We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is an Overflow Valve?

Mary McMahon
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

An overflow valve is a device commonly used in plumbing, electricity generation, and other applications in which pipes conduct pressurized materials to maintain pressure on the line above the valve. It can also be installed as a safety device to prevent pressure buildup, and when used in combination with sensors and alarms, it can alert an operator to a problem along the line. Many consumers have a valve or two around their homes, especially those who use propane fuel for heating and cooking. In most cases, it has a pressure dial mounted on it, indicating the condition of the line.

This valve works by sensing the pressure up pipe from itself. It has a specified pressure level, which it maintains by use of a coil spring mechanism, which opens when the inlet, or downstream pressure, begins to rise while the upstream pressure goes down. In an emergency situation in which the inlet pressure is too high, some overflow valves are designed to alert operators, while others may fail. Individuals intending to install this type of valve should consider their needs and select the most appropriate one.

When installing an overflow valve, it is recommended that the rated pressure exceed the maximum system pressure, which will prevent failure except in the case of extreme catastrophe. The installation of a safety shut off valve up pipe from the overflow valve can also be used to prevent excessive pressure within the system. It is also recommended that they be protected from particulate matter that may be carried in the piping by use of an installed and frequently serviced filter down the pipe.

Usually, cut off valves are located up pipe and down pipe of the overflow valve, allowing access for maintenance and replacement. If total shut down of the system is not a possibility, be sure to install a bypass line so that the system can continue to operate while the valve is being serviced. In the case of hazardous materials, an overflow valve should include good seals and a leakage line to contain potential spills.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a About Mechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments

By morgan — On Dec 10, 2008

it's a very knowledgeable website.

By shower123 — On Jul 16, 2007

Should my bathroom shower shut-off valve be gushing a sizable amount of water during the shower?

Mary McMahon

Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.