What are the difference between Sanitary Welded and Seamless Tubes.
Sanitary Seamless Tube manufacturing process
Sanitary Seamless Tubes are produced by the rolling or rotary piecing method.
A stainless rod is heated and pierced while rollers will size the OD of the tube.
The end result is a tube with no seams.
Sanitary Welded Tube manufacturing process
Sanitary Welded Tubes production starts with a stainless steel coil being rolled to achieve a desired wall thickness. The coil is then cut into sizes depending on the tube OD. The cut coil then goes through rolling operations and the seam is welded. Finally the tube is heat treated.
The main differences
In smaller sizes, seamless tubes many years ago used to have better internal surface polishing, because of the roughness of the welding bead. Because of improved manufacturing techniques of welded tubes, today there is little to no difference in terms of surface roughness between Sanitary Welded and Seamless Tubes.
Many years back, seamless tubes used to be superior in terms of corrosion resistance because of the welding seams. But because of improvements in the welding and forging of welded tube processes today, the difference is negligible. Today, only in the most extreme conditions in the electronic and semi conductor industry, corrosion resistance of welded tubes could be a problem. But in the food, beverage, and pharmaceutical industry, the corrosion resistance of welded tubes are really more than enough.
Due to the decreasing demand and rising prices, manufacturers today rarely produce Sanitary Seamless Tubes with sizes above 1". This means it is almost impossible to find ready stock of seamless tubes above 1".
If you use seamless tubes, you will also need seamless fittings. Seamless Fittings are almost non existent for sizes above 0.5", meaning you will probably have to mix seamless tubes with welded fittings in your system.
Finally, Seamless Tubes are priced much higher because of costly production processes and small production quantities.
Even High Purity Pharmaceutical BPE fittings and tubes today are mostly welded.
NKE Flow is a supplier of Hygienic Tubes. To see more specifications of our Sanitary Tubes, click the image link below.
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