Welding of stainless steel refractory anchors to 1 1/4Cr-1/2Mo shell

[litstatic]

Regarding the subject, is there an alternative refractory lining support? Since the API RP 934-C requirements below are impractical if applied to refractory anchors.

We have a reactor in Hydrogen Service with the following info:

Equipment Name: PreReformer
Design Pressure: 50 bar
Design Temp: 235°C
(Operating Temp): 515°C
Refractory Lining thickness: 75 mm (castable)
Material: SA-387 Gr.11 Cl.2
MDMT: -19°C
Inside Diameter: 4150 mm
TL to TL: 3300 mm

My concerns are the following:

1. Welding of stainless steel refractory anchors to 1 1/4Cr-1/2Mo shell -- dissimilar metal weld.

2. Para. 7.1.2 a) of API RP 934-C requires that "All welded joints including non-pressure attachments to the vessel body should have full penetration joint design." -- impractical since refractory anchors are small and of wire material.

3. What NDE method to be used after welding of refractory anchors?

4. Para. 7.3.1 of API RP 934-C: All base metals should be heated to a minimum of 300 °F (150 °C) during all welding, rolling, thermal cutting, and gouging operations. -- w/c is also impractical since the entire internal surface of the reactor is refractory lined.

Thanks in advance.

 

[metengr]

1. Welding of stainless steel refractory anchors to 1 1/4Cr-1/2Mo shell -- dissimilar metal weld.

This is not uncommon using 409 stainless steel studs.

2. Para. 7.1.2 a) of API RP 934-C requires that "All welded joints including non-pressure attachments to the vessel body should have full penetration joint design." -- impractical since refractory anchors are small and of wire material.

Not exactly, these would be non-load bearing.

3. What NDE method to be used after welding of refractory anchors?

Visual to check for flash and a rake test.

4. Para. 7.3.1 of API RP 934-C: All base metals should be heated to a minimum of 300 °F (150 °C) during all welding, rolling, thermal cutting, and gouging operations. -- w/c is also impractical since the entire internal surface of the reactor is refractory lined.

Again, this may not apply for non-load bearing studs or anchors.