Welding tube SA 213 T22 with tube S

[ritsa p]

Welding tube SA 213 T22 with tube SA 213 T22 WITH DIMENSIONS 44.3X7.8 mm, according to ASME min. preheat is 150 celsius. My question is
preheat should be done with propane or with heating media in order to maintained?

 

[Dhurjati Sen]

Electric so that proper record could be maintained in the form of pre-heat chart.
Propane (referring to gas torch maybe and usong temperature chalks) is less accurate and you cannot have any record.

DHURJATI SEN
Kolkata, India

 

[weldstan]

We used torch preheating with this grade of tubes nearly 100% of the time. Different story for T91 tubes.