Do you know the difference between 'Type A' and 'Type B' buttweld fittings?

Do you know the difference between 'Type A' and 'Type B' buttweld fittings?

Did you know that we supply buttweld fittings according to EN10253-2 in both Type A and Type B? Maybe you did, but you may not have heard of it. We would like to explain briefly what the difference is.

Type A vs. Type B

Type A buttweld fittings have a limited utilisation factor, while Type B buttweld fittings are suitable for use at full utilisation.

Type A vs. Type BType A vs. Type B

*Image for illustration

"I regularly receive requests for Elbows or Equal Tees in Type B, but when I ask the customer whether this is really necessary, they often do not know exactly what it entails. If I then explain the difference, Type A is sometimes sufficient." 
Vincent Waanders, Accountmanager

We are happy to explain this to you on the basis of a practical example:

For example, if you have a DN100 PN16 (maximum operating pressure 16 Bar *) pipe system and you want to load it up to 12 Bar (= 75% of PN16 / 16Bar *), then the fittings in that pipe system should be able to handle 75% of the pressure factor. Type A fittings, however, have a limited utilization rate.
* medium = water; temperature = 20°C (for other temperatures and mediums there are conversion tables for the maximum load capacity)

As you can see in the table below, a 114.3 x 3.6 Elbow 90° EN10253-2 according to Type A can withstand 77% of the maximum working pressure, but a 114.3 x 3.6 Equal Tee EN10253-2 according to Type A only up to 34% and therefore not suitable for 12 Bar. In this case you could opt for a Type A welding elbow and a T-piece according to Type B.



Maximum utilization rate

114.3 x 3.6 Elbow 90° EN10253-2 3D





114.3 x 3.6 Equal Tee EN10253-2





According to DIN EN 10253-2: 2008-09
(This example is fictitious and no rights can be derived from it)

PN = Pressure Nominal

'Pressure Nominal' or the nominal pressure describes the maximum internal pressure that the pipe and the pipe components can handle, expressed in Bars. The nominal pressure only describes the working pressure in Bar when water flows through it at a maximum temperature of 20°C. When the temperature increases, the maximum load capacity will decrease depending on the specific properties of the medium.