BS EN 13445 Query

[John.I]

Hi,

I have a query with respect to Fastener grades/standards that comply with BS EN 13445-2.

There is a requirement to use 1.4501 Super Duplex Stainless Steel Fasteners to BS EN 10088. This standard is not listed anywhere in the code under 'fasteners', it is however a harmonized product standard. Can anyone confirm whether this grade can be used without undertaking a Particular Material Appraisal.

Many thanks

 

[MGZmechanical]

Yo can look at
EN 1515-4 Flanges and their joints. Bolting. Selection of bolting for equipment subject to the Pressure Equipment Directive 97/23/EC

In that list you have 1.4980, 1.4923, 1.4986.
Not sure if 1.4501 is listed somewhere.

Best regards

 

[XL83NL]

I hate dislike the EN standards on this part. They require much more extensive reading, going back and fourth through the codes and its various subsections and other standards, and in the end sometimes leave you with no answer (in contrast to ASME). Anyway, here's a shot.

BS EN 10088 is most probably not the standard acc. which your bolts have been made. BS EN 1008 is for Stainless steels. Technical delivery conditions for sheet/plate and strip of corrosion resisting steels for general purposes. You have bought a duplex piece of bar (which is conform a certain standard, say A) which is then machined to a bolt acc a different standard, say B.

Some of the listed product form standards for bolts in EN 13445-2 are;
- EN ISO 898 Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws and studs with specified property classes — Coarse thread and fine pitch thread (ISO 898-1:2013)
- EN ISO 3506 Mechanical properties of corrosion-resistant stainless-steel fasteners — Part 1: Bolts, screws and studs (ISO 3506- 1:2009)

I dont see any (immediate) reason why you couldnt use 1.4501. What makes you believe that "it is however a harmonized product standard"? Furthermore Im not sure if a PMA is required, since bolting is usually not regarded as a main pressure bearing part (by most people, however some think the opposite - this is what makes bolting so challenging in the PED!).

 

[John.I]

Thanks for the info chaps.

Unfortunately 1.4501 is not listed in EN 1515-4.

BS EN 3506 does not include 1.4501 however it does mention that Duplex Stainless Steels will be included in a future edition of the standard (last published in 2009).

Would it be satisfactory if the Fasteners were manufactured from 1.4501 to BS EN 10272 'Stainless Steel Round Bar for Pressure Purposes'? My only concern is that the design code does not list this spec in the fasteners section, although it does include it in the round bar category.

 

[XL83NL]

Yes, Ithink so, provided you meet the requirements for nuts and type of thread. See EN 1515-series for this matter.