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How To calculate elongation/prevent warping of high temperature 304SS solder pot

I am using 600 L x 200 H x 380 w and 2.5 thickness (MM) ss304 soldering tank. plate heaters are mounted on side wall externally. I am using it last 5 days at 250 deg C temp without problem but now when I heated it at 280 °C the tank get elongated / bent. how can I calculate elongation/bending. how can I avoid it?

Seema ahuja
subcontractor - Pune, India
January 6, 2011

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The amount of growth of 304 is 17.3 ^-6 times the original length times the temperature difference (form cool to hot).

The tank should grow uniformly since it is the same metal. Since it is not, there has to be a difference in temperature from one point to another point on your tank. Best guess is some part is cooler because of a flange or some part is hotter because of the asymmetrical heat application. Best guess is it is a combination of both and it shows up as a warped tank at the higher temperature because of greater temp differences in the tank.

James Watts
- Navarre, Florida
First of two simultaneous responses -- January 11, 2011

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It's not simple for the uninitiated to calculate stresses and deflections, but probably the simplest calculations that are relevant to steel (or SS) tanks can be found in the small section in Megyesy's Pressure Vessel Handbook (14th Edition) dealing with atmospheric rectangular tanks. Good Luck.

Jon Barrows, MSF, EHSSC
GOAD Company

Independence, Missouri

Second of two simultaneous responses -- January 11, 2011

I have a solder bath of 330 kg capacity. to melt solder I am going to use plate heaters on four sides . tank thickness is 4 mm , material 304 ss , dimensions : 650 mm length , 180 mm height and 305 mm width. how can I select wattage of heaters?

Ashutosh Bhagwat
buyer - Pune, India
May 30, 2011