We are happy to announce that our line of Speck pumps has just been expanded yet again. In the TOE-G and TOE-M series, we now have frame size 100-200. In addition, Speck is currently testing a 100-160, 100-250, and 125-200 frame sizes.
Speck has added what they feel are very important improvements in the pump casings for the new frame sizes: centre-lined suspension and double volute casing. The engineers at Speck believe that both features will greatly extend the pumps’ durability.
Double volute casing is more durable because it decreases the radial forces within the pump. According to Speck, the distribution of static pressure on the impeller is uneven, and it causes radial forces that can produce undue wear and tear on the sleeve bearings, and reduce their durability. This force increases in proportion to the size of the impeller. In other words, the larger the impeller, the greater the radial forces: this means more wear and tear is put on your pump.
To counteract excessive radial force, Speck is now using a double volute casing on their larger pumps. The casing has double spirals, which significantly reduce the amount of radial force, which causes less wear and tear on the radial and axial bearings. This, in turn, extends their durability.
Speck engineers have found through extensive testing that double volute casing is essential when operating a larger pump with a rotational speed of 3500 rpm or higher.
Speck has also found that when the heat transfer oil heats up to 350ºC, it causes the volute casing to expand. This expansion causes the pump shaft to bend and incline, pulling it in a different direction from the motor shaft, which remains parallel to the base plate. To make a long story short, the larger the volute casing, the more this heat expansion causes a problem.
To counteract this misalignment, Speck now uses centre-lined suspension for the volute casing. This removes all of the heat-related problems and fixes the misalignment caused by expansion. The new casings still correspond to the EN 733 standard for connection. Speck is the only company that currently offers centre-lined volute casing on their heat transfer pumps, and is in the process to converting all of their frame sizes to centre-lined suspension.