Shell and Tube Heat Exchanger Manufacturer in Sudan

Different Types of TEMA Classes for Shell and Tube Heat Exchangers

The Tubular Exchanger Manufacturers Association (TEMA) classifies shell and tube heat exchangers into three main designations based on service conditions, mechanical robustness, and industry requirements:

1. TEMA Class R – Refinery & Severe Service

Applications:

• Oil refineries, petrochemical plants, high-pressure/high-temperature (HPHT) services.
• Harsh environments (corrosive fluids, fouling, thermal cycling).

Key Features:
Heavy-duty construction (thicker shells, reinforced tube sheets).
Strict tolerances for leakage prevention.
Removable bundle designs (for easy cleaning/maintenance).
High-pressure ratings (ASME Div 1 or Div 2 compliance).

Common Configurations:

• AES (Front-end stationary head, single-pass shell, rear-end floating head).
• BEM (Bonnet-type front head, fixed tube sheet, single-pass shell).

2. TEMA Class C – Commercial & General Service

Applications:

• HVAC, power plants, food processing, light chemical industries.
• Moderate pressure/temperature, non-corrosive fluids.

Key Features:
Cost-effective (lighter construction than Class R).
Simpler fabrication (fewer stringent requirements).
Fixed or floating tube sheet designs.

Common Configurations:

• NEN (Channel-type front head, fixed tube sheet, single-pass shell).
• AEP (Front-end stationary head, single-pass shell, rear-end packed floating head).

3. TEMA Class B – Chemical Process Service

Applications:

• Chemical processing, pharmaceuticals, aggressive media (acids, solvents).
• High corrosion risk, frequent thermal cycling.

Key Features:
Balanced between Class R & C (better corrosion resistance than Class C).
More stringent than Class C but not as heavy as Class R.
Often uses exotic materials (titanium, Hastelloy, duplex SS).

Common Configurations:

• BKU (Bonnet-type front head, U-tube bundle, single-pass shell).
• AEW (Front-end stationary head, floating head with backing device).

Comparison Table: TEMA Classes R, C, and B

Parameter	TEMA Class R	TEMA Class C	TEMA Class B
Service Conditions	Severe (HPHT, fouling)	Moderate (general-purpose)	Corrosive/cyclic
Construction Cost	Highest	Lowest	Medium
Maintenance	Removable bundles common	Fixed tube sheets common	Depends on design
Typical Industries	Oil & gas, refineries	HVAC, power plants	Chemical, pharma
Example Configs	AES, BEM	NEN, AEP	BKU, AEW

TEMA Nomenclature Breakdown (Example: AES, BEM, NEN, etc.)

1. First Letter → Front Head Type
   1. A: Channel with removable cover (most common).
   1. B: Bonnet (integral cover, lower cost).
   1. N: Channel integral with tube sheet.
2. Second Letter → Shell Type
   1. E: Single-pass shell.
   1. F: Two-pass shell.
   1. G: Split flow (for horizontal thermosiphon reboilers).
3. Third Letter → Rear Head Type
   1. S: Floating head (removable bundle).
   1. T: Fixed tube sheet.
   1. U: U-tube design.

Example:

• AES = Removable front channel (A) + single-pass shell (E) + floating head (S).
• BEM = Bonnet front head (B) + single-pass shell (E) + fixed tube sheet (M).

When to Use Which TEMA Class?

• Class R → Refineries, high-pressure steam, fouling fluids.
• Class C → Low-cost HVAC, water cooling, non-corrosive duties.

Class B → Chemical plants, corrosive/thermal cycling services.