Duplex (UNS S31803) welding fittings for ASME Section VIII, Div. 2 Service

[engrdon]

We have a Sect VIII, Div 2. vessel that requires S31803 duplex material for the fittings (elbows, reducers). Our supplier wants to provide SA-815 for Div. 2 service. We have scoured the Code, Interpretations, and Code Cases for any hint that SA-815 material is permitted in Div. 2 construction but found none; it is only acceptable for Div. 1.

1. Is there a reason that SA-815 (S31803) material is not allowed for Div. 2 service? And more importantly,

2. Is there any S31803 material for fittings that can be used in Div. 2 service? We have also searched for this but found nothing.

Need some insight.

 

[pradipgoswami]

Hi Engr Don,

You may please enquire with your supplier regarding SA 182 F51 forged fitting. Table -5A of ASME Sec II/D has allowable stress values for this grade in Sec VIII, DIV 2 service. However you may have to see all other details also as per SecVIII, DIV-2, before making final selction.

Regards,



Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario, Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299