how to fix CL elevation for heat exchanger -----

Hi Karthik,

This information was taken from the training section of this website. pipingdesigners.com/Training.htm

Please take the time to read all these training articles, as they contain some very good information.

Exchangers, Shell and Tube
Shell and tube exchangers should be grouped together wherever possible. Stacked shell and tube exchangers should be limited to four shells high in similar service; however, the top exchanger should not exceed a centerline elevation of 18 feet (5.5m) above high point of finished surface, unless mounted in a structure. Keep channel end and shell covers clear of obstructions such as piping and structural members to allow unbolting of exchanger flanges, and removal of heads and tube bundles.
Exchangers with removable tube bundles should have maintenance clearance equal to the bundle length plus 5 feet (1.5m) measured from the tube sheet to allow for the tube bundle and the tube puller.
Maintenance space between flanges of exchangers or other equipment arranged in pairs should be 1'- 6" (0.5m) (min.). Exchanger maintenance space from a structural member or pipe should not be less than 1'- 0" (300mm) (min.).

Anton has given you good advice for the maximum height for the center line of the top unit of a stacked multiple shell exchanger.

Now, for the minimum height of a single shell or the bottom shell of a multiple-shell stacked unit.
Determine the following dimensions:

The nozzle projection of the largest bottom nozzle.
The gasket thickness
The height of the mating flange (Face of flange to the weld)
The center to end of the Elbow (1.5 times the nominal diameter)
Half the actual diameter of the pipe
The thickness of the Insulation
12" minimum clearance from the outside of the insulation to the high point of paving

Add these dimensions and round of the total up to the next reasonable even number.
Now deduct the Saddle height from this dimension and see what the top of grout will be for the pier
Consult with the Civil/Structural engineer and adjust the final center line to satisfy everyone.