Vapour Pressure of Water – Marcet Boiler Apparatus

The Vapour Pressure of Water – Marcet Boiler Apparatus is a laboratory experimental setup designed to demonstrate the fundamental thermodynamic relationship between the pressure and temperature of saturated water and steam.

Manufactured by Micro Technologies, the apparatus provides a practical method for recording the vapour-pressure curve of water and observing how saturation pressure increases as water temperature rises in a closed system.

The main experimental section consists of a robust stainless steel pressure vessel containing water. An electrical heating arrangement supplies controlled thermal energy to the water. As the temperature increases, water begins to evaporate and the pressure of the generated vapour rises.

Temperature and pressure are measured simultaneously during the experiment. The recorded values can be plotted to obtain the vapour pressure-temperature curve of water and compared with standard saturated steam data.

The Marcet Boiler experiment is particularly useful for demonstrating that, under saturated conditions, pressure and temperature are dependent thermodynamic properties. For a pure substance existing in liquid-vapour equilibrium, a particular saturation pressure corresponds to a particular saturation temperature.

The apparatus incorporates a pressure measuring instrument, temperature measurement arrangement, valves, piping, heating controls, and an electrical control unit. Its compact bench-mounted construction provides convenient operation in thermodynamics and thermal engineering laboratories.

Scope of Learning

The apparatus enables students to study:

• Vapour pressure of water
• Saturation pressure
• Saturation temperature
• Pressure-temperature relationship
• Liquid-vapour equilibrium
• Formation of saturated steam
• Vapour-pressure curve of water
• Thermodynamic properties of water
• Pressure measurement
• Temperature measurement
• Closed-system heating
• Steam properties
• Phase-change behaviour

Working Principle

A measured quantity of water is placed inside the closed pressure vessel and heated using the electrical heating system.

As the water temperature increases, evaporation occurs and vapour accumulates above the liquid surface. Under equilibrium conditions, the generated vapour produces a pressure corresponding to the saturation temperature of the water.

Pressure and temperature readings are recorded at suitable intervals during heating.

The experimental data can then be plotted as:

Saturation Pressure vs. Saturation Temperature

The resulting curve demonstrates the thermodynamic relationship between the vapour pressure and temperature of water.

Marcet Boiler Principle

The Marcet Boiler demonstrates the relationship between the absolute pressure and saturation temperature of water.

When liquid water and its vapour coexist in thermodynamic equilibrium:

P = f(T)

Where:

• P = Saturation pressure
• T = Saturation temperature

This means that for saturated water, pressure and temperature are not independent properties.

Increasing the temperature results in an increase in saturation pressure.

Vapour Pressure Curve of Water

One of the main experiments performed with the apparatus is the recording of the vapour-pressure curve of water.

Students take pressure and temperature readings at several operating points and plot them graphically.

This helps demonstrate:

• Increase in vapour pressure with temperature
• Saturation behaviour of water
• Liquid-vapour equilibrium
• Relationship between thermodynamic properties
• Interpretation of steam-table data

Pressure-Temperature Relationship

The apparatus provides a direct practical demonstration of the relationship between pressure and temperature in a closed water-steam system.

Students can compare experimental readings with theoretical saturation values obtained from standard steam tables.

This provides valuable experience in analyzing experimental error and understanding real thermodynamic measurements.

Main Components

• Stainless steel Marcet boiler vessel
• Electrical heating element
• Pressure gauge
• Temperature measuring arrangement
• Pressure connections
• Safety / pressure control fittings
• Steam and water valves
• Drain arrangement
• Interconnecting piping
• Electrical control unit
• Heater ON/OFF control
• Electrical safety switch
• Supporting frame
• Rigid laboratory base

Key Features

• Designed for vapour-pressure experiments
• Demonstrates pressure-temperature relationship
• Records vapour-pressure curve of water
• Simultaneous temperature and pressure measurement
• Closed-system thermodynamic experiment
• Stainless steel pressure vessel
• Controlled electrical heating
• Pressure gauge provided
• Temperature measurement provided
• Integrated valves and piping
• Separate electrical control unit
• Compact bench-mounted construction
• Suitable for steam-property studies
• Simple experimental operation
• Robust laboratory construction
• Suitable for repeated student experiments

Technical Specifications

Exact vessel capacity, heater rating, pressure range, temperature range, sensor type, and electrical requirements can be configured according to laboratory specifications.

Experiments / Studies

• To record the vapour-pressure curve of water
• To determine the relationship between pressure and temperature
• To study saturation pressure of water
• To study saturation temperature
• To investigate liquid-vapour equilibrium
• To study saturated steam formation
• To measure temperature and pressure in a closed system
• To compare experimental values with steam-table data
• To study phase-change behaviour of water
• To understand thermodynamic equilibrium
• To analyze pressure-temperature characteristics

Experimental Procedure Overview

The vessel is filled with the specified quantity of water and prepared according to the operating instructions. The electrical heater is then switched on to increase the water temperature.

Pressure and temperature readings are recorded at selected operating points. Once sufficient data have been obtained, a graph of saturation pressure against saturation temperature can be prepared.

The measured values can then be compared with standard thermodynamic data for water.

Operation of a heated pressurized vessel should always follow the supplied laboratory operating and safety instructions.

Educational Benefits

• Demonstrates saturation properties practically
• Provides hands-on thermodynamics experience
• Shows the pressure-temperature relationship clearly
• Helps students understand saturated steam
• Demonstrates liquid-vapour equilibrium
• Enables vapour-pressure curve plotting
• Supports comparison with steam tables
• Develops pressure and temperature measurement skills
• Connects thermodynamic theory with practical observations
• Suitable for individual and group experiments
• Useful for engineering laboratory examinations
• Supports undergraduate thermodynamics curricula

Applications

• Thermodynamics Laboratories
• Thermal Engineering Laboratories
• Mechanical Engineering Laboratories
• Chemical Engineering Laboratories
• Energy Engineering Laboratories
• Engineering Colleges
• Universities
• Polytechnic Institutes
• Technical Training Institutes
• Research Laboratories
• Engineering Training Centers
• Steam Engineering Laboratories

Optional Accessories

• Digital Pressure Indicator
• Digital Temperature Indicator
• Additional Temperature Sensor
• Digital Pressure Sensor
• Data Acquisition System
• Computer Interface
• Data Logging System
• Additional Pressure Gauge
• Calibration Accessories
• Experimental Manual

Customization Options

The Vapour Pressure of Water – Marcet Boiler Apparatus can be customized with:

• Different vessel capacities
• Different heater capacities
• Digital pressure measurement
• Digital temperature measurement
• Additional temperature sensors
• Enhanced safety controls
• Data acquisition system
• Computerized data logging
• Customized control panel
• Research-oriented instrumentation

SKU System

MT-FHT-201

FAQs

What is a Marcet Boiler Apparatus?

A Marcet Boiler is a thermodynamics laboratory apparatus used to investigate the relationship between the saturation pressure and saturation temperature of water in a closed heated vessel.

What is the main experiment performed with this apparatus?

The primary experiment is to record the vapour-pressure curve of water by simultaneously measuring pressure and temperature.

What is the working fluid?

The standard working fluid for the experiment is water.

What is demonstrated by the Marcet Boiler experiment?

It demonstrates that the saturation pressure of water changes with saturation temperature and helps students understand liquid-vapour equilibrium.

Can experimental readings be compared with steam tables?

Yes. Recorded pressure and temperature values can be compared with standard saturated-water and steam-property data.

Does the apparatus measure both pressure and temperature?

Yes. The apparatus incorporates arrangements for pressure and temperature measurement.

What is saturation pressure?

Saturation pressure is the pressure at which liquid and vapour phases of a pure substance can coexist in equilibrium at a particular temperature.

Where is the Marcet Boiler Apparatus used?

It is commonly used in thermodynamics, mechanical engineering, thermal engineering, chemical engineering, and energy engineering laboratories.

Can the apparatus be customized?

Yes. Micro Technologies can customize vessel capacity, heater rating, instrumentation, pressure and temperature measurement, controls, and data acquisition according to laboratory requirements.

Why Choose Our Products

• Practical vapour-pressure experiment
• Clear pressure-temperature relationship study
• Saturated steam property demonstration
• Stainless steel experimental vessel
• Integrated pressure and temperature measurement
• Controlled electrical heating
• Compact laboratory construction
• Suitable for thermodynamics curricula
• Custom configurations available
• Institutional and project supply
• OEM requirements supported
• Technical and after-sales support

Call to Action

Equip your thermodynamics laboratory with the Vapour Pressure of Water – Marcet Boiler Apparatus from Micro Technologies for practical study of saturation pressure, temperature, and steam properties. Contact us for technical specifications, customized configurations, institutional quotations, laboratory projects, OEM requirements, tenders, and bulk supply.