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Steam Traps Explained: What Function Do They Perform in Your Boiler System?

As a property owner in New York City having work done on your boiler, you might have heard your service professionals talking about steam traps. Are steam traps still a mystery to you? If you’ve ever wanted steam traps explained, this is the blog post for you. Here’s the basic information you need, as well as facts about common problems we often see with our clients’ team traps.

First of All, Let’s Define Steam

The third phase of matter

To understand how steam traps work, it’s essential to go back to school and review what, exactly, steam is. You might recall from high school science classes that matter has different phases. Steam is one of the phases of water.

Below the freezing point, water is a solid: ice. When ice melts, which happens above 32 degrees Fahrenheit, it becomes a liquid.

When water exceeds the boiling point of 212 degrees Fahrenheit, it becomes a gas: steam. This is the steam we tap for radiator heat in so many New York City apartments each winter.

Here’s a bit of trivia for you. There are two more phases of matter beyond gas: plasma and Bose-Einstein condensates. Fortunately, we don’t have to trouble with those when working on boilers!

The Function of Steam Traps

Conservation of steam only

Steam traps are designed to keep steam generated by a boiler in the system so it can be reused. Trapping steam saves energy, which is not only good for the environment but good for your wallet as a property owner.

Steam traps remove air and condensate to hold pure steam. Condensate is steam that has cooled below 212 degrees (condensed) and returned to the liquid state. It has to be funneled back into the boiler via a tank and reheated before it can be used for heat again.

Removing condensate from the steam in your boiler system is essential. Leaving condensate in your steam can cause water hammer in your radiators and pipes. It can also result in corrosion. It makes the steam less efficient, which is undesirable.

Types of Steam Traps

Which do you have?

Depending on the size of your boiler system, you may have one steam trap, or you may have dozens distributed along the length of your steam pipes. The larger the property, the more likely you have multiple steam traps. Steam traps have a few different nicknames, but they can be identified by their basic mechanism of action.

By far, the most common type of steam trap is the mechanical trap, which uses a simple but elegant way of catching steam. A mechanical trap uses a float that detects the difference in density between steam and condensate. This type of trap resembles a bucket in its anatomy.

There are also thermostatic steam traps. As the name implies, they rely on temperature differentials to perform. They detect differences in temperature between steam and condensate at the same pressure. A sensor operates a valve that lets the unwanted condensate drain out. One advantage of thermostatic steam traps is that they are relatively easy to repair.

Less frequently used, thermodynamic traps utilize both pressure variations and volumetrics to distinguish between steam and condensate. This type of steam trap is smaller and less expensive, but it does lose some steam in the process, making it less efficient too.

Common Steam Trap Problems

The wrong steam trap for the boiler system

There are a number of places where a steam trap can go wrong, but you’ll never get efficient reuse of steam and removal of condensate if you don’t have the right trap to begin with. This is why it’s essential to have your steam trap installed by boiler experts and reassessed any time you make changes to the boiler system. The size of your property, the type of boiler you use, and your steam distribution structure all influence what type of steam trap is appropriate.

Failing in the open position

When steam traps fail, it’s usually when they’re open or closed (see below). Malfunctioning in the open mode is a more common occurrence. When this happens, you’ll find your boiler working harder than normal to produce the same amount of steam, which increases wear and tear on the boiler and ends up costing you money. You may have tenants complaining that they aren’t getting enough heat because there isn’t enough steam going to their radiators.

Failing in the closed position

Boilers that fail in the closed position have more condensate accumulating because it’s not released back into the boiler. Again, you won’t be able to produce enough heat but for different reasons. You may hear water hammer, too, when this occurs.

Other steam trap problems

We’ve been servicing boilers in New York City for nearly a century. During that time, we’ve seen all kinds of steam trap problems. Some other issues our clients run into include:

• Oversized steam traps – in addition to choosing the wrong type of steam trap for a property it’s possible to install the wrong size too, causing the trap system to work harder than it has to
• Dirt in the system – dirt is common in steam systems due to pipe scale, lack of proper water filtration, and the overuse of chemicals in boiler treatment, and it can cause clogging of valves and the malfunction of other steam trap parts.

Call Calray Boilers for Help with Your Steam Trap

New York City’s top boiler professionals

Before the next heat season begins this fall, it’s wise to have your entire boiler system checked and maintained by boiler experts like Calray Boilers. We can make sure your steam traps are ready to go once you start using radiators on your property. And of course, we’re available for steam trap problems during the colder months, should a concern arise. We use the latest technology, including visual, thermal, and acoustic inspections, to make sure your steam traps are performing as they should.

Call Calray Boilers today at 212-733-5506 to schedule a maintenance visit, or use our easy online form to book an appointment at your convenience.