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#69 -- Test and Drain Valve: A Guide for Fire Sprinkler Contractors

Posted by Jason Hugo and Anna Hartenbach on 8/10/2017 to Valves
Ask any knowledgeable fire sprinkler contractor and they’ll tell you that a Test and Drain valve is a pretty handy device when installed in a fire sprinkler system. It’s dual-purpose design enables system draining, when required, but also aids in required testing. 

But what’s the real benefit of a Test and Drain valve? One could easily drain the system with a ball valve, right? 

That’s what we’re here to discuss in detail! In this article, we’ll inspect (pun intended) the Test & Drain to uncover its benefits, uses, and features. As we’re known to do, this article digs into the relevant NFPA Code so we can help you put their suggested rules and guidance into perspective and understand why it matters to you – the fitter, the contractor, and the building owner!

Looking for a Test and Drain valve? Feel free to skip directly to our selection of in-stock Test and Drains from AGF and Lansdale. 

Otherwise, let’s start with the basics, shall we?

What is a Test and Drain?

A Test and Drain is a type of valve with both a test function and express drain function. Think of a ball valve and Inspector’s Test combination, except it’s manufactured as one unit making it much more convenient. 

Similar to the compact, easy-to-use nature of commercial and residential risers sets, Test & Drains are a step forward for the fire protection industry as they simplify the installation of the system by cutting out extra components. In comparison to a standard ball valve and an Inspector’s Test valve, a Test and Drain means lower cost, less parts, easier installation, and multiple uses. With an all-in-one design, Test and Drain valves come standard with common features:
  • Single handle ball valve
  • A 5.6K or 8.0K test orifice
  • Tamper resistant sight glass
  • Tapped and plugged port for system access

Test and Drain valves come in a variety of sizes, with specific orifice sizing options as well (we’ll discuss the importance of this in a bit). To readily serve the various system and installation needs, Test and Drains come in various styles with additional features. However, before we can go much further, it’s important to see how the NFPA views Test and Drain valves.

Is the Test and Drain Valve NFPA Compliant?

In short, yes, the use of a Test and Drain is NFPA compliant. 

In a previous article, we discussed the use of ball or Test and Drain valves on commercial and residential risers. Upon first look at Valves (6.6 and subsections) in NFPA 13, it seems a bit vague when it comes to Test and Drains specifically.

From the 2016 Edition of NFPA 13:
6.6.3Drain valves and test valves shall be approved.

That’s it? Really, that’s it. 

Their reasoning is that neither drain or test valves are essential to the primary function of a fire sprinkler system. But they exist and are approved for use within the system. 

According to NFPA 13, one of the most common reasons a fire sprinkler system fails stems from a closed valve. Therefore, the NFPA 13 devotes considerable time to educating and preventing such occurrences. This is where a Test and Drain becomes beneficial for use within a fire sprinkler system. 

What are the uses and benefits of a Test and Drain?

The uses and benefits of a Test and Drain largely serve the installation and applications of a wet pipe fire sprinkler systems.

From the 2016 Edition of NFPA 13:
3.4.11 Wet Pipe Sprinkler System – A sprinkler system employing automatic sprinklers attached to a piping system containing water and connected to a water supply so that water discharges immediately from sprinklers opened by heat from a fire.

Wet pipe systems are undoubtedly the “Ole Reliable” in the fire sprinkler industry. They’re known for their simplistic design and consistent functionality. Other systems – like dry or deluge – require more equipment, which provides more potential for system failures and shortcomings.

Because of this, the majority of Test & Drains are built to meet the needs of wet fire sprinkler systems. Specifically, the drain function allows the system to be drained quickly and the test function is beneficial for system testing. This helps to evaluate the water supply and ensure it’s readily available at the riser and on the system side of the main check valve.

From the 2016 Edition of NFPA 13:*Provisions shall be made to properly drain all parts of the system. the main drain connection so that it can flow the sprinkler system demand flow rate provides practical means for performing the forward flow test of the backflow device as required by shall discharge outside or to a drain connection capable of handling the flow of the drain.

Since a Test and Drain does have the ability to drain the system, they can serve as the main drain on a wet pipe system ( Furthermore, they can replace ball valves on commercial or residential risers. 

The major benefit to a Test and Drain is its ability to perform necessary system testing in accordance with NFPA 25. They are equipped with a sight glass to provide visual confirmation of water flow through the system. 

From the 2016 Edition of NFPA 13: test connection valve shall be accessible. discharge shall be to the outside, to a drain connection capable of accepting full flow under system pressure, or to another location where water damage will not result. alarm test connection shall be permitted to be installed in any location on a fire sprinkler system downstream of the waterflow alarm.

As stated above, there is not a specific location requirement for the Test and Drain. More traditional inspector’s test valves were at the end of the system, which is very useful for identifying clogs in the system. However, Test and Drains are commonly found as part of the riser assembly, and therefore not necessarily at the end of the system. This is A-OK! 

In a combination sprinkler/standpipe system, the Test and Drain valve is beneficial because it helps facilitate flow testing. In order to do so, the valve must be positioned downstream of the floor control valve and connected to a drain riser. Test and Drain valves have an orifice capable of simulating the discharge of a 5.6 K sprinkler head, which tests the floor’s flow switch. In this testing scenario, the water flow alarm should set off within 90 seconds. Through the water flow test, the alarm system and panel undergoes testing as well, as it should indicate the flow of water.

Additionally, a Test & Drain can provide system security and a controlled testing environment. When used on a commercial or residential riser in a riser room, the test function is not accessible to the public and removes the risk of tampering and setting off alarms. Furthermore, the riser room can be controlled and regulated allowing for a localized, consistent and controlled testing environment. This, in and of itself, is a major benefit!

What are the requirements of a Test and Drain?

Although we covered many of the system requirements of a Test and Drain in the previous section, the valves themselves must also comply with specific code. 

Valves used with a wet pipe sprinkler system shall have a minimum working pressure of 175 psi. If the system has a higher working pressure, the valves must perform in accordance with the requirements of the system. 

According to NFPA 13 Code, valves need a minimum closure time of 5 seconds, meaning they should not close any faster. In an active system where water is flowing, a faster closure rate can result in what the NFPA describes as a “water hammer.” Water hammer occurs when the flow of water is interrupted abruptly, resulting in a pressure surge that can create leaks or damage to the system.

Furthermore, valves must have what the NFPA refers to as “limited leakage after removal of all resilient material.” The point of this is to show how the valve will perform in the instance of a fire or as it ages and ensure that a large amount of water won’t flow uncontrolled into the system in the case of drain line failure. 

As you move forward and begin the process of selecting a Test & Drain, it’s important to keep this information in mind.

What should you look for when selecting a Test and Drain for your system’s needs?

When selecting a Test and Drain to meet your system’s needs, you should first look for one that fits the requirements from the designer. It should also comply with any rules and regulations as set forth by the local Authority Having Jurisdiction (AHJ). 

As previously mentioned, select a Test and Drain with a sight glass to provide a visual confirmation of active water flow through the system. Although they come in different sizes, a Test and Drain with a ½” orifice will simulate the flow of a 5.6K sprinkler head, which is the most common size. Otherwise, a 17/32” will simulate the flow of an 8.0K fire sprinkler head, which is the second most commonly used.

Finally, make sure to select a valve that matches the pressure rating of your wet pipe sprinkler system. According to NFPA 13, the minimum working pressure shall not be less than 175 psi. 

At QRFS we offer a variety of Test and Drain valve makes and models to meet the needs of your wet pipe sprinkler system. AGF offers options with a pressure relief valve with drainage piping, pressure gauges, and three-way valves – the even make a Remote Test Test and Drain Valve. Lansdale provides a unique take on a Test and Drain valve with its patented design. All options are UL listed and FM approved. They are compliant with NFPA 13, 13R, 13D, and 25.

Additionally, when you purchase through QRFS, you benefit from our quality customer service and customer dedication. It’s our goal to remain up to date on NFPA Code and industry best practices, so we can help you make the most informed selection possible.

Still have questions? Comment below and we’ll reply as soon as possible to get your project flowing!

This blog was originally posted by Jason Hugo and Anna Hartenbach at QRFS.com/blog on August 10, 2017. If you found this article informative, check us out at Facebook.com/QuickResponseFireSupply or on Twitter @QuickResponseFS.

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