EN 1092-1 Flanges - PN10 And PN16 - Slip-On Plate Type 1

[JCarver]

EN 1092-1 PN10 and PN16 slip-on plate type flanges have identical dimensions up to and including size DN150. However, even though fabricated of the same material, their pressure/temperature ratings are different. For example, if fabricated from Material Group 3E0 (P245GH), PN10 flanges are rated for 10 bar at 50C and down to 5.9 bar at 400C, while PN 16 flanges are rated for 16 bar at 50C and down to 9.5 bar at 400C.

Are these PN10 and PN16 flanges actually identical? Would they be deemed interchangeable? Perhaps the ratings are simply provided as guidance for use of the same flange in different pressure applications.

Many Thanks for any advice.

 

[The Obturator]

You'll most probably find that manufacturers/suppliers of such flanges stamp all the applicable ratings on the one flange. They are physically the same in dimension. Rating is dependant on size and material at a given temperature. Its just the way the tables have been established and of course they differ with larger sizes.

Golden (and simple) rule: Make sure the flange is stamped with the appropriate rating for the intended application.

*** Per ISO-4126, the generic term 'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

 

[mk3223]

It's similar that, in the ASME B16.5, the CL400 flange is the same dimensions as the 600# for the sizes 1/2" to 3-1/2". So, these flanges can be used for either pressure ratings.

 

[JCarver]

Thank-you both.

I have seen flanges stamped with PN10 and others with PN16, and I am told that flanges stamped with PN10/PN16 exist. It is just interesting that such an overlap would be permitted. I would have thought that PN10 flanges would not be recognized/allowed where physically identical PN16 equivalents are available.

I wonder if the cost of PN10 and PN16 flanges of the same size and material are equivalent.

It is interesting that ASME B16.5 also has a similar overlap for class 400 and 600 flanges. Perhaps such overlap is a legacy issue associated with the evolution of the standard.

 

[The Obturator]

Quite. But common sense says you would not use a flange marked only with PN10 for a PN16 requirement, even if the dimensions were identical for that size. Say something went wrong and it was investigated.

*** Per ISO-4126, the generic term 'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

 

[LittleInch]

ASME 16.5 class 900 and 1500 flanges 2" and below are also identical.

Most people simply buy class 1500 flanges at that size even for a class 900 system to avoid any issues.

Occasionally people who don't realise think they are being overcharged when they get class 1500 stamped flanges when they only need class 900 without realising...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JCarver]

Many Thanks.

It is interesting that any overlap is permitted. You would think that the standard would not recognize class 900 flanges of size 2" and below so as to avoid confusion. Within this class and size range, the standard could simply indicate use of components of the next higher class. In this manner, class 900 flanges would only be available for flanges larger than 2".

I can understand how people might believe they were being overcharged if they ordered class 900 flanges and receive class 1500. I wonder how people who order class 1500 flanges and receive class 900 react. While the components are identical, fabricators would have to either return/exchange them or expend significant energy convincing customers that they are equivalents.

I appreciate all the help. Merry Christmas.

 

[LittleInch]

That's why you can't actually buy a class 900 2" flange in reality. Even if you ask for one they just send you one stamped class 1500...


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.