.
4.3 Resistance to deterioration/corrosion tests
All metallic components shall be corrosion resistant. The requirement for corrosion resistance shall be met through testing as per Annex B.
All non-metallic parts shall be stabilized against oxidation and UV. The requirement for UV stabilisation shall be met through testing as per Annex C.
4.4 Strength requirements
Seacocks, through-hull fittings and hose fittings shall fulfil the requirements of the strength test according to Annex A.
4.5 Range of operating temperatures
4.5.1 General operating requirements
Seacocks and through-hull fittings shall be operable through the full temperature range of 0 °C to + 60 °C and shall show no defect that will impair the function.
4.5.2 Storage temperature requirement
Seacocks and through-hull fittings shall withstand a storage temperature without operation of –40 °C to +60 °C when kept dry.
4.5.3 High temperature operating test
Seacocks shall be filled with water and, after preconditioning for 24 h at 60 °C, shall be operable.
4.5.4 Low temperature operating test
Seacocks shall be filled with salt water and, after preconditioning for 24 h at 0 °C, shall be operable.
Note: Salt water test liquid is defined in ISO 14993:2018, Clause 4,
