SIST EN 13078:2004

SIST EN 13078:2004 is the SIST adoption of EN 13078:2003 for air gaps with submerged feed incorporating air inlet plus overflow, Family A, type C. It specifies the characteristics, materials, construction details and tests for devices that protect potable water in water installations from backflow pollution. It applies to factory-assembled products and to air gaps constructed in situ.

What does SIST EN 13078:2004 specify?

SIST EN 13078:2004 covers the characteristics and requirements for Family A, type C air gaps and the way they are identified and tested. The document is organized into scope, normative references, terms and definitions, symbolization, designation, materials, requirements, marking and technical documents, with Annex A giving the vacuum test.

The scope also states that the standard defines the physico-chemical characteristics of construction materials used for this application. In practice, that means the material choice and the device layout both matter for keeping the potable water side protected during normal use.

What are the key requirements of SIST EN 13078:2004?

SIST EN 13078:2004 focuses on material suitability, stable construction, a defined air gap, verification by test and clear marking. The requirements are written so manufacturers, installers and test labs can check whether the device will maintain separation between potable water and the contaminated side.

Materials and designation

Clause 5 sets the designation format: name, family and type, denomination (DN or D) and the standard reference. That matters when a buyer or engineer needs to specify exactly which air gap is being ordered or documented.

Clause 6 requires the manufacturer to state the material type in technical and commercial documents, and the materials in contact with drinking water to comply with applicable European and national acceptance rules. The materials must also be compatible with each other, with the supplied water and with any substances they may encounter.

Construction and overflow arrangement

Clause 7 says the protection assembly is made up of a water inlet device, a receiving vessel, an air inlet orifice and an overflow. The inlet device and its feed pipe must be fixed securely, the air inlet orifice must stay above the maximum level, and submerged supply pipes need corrosion-resistant materials and pressure testing.

The overflow arrangement must include an air break to drain and meet the relevant requirements of EN 1717. In practice, the overflow must work as a safe discharge path rather than becoming another route for contamination.

Air gap distance and backflow protection

Clause 7.4 requires the air gap distance to be measured from the lowest point of the air inlet orifice to the critical water level, with rules for single-supply and multiple-supply arrangements. It also addresses positive pressure backflow: the installation must position and protect the inlet so returning fluid cannot reach it.

Clause 7.5 gives the verification method for the air gap, and Clause 7.6 requires the air inlet orifice to pass the vacuum test in Annex A with no backflow. This is the main acceptance check for proving that the air gap still interrupts backflow under test conditions.

Marking and technical documents

Clause 8 requires each appliance, except site-constructed products, to be clearly and permanently marked and visible, with the manufacturer identification, family/type, denomination and standard reference. Clause 9 requires installation instructions that show how to keep the air gap effective, including against positive pressure backflow.

What terms does SIST EN 13078:2004 define?

SIST EN 13078:2004 uses a small set of terms to describe the geometry of the air gap and the water levels being checked.

• Air gap with submerged feed incorporating air inlet plus overflow, Family A, type C - a permanent vertical distance between the lowest point of the air inlet orifice and the critical water level at which the container overflows.
• Spillover level - the level at which the receiving vessel starts to overflow with all outlets closed.
• Critical water level - the liquid level reached 2 s after closing the water inlet, starting from the maximum fault level.
• Dimension h - the height between the spillover level and the critical level.
• Maximum level H - the highest water level reached above the spillover level under positive pressure fault conditions with all outlets closed.
• Splashing - a condition where splashing, foaming or turbulence can bring the liquid into contact with the air inlet orifice.
• Diameter of feed pipe (bore D) - the maximum internal diameter within the last metre of the supply pipe or the DN of the inlet connection.

Who uses SIST EN 13078:2004?

SIST EN 13078:2004 is used by manufacturers of backflow prevention devices, designers of water installations, installers and inspection or test laboratories. It is also relevant to quality managers and buyers who need to specify or verify air gaps for potable water protection in water supply systems and other drinking-water installations.

Which standards are used with SIST EN 13078:2004?

SIST EN 13078:2004 refers to EN 1717:2000 for the general protection framework for potable water installations and for the air break to drain requirement. It also refers to EN 837-1 for the vacuum gauges used in Annex A.

What does the SIST EN 13078:2004 document contain?

SIST EN 13078:2004 contains the design principle figure, the graphic symbol, the designation format, and the main construction and verification requirements for Family A, type C air gaps. Annex A gives the vacuum test setup, apparatus and procedure, and Table A.1 gives recommended vacuum vessel capacities for different bore sizes. The document is therefore a mix of specification, identification rules and test method, which supports design review, product verification and installation checking.