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Vacuum Breaker on a Shell & Tube Heat ExchangerWhen it comes to keeping your heat exchanger running smoothly, a small device called a vacuum breaker plays a big role. Think of it as a safety valve that prevents your system from turning into a steam-powered implosion.

What Is a Vacuum Breaker?

A vacuum breaker is a simple, spring-loaded valve that allows air into a closed system when internal pressure drops below atmospheric pressure. In steam systems, this prevents a vacuum from forming as steam condenses—avoiding damage and performance issues.

Why Heat Exchangers Warrant Vacuum Breakers

In a shell-and-tube heat exchanger, steam condenses inside the shell to transfer heat to the fluid in the tubes. As it condenses, it can create a vacuum, which introduces two types of problems:

  1. Mechanical Risk: If the shell isn’t strong enough to handle the pressure differential, it can collapse—think of crushing an empty soda can. A vacuum breaker prevents this. Vacuum conditions can also cause water hammer when steam rushes back in, leading to loud noises and potential damage.
  2. Performance Impact: Even if the exchanger is mechanically rated for vacuum, some processes aren’t designed to operate under vacuum pressure. It can alter the thermal or mechanical properties of fluids, hinder condensate drainage, and cause the system to operate inefficiently.

Installing a vacuum breaker allows air to enter the shell, equalizing pressure and preventing these issues.

Installing a Vacuum Breaker: Best Practices

Proper installation is key to ensuring your vacuum breaker functions correctly:

  1. Location: Install the vacuum breaker at the top of the heat exchanger shell or on the steam supply line near the exchanger. This placement allows air to enter where the vacuum forms.
  2. Orientation: Mount the vacuum breaker vertically with the cap facing upward to ensure proper operation.
  3. Isolation Valve: Include an isolation valve below the vacuum breaker to facilitate maintenance without shutting down the entire system.
  4. Maintenance: Periodically inspect the vacuum breaker for debris or wear. While many models are not repairable, regular checks can prevent unexpected failures.

Vacuum Breakers on Enerquip Shell & Tube Heat Exchangers

So, where does Enerquip fit into this?

Our standard heat exchangers—also known as tabulated or stock designs—are engineered to withstand vacuum conditions. That means they’re strong enough to avoid collapse without needing a vacuum breaker for mechanical reasons.

However, larger or custom units may not be rated for vacuum by default. That’s because vacuum-rated designs often require thicker materials, which can significantly increase cost. In these cases, we calculate for vacuum only if requested.

From a performance standpoint, though, even a structurally robust system may require a vacuum breaker or pressure relief device installed on the exchanger or in the process piping to ensure the system operates as expected. That’s why nearly every Enerquip exchanger includes a small vent connection on the shell—giving you (or your installer) the flexibility to add a vacuum breaker when needed.

Bottom Line

Incorporating a vacuum breaker into your heat exchanger system is a small investment that can prevent damage and downtime. By allowing air into the system when needed, it maintains pressure balance and ensures efficient operation. Regular maintenance and proper installation are key to maximizing its benefits.

Want help optimizing your heat exchanger setup? Contact the Enerquip team today.

 

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