Figure 3A Figure 3B Floating head tail pipe I.D. Internal bellow assembly Shell cover head Flange 1 - refer to Figure 3B Flange 2 - pad flange welded to head SPECIAL UPPER FLANGE 1 Inner gasket O.D. Gasket 3 Inner gasket I.D. Gasket 1 Flange 3 - refer to Figure 3C Gasket 2 GASKET 1 Middle gasket Middle gasket O.D. I.D. GASKET 2 Configuration 2 disadvantages: * Two manways located at 180 deg from each other are required in the shell cover at the Grayloc-clamp assembly location to facilitate the assembly and dismantling of the bellow assembly from shell cover * Because manways are required at the Grayloc clamp location, the shell cover, and the complete heat exchanger must be of longer length * The gasketed joints between the floating-head tailpipe and the bellow flange and those at the Grayloc clamps are not accessible from outside of the shell cover, so removal of the shell cover is necessary for gasket replacement Configuration 3 In this configuration, the floating-head tailpipe is welded with the expansion bellow assembly at one end (Figure 3A). The other end of the bellow assembly is welded to a non-standard flange (Flange 1). This special flange has two gaskets - both inside and outside of BCD and the bolting arrangement is not through-bolt type (Figure 3B). A pad flange (Flange 2) is welded to the shell cover head. The external piping spool or tube-side nozzle outside of the shell cover is bolted to the bellow tailpipe flange (Flange 1) and shell cover flange (Flange 2), with the help of another non-standard flange (Flange 3), which is welded to the pipingspool nozzle neck (Figure 3C). Again, Flange 3 is a special kind of flange. It has three gaskets and two set of bolts (BCD). Both set of bolts have not through-bolt-type arrangement. The inner set of bolts is used to connect Flange 1 with Inner bolts Outer bolts B.C.D. B.C.D. O.D. SPECIAL EXTERNAL FLANGE 3 two gaskets (the inner and outer gaskets). The outer set of bolts is used to bolt together the pad Flange 2 and the special Flange 3 with the gasket, inside of BCD. Flange 3 is exposed to both tube-side and shell-side fluids. The shell cover and bellow tailpipe CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM FEBRUARY 2017 FIGURE 3. In configuration 3 of the special flange joint, the floating-head tailpipe is welded to the expansion bellow assemby at one end Figure 3C Outer gasket Outer gasket O.D. I.D. GASKET 3 I.D. B.C.D. O.D. 51http://WWW.CHEMENGONLINE.COM