The critical process of accurately calculating and correctly positioning an expansion vessel is crucial in designing and operating heating and cooling systems.

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"The software offers precision through detailed result outputs and advanced options for efficient pipe sizing, allowing heating engineers to optimise based on parameters like maximum velocity and pressure drop."

The transformation of industries by the digital revolution is a story told many times over, and heating system design is no exception.

Stray current produces a high number of anodes & cathodes that can inadvertently enter an alternate (but unintended) path and create corrosion in the piping system.

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Embracing the digital revolution in the form of heating design software, like that offered by h2x Engineering, is crucial for professionals who wish to stay competitive in the industry.

With the right software, like h2x Engineering’s Heating Design Software, you can drive efficiency and accuracy in your heating system projects.

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These vital components, also known as expansion tanks, are pivotal in maintaining system safety and operational efficiency.

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Dielectric unions provide insulation between incompatible materials for joining them safely. They avoid electrolysis, which leads to corrosion or pipe failure. They are ideal for pipe sizes ranging from 3/4 to 4 inches.

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This number will vary based on your geographical location and the associated climate but will likely be around 5°C (41°F) in the winter months.

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Consider a system with a water volume of 500L, an initial temperature (T_initial) of 10°C, and a maximum operating temperature (T_max) of 80°C.

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They counterbalance changes in fluid volume, and consequently pressure fluctuations, which occur due to variations in temperature.

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Tailpieces allow connecting ends of two dissimilar pipe systems so that liquid can be safely transported with minimal leakage.

When dielectric unions are connected between two dissimilar pipes, they ground the electric current and break continuity for complete insulation between the two environments.

CASE STUDIES Greengate, UK "I would estimate over the length of this project, I have spent 50% less time designing than I would on our previous software. The ability to output the design straight into Revit assisted clash detection and coordination." Read the full case study

"I would estimate over the length of this project, I have spent 50% less time designing than I would on our previous software.

– Incorrect positioning: this can disrupt the vessel’s primary function of accommodating fluid volume changes, potentially leading to dangerous pressure build-ups or operational inefficiencies.

Ideally, they should be placed in a cooler section of the system, for instance, the return pipe close to the boiler or chiller.

Gain a comprehensive understanding of expansion vessels inside this informative blog. Includes a calculation example for practical insights.

Watts LF3004 Series dielectric unions are used in commercial and industrial applications to prevent accelerated corrosion and deterioration in piping systems caused by galvanic and stray currents. They are installed between pipes made from dissimilar metals. These dielectric unions feature steel / iron / galvanised malleable iron / malleable iron & galvanised steel construction for structural rigidity and long service life. They have polysulfone insulation to prevent electrical hazards during operations and come with Buna-N gaskets for secure & reliable sealing between the pipes.

The expansion vessel provides the necessary ‘give’ in the system to handle this extra volume, preventing potential over-pressurisation damage.

Dielectric unionFor gas piping

3 bar (300 kPa / 43.5 psi) is commonly used for this (recommended by CIBSE) but the manufacturer’s documentation is typically the best source for this information.

The maximum allowable pressure is the peak pressure that a system can safely tolerate without causing damage to its components or risking a system failure.

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Give your heating system designs the h2x advantage and experience the difference by booking a demo or by starting your free trial today!

Expansion vessels are required in systems where a closed circuit is subjected to a fluctuation in temperature e.g. heating and cooling systems.

Having understood the crucial parameters, we now venture into the specifics of calculating the size of an expansion vessel.

As the water heats up, it expands, and without a place to go, this increase in volume can cause a dramatic rise in pressure.

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Watts dielectric unions are used in HVAC equipment, hot water storage tanks, and piping system for reducing the deterioration and accelerated corrosion caused due to stray and galvanic currents. These unions are capable of withstanding temperatures and pressures up to 180 degrees F and 250 psi, respectively. They are offered in FIP, MIP & solder connection options, to allow easy installation on pipe sizes ranging from 1/2 to 4 inches, on Raptor Supplies.

The strategic placement of heat pumps and careful sizing of pipework were crucial in maintaining minimal pressure drops over an 18-metre distance."

Watts LF3003 Series dielectric unions are installed at the junction of pipes with varying metal compositions, such as water heaters or pumps, to isolate the metals and reduce potential corrosion caused by electrolysis. These unions effectively maintain water quality and extend the lifespan of plumbing systems by preventing leaks and deterioration due to the chemical reactions caused by metal interaction. The brand's LF3003 Series dielectric unions safeguard water distribution systems, ensuring reliability and durability. They come with a comprehensive assembly consisting of a union nut, two tailpieces and a gasket. This combination creates a robust barrier against electric currents, effectively preventing galvanic corrosion. They have a design with a female iron pipe thread to female brass pipe thread connection, facilitating seamless integration and secure attachment between different types of pipes. These dielectric unions have Buna-N gasket, preventing leakage.

This data can usually be found within the system’s design specifications. In cases where it’s not readily available, a pressure gauge might be needed to measure this pressure.

This level of detail ensured that the heating load accurately matched each space's requirements, minimising energy waste and maximising comfort.

CASE STUDIES Salon Republic, USA "The quality of the designs saw significant improvement with the adoption of h2x." "The software offers precision through detailed result outputs and advanced options for efficient pipe sizing, allowing heating engineers to optimise based on parameters like maximum velocity and pressure drop." Read the full case study

An expansion vessel, or expansion tank, is a device in a heating or cooling system that accommodates the extra volume of water produced when the system water is heated or cooled.

CASE STUDIES Award-Winning Heating Design "Using h2x was pivotal, allowing for precise heat loss calculations, pipe sizing and flow rates for each room. This level of detail ensured that the heating load accurately matched each space's requirements, minimising energy waste and maximising comfort. The strategic placement of heat pumps and careful sizing of pipework were crucial in maintaining minimal pressure drops over an 18-metre distance." Read the full case study

Moreover, to avoid the issue of pump cavitation, installing the vessel on the suction side of the recirculation pump is recommended.