Keeping your safety shower working at optimum performance is important, no matter what time of year. However, cold winter temperatures can make this especially difficult. Water can freeze in supply lines, clogging the system and shutting off flow. And because water expands as it freezes, internal pressure in the line can increase enough to break steel pipes and their associated valves and fittings. The result can be costly replacement parts, in- creased labor costs, and a shower that’s out of commission while it’s being repaired.
Cold weather can bring other problems, too. Water that’s too cold can discourage workers from using the showers for the full 15 minutes as recommended by ANSI and OSHA standards, thereby contributing to worker injury. Although federal regulations such as OSHA’s 29 CFR 1910 do not mandate every detail of safety shower systems, they do specifically require safe work- place conditions. Unless you provide comfortable water for safety showers, these regulations can be easily interpreted to result in safety violations.
There are a number of steps you can take to prevent cold weather from interfering with safety shower performance. Many are relatively simple to implement and can be readily put in place before cold weather begins.
How Water Freezes: The Science of Temperature and Expansion
Water, when it freezes, changes from liquid to solid. As the temperature drops, the molecules become less energetic, moving more slowly, until they reach a point at which the molecular structure changes, followed by the transformation into ice, or solid water. Unlike most substances which shrink in volume as they freeze, water expands since ice’s molecular structure takes up more space than water. Conversely, when you heat water, the molecules become more excited until they reach the point where the water vaporizes and becomes steam.
There is a misconception that if water can be kept moving, it won’t freeze. Wrong! Water freezes at 32°F (0°C). Period.
Why Do I Need Freeze Protection for My Pipes?
Since the expansion of water as it freezes is a fact of life, what things should we know about this process in order to create effective means of dealing with it in industry? Water that has frozen in piping systems does more than simply clog the system and shut off the flow. Because ice takes up more room than
liquid, when freezing occurs in a confined space like a steel pipe, the ice will build up extreme internal pressure which is often enough to break the pipe and its associated valves and fittings.
Damage from a burst pipe or valve can escalate beyond just replacing the broken parts, into labor costs for the repair and time/money lost from “down-time” in the affected area. Before effective measures can be taken to prevent such disasters, we need to learn about and understand what is happening.
The Physical Principles of Freezing
What are the underlying principles that determine whether the water in a given device (pipe, valve, etc.) will freeze? We already know that water freezes at 32°F. To arrive at this temperature, heat must be removed (transferred) from the water (Remember – heat always travels from high temperature areas to lower temperature areas). Heat transfer, or the removal of heat from one place to another (i.e. from the 45°F water inside a pipe to the 25°F air outside a pipe) is one of the basic laws of nature. Heat is a form of energy. Others include chemical, electrical, mechanical and nuclear, and each is convertible from one form to another. In the USA, heat is usually measured in BTUs, or British Thermal Units. One BTU is the amount of energy which, when added to one pound of water, will raise the temperature of that water by one Fahrenheit degree (as from 65°F to 66°F).
Warminster, PA (January 22, 2012) It’s hard to imagine a crueler fate for Fred Pirkle, an inventor whose 65-year-old hands have been in creative motion since he was a boy growing up in Texas.
“The first time I stood next to a lathe,” the Bucks County manufacturing executive recalled, “I was shivering all over. I was excited as I could be.”
The first time he got to run a lathe? “I was almost paralyzed with excitement,” Pirkle said.
Today, the excitement is still there, though a fast-moving form of amyotrophic lateral sclerosis, more familiarly known as Lou Gehrig’s disease, has shut down virtually all Pirkle’s voluntary muscle movement.
We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept”, you consent to the use of ALL the cookies.
This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may have an effect on your browsing experience.
Keeping your safety shower working at optimum performance is important, no matter what time of year. However, cold winter temperatures can make this especially difficult. Water can freeze in supply lines, clogging the system and shutting off flow. And because water expands as it freezes, internal pressure in the line can increase enough to break steel pipes and their associated valves and fittings. The result can be costly replacement parts, in- creased labor costs, and a shower that’s out of commission while it’s being repaired.