Applications: Used in kitchen

Materials Used: o
equipment, food processing,
chemical containers, automotive
a. Common Materials: parts, and architectural trim.
 Key Characteristics:
 Stainless Steel (e.g., 304, 316): Offers o Also known as 18/8 stainless steel
good corrosion resistance and strength, due to its 18% chromium and 8%
commonly used in various chemical nickel content.
processes. o Non-magnetic in the annealed
 Carbon Steel: Used in applications where condition but may become slightly
corrosion resistance is less critical, but it magnetic after cold working.
may need coating or linings for enhanced
durability.
2. Stainless Steel 316:
 Nickel Alloys (e.g., Inconel, Monel):
Used for highly corrosive environments
 Composition:
due to their excellent corrosion resistance.
o Chromium: 16-18%
 Copper and Copper Alloys: Sometimes
o Nickel: 10-14%
used for their excellent thermal
o Molybdenum: 2-3%
conductivity, though less common in
o Carbon: ≤ 0.08%
petrochemical applications due to
corrosion issues. o Manganese: ≤ 2%
o Other elements: Silicon,
b. Considerations for Material Selection: phosphorus, sulfur
 Properties:
 Corrosiveness of Fluids: Materials must o Corrosion Resistance: Superior to
resist corrosion from the process fluids. 304, particularly in chloride
 Temperature and Pressure Conditions: environments due to the presence
Materials must withstand the operational of molybdenum. More resistant to
temperature and pressure. pitting and crevice corrosion.
 Cost and Availability: Balancing material o Strength: Similar to 304 but with
cost with performance requirements. enhanced strength at elevated
temperatures.
o Formability: Maintains good
1. Stainless Steel 304:
formability and weldability.
o Applications: Used in marine
 Composition:
o Chromium: 18-20% environments, chemical
o Nickel: 8-10.5%
processing, medical implants,
o Carbon: ≤ 0.08%
pharmaceutical equipment, and
food preparation equipment.
o Manganese: ≤ 2%
 Key Characteristics:
o Other elements: Silicon,
o Known as marine-grade stainless
phosphorus, sulfur
steel due to its enhanced corrosion
 Properties:
resistance.
o Corrosion Resistance: Offers
o More expensive than 304 stainless
excellent corrosion resistance in a
steel due to the addition of
wide range of environments,
molybdenum.
including those with acids and
chloride solutions. However, it is
susceptible to chloride-induced 3. Inconel:
stress corrosion cracking.
o Strength: Good mechanical  Composition:
properties with high tensile o Nickel: 50-70%
strength. o Chromium: 14-23%
o Formability: Easily welded and o Iron: Remainder, with small
formed, making it one of the most amounts of molybdenum, niobium,
commonly used stainless steels.
 cobalt, and titanium in various o Monel alloys are expensive due to
grades. their high nickel content.
 Properties: o Common grades include Monel
o High-Temperature Resistance: 400 and Monel K-500, with the
Maintains strength and oxidation latter having higher strength due to
resistance at extremely high the addition of aluminum and
temperatures, making it ideal for titanium.
use in extreme environments.
o Corrosion Resistance: Excellent Comparison Summary:
resistance to oxidation,
carburization, and other forms of  Stainless Steel 304 vs. 316:
corrosion at high temperatures. o 304: More common, cheaper, good
o Strength: High tensile and creep- general corrosion resistance.
rupture strength at elevated o 316: Better corrosion resistance,
temperatures. especially in marine and chloride
o Applications: Used in aerospace, environments, due to molybdenum.
gas turbines, nuclear reactors, and  Inconel vs. Monel:
chemical processing plants. o Inconel: Best suited for high-
 Key Characteristics: temperature and extreme
o Inconel alloys are difficult to environments with excellent
machine and weld due to their oxidation resistance.
hardness. o Monel: Superior corrosion
o Common grades include Inconel resistance in highly corrosive
600, 625, 718, each with specific environments, especially in marine
properties for different and chemical applications.
applications.
Industry Standards:
4. Monel:
 ASME (American Society of
 Composition:
o Nickel: 63-70%
Mechanical Engineers): Standards
o Copper: 20-29% for design, materials, and testing.
o Iron: 2-3%  API (American Petroleum
o Manganese: 1-2% Institute): Standards specifically for
o Other elements: Small amounts of the petroleum industry.
silicon, carbon, and sulfur.  TEMA (Tubular Exchanger
 Properties: Manufacturers Association):
o Corrosion Resistance:
Standards for shell and tube heat
Exceptional resistance to corrosion
in a wide range of environments, exchangers.
particularly in seawater,
hydrofluoric acid, and sulfuric HK-30:
acid.
o Strength: High strength and Typically a type of high-alloy stainless
toughness across a wide steel.
temperature range.
o Magnetic Properties: Non-  Chromium (Cr): Approximately 24-
magnetic, making it suitable for 27%
use in magnetic-sensitive  Nickel (Ni): Approximately 12-15%
applications.  Molybdenum (Mo): Approximately 2-
o Applications: Used in marine 3%
engineering, chemical processing,  Iron (Fe): Balance
heat exchangers, and valves.
 Key Characteristics:
 Corrosion Resistance: Excellent resistance to  HK-30 and HK-40 are high-alloy stainless
oxidation, sulfuric acid, and chlorides, making it steels used in demanding petrochemical and
suitable for harsh chemical environments. chemical processing environments.
 Temperature Resistance: Good performance  HK-30 is known for its excellent resistance to
at high temperatures, typically up to around 800- corrosion and high temperatures, while HK-40
900°C. offers even higher corrosion resistance and is
suited for extremely harsh conditions.
 Mechanical Strength: High tensile strength  Both materials are used in applications
and toughness, even at elevated temperatures. requiring durability and resistance to chemical
attack, such as heat exchangers, reactors, and
high-pressure piping systems.
Petrochemical Processing: Used in
equipment exposed to corrosive chemicals Choosing between HK-30 and HK-40 would
and high temperatures, such as reactors, depend on the specific requirements of the
heat exchangers, and piping. application, such as the nature of the chemicals
being processed, operating temperatures, and
HK-40: mechanical stress conditions.
 Alloy: Another high-alloy stainless steel grade,
but with a slightly different composition Austenitic Stainless Steels
compared to HK-30.
 Main Elements: Typically contains chromium **a. Grade 304 (1.4301 / UNS S30400):
(Cr), nickel (Ni), and molybdenum (Mo), tailored
for specific corrosion resistance and mechanical 18% chromium (Cr), 8% nickel (Ni).
properties.
 Typical Composition: **b. Grade 316 (1.4401 / UNS S31600):

 Chromium (Cr): Approximately 24-30% Approximately 16% chromium (Cr), 10% nickel
 Nickel (Ni): Approximately 14-20% (Ni), 2% molybdenum (Mo).
 Molybdenum (Mo): Approximately 2-4%
 Iron (Fe): Balance **c. Grade 321 (1.4541 / UNS S32100):

Properties: Similar to 304 but with titanium (Ti) added (around

0.5%).
 Corrosion Resistance: Very high
resistance to a wide range of corrosive 2. Ferritic Stainless Steels
environments, including chloride-induced
pitting and crevice corrosion. **a. Grade 430 (1.4016 / UNS S43000):
 Temperature Resistance: Performs well
in high-temperature environments, often **b. Grade 446 (1.4762 / UNS S44600):
up to around 900°C.
 Mechanical Strength: High strength and 3. Martensitic Stainless Steels
good ductility at elevated temperatures.
**a. Grade 410 (1.4006 / UNS S41000):
Applications: Approximately 11.5-13.5% chromium (Cr).
 Petrochemical Industry: Used in **b. Grade 420 (1.4021 / UNS S42000):Approximately
applications similar to HK-30, including 12-14% chromium (Cr).
high-temperature and corrosive
environments. Suitable for parts exposed 4. Duplex Stainless Steels
to severe chemical conditions, like heat
exchangers, pressure vessels, and
**a. Grade 2205 (1.4462 / UNS S32205):
pipelines.
Approximately 22% chromium (Cr), 5% nickel
(Ni), 3% molybdenum (Mo).
Summary:
**b. Grade 2507 (1.4410 / UNS S32750): (Ni), 4% molybdenum (Mo).
Approximately 25% chromium (Cr), 7% nickel

5. Precipitation-Hardening Stainless Steels

**a. Grade 17-4 PH (1.4542 / UNS S17400):

Approximately 15-17% chromium (Cr), 3-5% nickel (Ni), with additional elements like copper (Cu) for hardening.

**b. Grade 15-5 PH (1.4545 / UNS S15500): Similar to 17-4 PH but with slightly different compositions and
properties.

Summary:

 Austenitic Stainless Steels: Excellent corrosion resistance and good formability, used in a wide range of
applications.
 Ferritic Stainless Steels: Good corrosion resistance, especially in mildly corrosive environments, and cost-
effective.
 Martensitic Stainless Steels: High hardness and wear resistance, but with lower corrosion resistance.
 Duplex Stainless Steels: High strength and excellent corrosion resistance, suitable for aggressive
environments.
 Precipitation-Hardening Stainless Steels: High strength and hardness, used in demanding applications.

Shell SS316 Diameter: 500mm, Length: 2000mm, Thickness: 10mm 1

Tubes SS316L Diameter: 25mm, Length: 1500mm, Wall Thickness: 2mm 200
Tube Sheets SS316 Thickness: 30mm, Diameter: 500mm, Hole Size: 25mm 2
Tube Sheet Gaskets Graphite Thickness: 5mm, Diameter: 500mm 2
Baffles SS316 Size: 200mm x 200mm, Spacing: 150mm 10
End Caps / Heads SS316 Flanged, Diameter: 500mm 2
Nozzles SS316 Size: 50mm, Type: Flanged 4
As
Support Hardware Carbon Steel Brackets, Bolts required
Heat Transfer
Enhancement Materials Finned Tubes Diameter: 25mm, Length: 1500mm 50
SS316 or As
Instrumentation Alloy Temperature Sensors, Pressure Gauges required
Stainless As
Cleaning Tools Steel Brushes, Cleaning Agents required
As
Seals and O-Ring Viton or PTFE Size and type as per design required

Material Costs , Manufacturing Costs, Assembly Costs, Other Costs [ Transportation, Installation, Contingency (10%)
of total Cost of HE]
Example Dimensions for a Shell and Tube Heat Exchanger

a. Shell Diameter: 1.5 meters d. Number of Tubes: 500 f. Baffle Spacing: 0.75 meters

b. Tube Bundle Length: 4 meters e. Tube Sheet Diameter: 1.5 g. Nozzle Sizes: 100 mm
meters
c. Tube Diameter: 25 mm

Effectiveness
Definition:
Effectiveness measures how well a system, process, or component achieves its intended purpose or goal. It
is about doing the right thing and producing the desired outcome.

Context in Engineering:

 In a heat exchanger, effectiveness (ε) is a measure of how well it transfers heat between two fluids
compared to the maximum possible heat transfer.
 It is calculated as the ratio of the actual heat transfer to the maximum possible heat transfer:

 High Effectiveness: Indicates that the heat exchanger is operating close to its theoretical maximum
potential.

 Low Effectiveness: Suggests that the system is not performing as well as it could be.

Efficiency

Definition:
Efficiency measures the output of a system relative to its input. It is about doing things in the right way,
minimizing waste, and maximizing output from the resources used.

Context in Engineering:

 In general, efficiency is calculated as:

 For a heat exchanger, thermal efficiency might refer to how well the system converts the heat input
into useful heat output, minimizing losses.
 High Efficiency: Indicates that the system is effectively using its input energy, with minimal losses.
 Low Efficiency: Implies significant losses, indicating room for improvement.

Key Differences:
 Effectiveness focuses on achieving the desired outcome or goal, regardless of the resources used. It
answers the question, "Are we doing the right thing?"
 Efficiency focuses on minimizing the resources used to achieve the desired outcome. It answers the
question, "Are we doing things