Standard exchangers with same mechanical design, materials, and use as EM type exchangers. According to international coding “BEW” means pull-out bundle with one fixed tubesheet, one floating tubesheet with two gaskets separated by a telltale ring to avoid mixing of the two fluids even with leaky or broken gaskets.
As for EM type exchangers the selection can be type “A” for low flowrate shellside, and type “B” for high flowrate shellside. The wide range of shellsize and tubelength makes this type of exchangers able to solve most problems even for high dutyratings.
The measure of Ef is valid only for: flat UNI,SO.ANSI & SAE flanges. For Welding neck type flanges, add 20 (mm) to Ef.
For the 8″ series drain & went of 1/2″ GAS is used.
For size 5+6 inch, feet are fixed into the cover screws and they are orientable on site. For the 8” inch size, feet are welded to the shellpipe with the same dimension
of EM type.
OnIy for the marine exchangers we provide two zink anodes, diam. 3/8″ GAS threaded, inspectionable for maintenance
Before unscrewing anything, pressure on both sides must be releived, while in EM type shellside not need to be releived. WE type exchanger have:
After taking off all gaskets the exchanger can be cleaned on tubeside only or also shellside by pulling the bundle out.
Once pulled the bundle out (taking special care or long bundles: once bent, the bundle is nearly impossible to fit it into the shellpipe again!) must take care not to damage tubes, baffles, avoid to scratch the surface of the floating tubesheet, otherwise the O ring will then leak.
It is a good practice to change gaskets (O rings) each time the bundle is removed. To tigthten bolts check parallelism inbetween rings and covers, tighten bolts diagonally!