SIST EN 3270:2004

SIST EN 3270:2004 is the Slovenian standard for blanking plugs with lockring for 8°30' pipe couplings in titanium alloy, issued by SIST on the basis of EN 3270:2001. It specifies the characteristics needed for aerospace applications, including dimensions, materials, surface treatment, marking and designation. Engineers, manufacturers, inspectors and buyers use it to specify and check compatible parts for aerospace fluid system connections.

What does SIST EN 3270:2004 specify?

SIST EN 3270:2004 specifies blanking plugs with lockring for pipe couplings 8°30' in titanium alloy, intended for aerospace use. It covers parts up to a nominal pressure of 28 000 kPa and a temperature range from -55 °C to +135 °C.

The standard is organized into six clauses: scope, normative references, required characteristics, designation, marking and technical specification. Clause 3 is the main technical part, because it ties the plug geometry, materials and surface treatment to the referenced figures, table and external standards.

What are the key requirements of SIST EN 3270:2004?

SIST EN 3270:2004 sets out the plug's configuration, materials, surface condition, identification and related technical basis. In practice, it tells the manufacturer what to make, what references to follow and how the finished part is to be identified.

Geometry and dimensions

Clause 3.1 says the configuration, dimensions and mass are given by Figure 1 and Table 1, and that dimensions apply before lubricating or anodizing. This matters because the part has to fit the matching coupling correctly before any coating changes its final size.

Table 1 links each code to the thread designation, associated dimensions, mass and lockring reference. For the reader, this is the ordering and drawing reference for selecting the correct size.

Surface condition

Clause 3.2 states that surface roughness follows Figure 1 unless the design documentation says otherwise. That gives the designer or supplier a defined finish to meet when the drawing does not override it.

Materials

Clause 3.3 requires the blanking plug material to comply with EN 3311 or EN 3314. This means the plug must be made from one of the specified titanium alloy bar materials suitable for machining.

Surface treatments

Clause 3.4 gives two approved surface-treatment routes. One is lubrication according to EN 2491 on all surfaces, after abrasive blasting with non-metallic grit, with a film thickness in the stated range. The other is anodizing according to AMS 2488D, type 2. In practice, this gives the supplier a controlled choice of finish, depending on the build specification.

Designation

Clause 4 gives the ordering designation format: a description block, the standard reference and the code from Table 1, with code I9005 inserted if needed. This matters for procurement because it fixes how the part is named on documents and purchase orders.

Marking

Clause 5 requires marking according to EN 2424, style A, and Figure 1. That tells production and inspection teams how the part is to be identified on the component itself.

Technical specification

Clause 6 points to EN 3079, type II. This links the blanking plug to the technical specification for the related pipe coupling family, so users know which broader coupling requirements apply.

What terms does SIST EN 3270:2004 define?

• Blanking plug - A threaded plug used to close the coupling opening and protect the port.
• Lockring - The ring used with the plug to secure the connection in service.
• Pipe coupling 8°30' - The aerospace coupling geometry addressed by this standard.
• MJ threads - The thread form used for the plug sizes listed in the standard.
• Port end - The coupling-side end, whose dimensions are referenced to EN 2603.
• Style A - The marking style required by EN 2424 for these parts.
• Type II - The technical specification category referenced from EN 3079.

Who uses SIST EN 3270:2004?

SIST EN 3270:2004 is used by aerospace manufacturers, machining suppliers, quality control teams and buyers who specify titanium alloy pipe-coupling parts. It is also useful for inspectors and engineers who need to verify dimensions, materials, surface treatment, marking and part designation for blanking plugs with lockring.

What changed in SIST EN 3270:2004 from the previous edition?

SIST EN 3270:2004 is identical to EN 3270:2001.

Which standards are used with SIST EN 3270:2004?

SIST EN 3270:2004 relies on several companion standards:

• ISO 5855-3 - limit dimensions for MJ threads for fluid-system fittings.
• EN 2424 - marking of aerospace products.
• EN 2491 - coating methods for molybdenum disulphide dry lubricants.
• EN 2602 - dimensions for ports for straight metric-size unions with locking ring.
• EN 2603 - dimensions for the port end of straight metric-size unions with locking ring.
• EN 2645 - dimensions for the locking ring.
• EN 3079 - technical specification for the related 8°30' pipe coupling adaptors.
• EN 3311 and EN 3314 - titanium alloy bar materials for machining.
• AMS 2488D - anodic treatment for titanium and titanium alloys.

What does the SIST EN 3270:2004 document contain?

The document contains a figure for the plug configuration and a table that ties each code to the corresponding thread, dimensions, mass and lockring reference. It also provides an example designation to show how the part is identified for ordering.

Clause 3 is the main technical section, because it combines geometry, roughness, materials and surface treatment. Clause 4 supports procurement and part identification, while Clause 5 supports product marking and Clause 6 links the plug to the broader coupling technical specification.