BEM TEMA Style Shell and Tube Heat Exchangers

BEM-style shell and tube heat exchangers are one of the most commonly used configurations in industrial and HVAC heat transfer pplications due to their simplicity and cost-effectiveness. They feature tube sheets that are fixed in place via welding to the shell, a straight tube bundle, and a removable bonnet on the stationary end, allowing for mechanical access to the tubes for maintenance or inspection. On the other hand, the shell side can only be accessed chemically without full removal and disassembly of the unit, meaning that shell-side fluids tend to be selected based on being clean (non-fouling) when possible; common examples include steam, cooling water, or light hydrocarbons. The fixed tube sheets offer a robust and pressure-tight seal, though the design does not accommodate differential thermal expansion as well as floating-head or U-tube configurations.

Valutech offers shell and tube heat exchangers in the BEM configuration from our industry-leading manufacturing partners who are able to work with a diverse range of construction materials to provide off-the-shelf and custom-fabricated units adhering to strict manufacturing standards. We also offer spare gaskets (girth flange and bonnet gaskets) for all of our shell and tube heat exchanger models — for more information on our shell and tube manufacturing and spare part capabilities, please click here.

The ‘B’ front head denotes a bonnet-style integral cover; it is the most cost-effective front header option in terms of capital nvestment, and is well suited to high-pressure applications as it requires only a single seal. The ‘M’ style of cover is simply the rear head equivalent of the ‘B’ front head; however, mechanical access to the tube bundle requires disconnecting the piping. While fixed tube bundle constructions are more economical to build, they necessitate chemical cleaning of the tubes since they cannot be mechanically accessed, and they are not inherently suitable for high-temperature or high-pressure duties where thermal expansion is a concern. In order to accommodate for this, expansion joints (e.g. a bellows-style joint) can be specified, allowing the shell itself to expand and contract under thermal stress. While the ‘E’ style shell is limited to a single shell pass, the BEM configuration allows for a flexible number of tube passes using pass partitions, meaning that the thermal length of the unit can be expanded for a given set of physical dimensions.

The shell side of BEM units is not meant to be accessed regularly, making cleaner (non-scaling and non-corrosive) fluids suitable to this side of the unit; on the other hand, this means these units are suited to simple applications with minimal maintenance over the lifespan of the unit. The following applications are typical for BEM-style shell and tube heat exchangers: Chillers and condensers in HVAC applications with typical for BEM-style shell and tube heat exchangers:

• Chillers and condensers in HVAC applications with minimal thermal cycling.
• Oil cooling in hydraulic systems using clean, closed-loop oil circuits.
• Process fluid heating and cooling using clean shell-side fluids with minimal thermal stress, such as in water treatment and chemical dosing systems.
• Heating and cooling of process water in general manufacturing and utility applications.
• Non-corrosive, thermally stable duties in food and beverage plants such as thermal tempering of wort in breweries and heating of pasteurizer return-water in dairies.

As mentioned above, the BEM configuration is a versatile style of shell and tube heat exchanger suited for a wide variety of general applications; however, it is generally optimal in clean and stable systems where fouling is a limited concern. Their fixed tube sheets mean there are minimal gaskets to maintain and the tube side can handle high-pressure duties due to welding on both sides.