Introduction to Grooved Pipe & Fittings
We previously have introduced different types and combinations of threaded fittings - which have been around for more than a century.
Here we're introducing another common way to join pipe; using grooved fittings.
An attic sprinkler system using a grooved elbow with couplings.
Use of "mechanical" couplings that could allow faster joining of pipe came to life in 1919 by Lieutenant Ernest Tribe. Just a few years later the Victory Pipe Joint Company renamed itself to Victaulic (a combination of "victory" and "hydraulic"), and grew to expand the technology worldwide.
Today, Victaulic and other manufacturing leaders provide grooved fittings that are often used for pipes in fire sprinkler systems. It is not uncommon for both mains and branch lines to be grooved today.
What are common grooved fittings, and how do they work? Let's introduce them.
An in-rack sprinkler with a branch line using (starting with the sprinkler) a groove x thread reducing elbow
with a grooved coupling, a grooved piece of pipe, and a grooved tee (connection not shown).
Let's start with the pipe. In order to give grooved fittings an opportunity to "grip" the pipe and remain in place, they need an opportunity to resist the pressure of the water that is trying to "pull away" the pipe from the fittings which join them together.
A grooved coupling about to connect two grooved-end pipes. Note the loose nut and bolt on the right-hand side, allowing the coupling to be expanded and "slip" over the pipe on the left.
In order to create a groove in the pipe, steel can either be "roll groove" or "cut groove". Roll groove pipe involves pressing an indentation into the pipe near the end of the pipe. This allows a grooved fitting to slip over the end of the pipe and fit into the groove. Roll groove pipe has the advantage of not reducing the pipe thickness, so it can have more tolerance for corrosion than thinner pipe, similar pipe with threads, or pipe with cut grooves.
Pipe which is cut groove involves cutting into the pipe rather than pressing it. This cutting removes a portion of the pipe wall, making a thinner but smooth interior pipe wall. This thinner wall makes it more susceptible to corrosion, however, for pipe systems with a minor slope, the smooth inside of the pipe does not create a ridge where water can sit and corrode the pipe.
Roll Grooved Pipe (top) and Cut Grooved Pipe (bottom). Note the ridge on the inside of the pipe wall for roll groove pipe, and the thinner pipe wall along the cut groove pipe.
A tape measure with a "go" or "no-go" measurement to determine if the groove is within manufacturer tolerances.
ELBOWS & TEES
Let's start with the basics. Elbows allow bends of 90-degrees (most common), 45-degrees, 22-1/2 degrees, and 11-1/4 degrees.
Why not every possible angle? What if I need to have a 60-degree bend because of my building?
First, it wouldn't be economical to make a fitting of every bend. Second, is that using just two 90-degree elbows back-to-back we're able to create a "swing joint" and make any angle we could want, just by changing the elevation of the pipe that's being joined.
Victaulic "FireLock" Grooved Fittings;
90-Degree Elbow #001 (left), 45-Degree Elbow #003 (center), and Standard Tee #002 (right)
One notable specialty with the grooved elbow is a "Drain Elbow", which has the elbow except it includes a drain outlet at the bend of the elbow. This is used all the time with fire department connections which come down a wall and need to be capable of being drained (to avoid having water-charged pipe freeze and burst). This is also called a "Drain-El" or is a Victaulic #10-DR.
A wall-mounted fire department connection that is away from the riser, here showing the "Drain Elbow" with a ball drip below. The portion upstream of the check valve is intended to be dry unless the FDC is actively being used in order to avoid freezing water inside.
Nice sketches, Joe, but that's not how things look in the field!
That's because unlike threaded fittings, the actual pipe joining is by a grooved coupling. The coupling has malleable iron bumps that grip the indent of one groove (pipe/fitting) and connect it to the second groove (the other pipe/fitting).
A grooved coupling (here a Victaulic #009N shown).
There are a host of other fitting types. Grooved Reducing Tees? Yep. Less common. Less common can equate to more expensive, or at least that's what I hear from contractors familiar with all the pricing nuances.
What other grooved fittings do I often see?
Reducing fittings, which is a concentric, single-cast piece of metal that has a large groove on one end and tapers down to a smaller groove on another end. One note of caution is using these in the vertical orientation; I've heard it is much better, more stable, and stronger to use a reducing-fitting as opposed to a reducing-coupling when in a vertical orientation. One of my clients goes so far to say to not use reducing couplings at all (where the coupling itself has two different groove sizes). I wouldn't have the expertise to gauge that myself.
A flange x groove reducer (left) and a grooved cap (right).
There are also reducing adapters, than can accept a flange connection and convert it to a reduced groove connection.
Crosses are also available, as are caps (like the Victaulic #006 shown above on the right) which can terminate the end of a branch line. These caps even have 1-inch threaded opening options for easy auxiliary drains.
Many manufacturers have equipment and components with grooved ends that can readily attach to pipe and fittings.
If you're looking to explore the extend of all available grooved fittings, I'd invite you to check out manufacturer's catalogs or do a simple google search for grooved sprinkler pipe fittings. The manufacturer's product data can do a whole lot of good in clarifying what's been created and listed for use in sprinkler systems.
Have tips, tricks, or things to consider about grooved fittings? Comment below.
That's all for this week - hope you have a great rest of yours.
A New Sprinkler Spacing Flowchart (PDF)
When teaching the basics of sprinkler layout, I find it far too easy to jump right to talking about sprinkler spacing distances and the coverage area in relatable terms.
SPRINKLER SPACING AS 225 SQFT & 15x15
I say that a sprinkler is limited by a coverage area limit, and by a maximum spacing. I then introduce an example for Light Hazard with an acoustical ceiling tile, and explain that the limits are 225 sqft and 15-ft x 15-ft.
That's all technically correct. And, as an example, it's a common one for those of us that work regularly with light commercial buildings.
However, by giving that example, there is a whole series of assumptions built in that I completely gloss over.
UNDERSTANDING THE PATH
Experienced Designers & Engineers will tell you (they've told me), that to teach the fundamentals correctly we really need to start with all the considerations and assumptions that go into a sprinkler layout.
Is the structure combustible, noncombustible, or limited-combustible?
Is the construction Obstructed or Unobstructed?
Are we assuming standard-spray sprinklers, or something like ESFR or Extended Coverage?
I've gotten caught making basic mistakes - spacing sidewalls inappropriately because I just assumed that a 14x14 spacing applied regardless of the construction type.
I could be wrong here, but my guess is that even experienced people have made the same mistakes I have on sprinkler spacing because we've glossed over the combustible nature of the ceiling.
A new sprinkler spacing flowchart. Click above to download.
A PDF FLOWCHART
Partially to satisfy my own curiosity, and partially because we're getting into a lot of detail with teaching these concepts on the University platform (all our PDF resources are there), I've broken out these different paths and decision trees in a new pdf flowchart. Click above to download the full PDF version.
Unlike some of the other charts and checklists we've created, this probably isn't one I'm going to be referencing daily. There's typically only a few common limitations that apply to most of the work that I do.
However, just as a concept, I find it interesting how the considerations of combustible/noncombustible construction, obstructed and unobstructed, exposed members versus non-exposed members all play a part in how NFPA 13 tells us to properly protect each space. This can be helpful as a teaching tool in introducing the spacing concepts.
Hope you have a great rest of your week!
This week I'm happy to debut an update to one of our popular tools, the K-Factor selector, which is a part of the Toolkit.
This tool quickly calculates the actual pressure and flow across different types of sprinklers. It's helpful when we're trying to select the best-possible sprinkler for a hazard.
Even for light hazard areas, a standard k5.6 sprinkler may not be the 'optimal' sprinkler, from a hydraulic perspective. We touched on this when looking at whether the flow through a sprinkler is governed by the density and area or by the k-factor and minimum pressure.
In short, the minimum flow through a sprinkler can be driven by the coverage area of the sprinkler multiplied by the density of the hazard, or, it can be driven by the k-factor of the sprinkler and the minimum pressure that sprinkler requires.
In either case, it's important to make a quality selection for the k-factor if we want to reduce the required pressure and flow that a system will demand. Less flow usually means less friction loss, which can result in more efficient systems and smaller pipe sizes (saved cost of material and labor).
The updates to this tool make it mobile and tablet friendly, and also now clearly indicate what the 'optimal' sprinkler k-factor is for flow and for pressure (hint: they're not always the same). If you're a Toolkit user, just click the image above to see the updates. Thanks!
A Remote Area Cheatsheet in Metric [PDF]
Last week we debuted a remote area cheatsheet detailing some tips for quick-response reduction, slope adjustments, and dry, double-interlock pre-action and storage area adjustments.
We're all about bringing fire protection pros around the world together (globally), and so today I'm happy to also add a metric version of this same cheatsheet. We plan do to updates like this with our content going forward.
To download, just click below. If you're a University user, you can get all of our latest cheatsheets, checklists and summaries under your University Dashboard. Thanks & have a great week!
This Remote Area cheatsheet allows for quick adjustments to the remote area and minimum remote-area widths when conducting or reviewing fire sprinkler hydraulic calculations.
A New Remote-Area Cheatsheet [PDF]
It's been too long since our last cheatsheet! Happy to bring about a new one to the table today.
One number that I seem to always need to crunch when laying out or reviewing fire sprinkler systems is the remote area adjustments, and the minimum width of a remote area. This applies specifically to the Density/Area method of Hydraulic Calculations in NFPA 13.
The formula is simple enough, w = 1.2 x sqrt(remote area size), where w is the minimum remote area width, and the remote area size is our final adjusted remote area that we're using.
Now for a routine calculation with a remote area of 1,500 sqft, I pretty much have the 46.5-foot area width memorized. Why is it important? The minimum width dimension tells us how wide our remote area needs to be. It's the dimension parallel to the branch lines, that captures as many sprinklers as it can along the branch line.
We take this minimum area, see how many sprinklers this area covers, and round up to the next whole sprinkler. It's our minimum width dimension that we're not allowed to reduce.
The 46.5-foot dimension might be easy enough to remember, but what about when a remote area is reduced using the quick-response reduction? What if the ceiling is also sloped?
Adjustments to the remote area are a process on their own, and each have implications for the minimum remote area width.
If you're using our Toolkit you already know we have tools that will compound the calculations for you. Our Quick-Response Reduction tool will adjust the remote area size based on the ceiling height, and our System Estimator tool will adjust for quick-response, sloped ceilings, dry and pre-action systems, high-temperature sprinklers, and more:
But, there are still times where I just want to quickly glance at my remote area size and translate that into a minimum width. That's what today's cheatsheet is all about.
This quick reference PDF helps address a few things:
I hope this one is helpful for you as conduct or review hydraulic calculations on your projects. Any tips, feedback or improvement ideas, be sure to let me know.
Thanks & have a great rest of your week!
A Note on Ukraine
First - you don't read articles here for my political or personal opinions, and I get that. I respect that. I very much appreciate that.
That said, I worry for my friends colleagues in Ukraine and Russia. I'm heartbroken about what they are going through right now, of which I can't imagine. I have a wife and three kids. I work with people in Ukraine who have the same young families. This past week has been tough. Nothing I feel here remotely compares to what they are facing right now. I just cannot imagine having to choose between fleeing my home country for the safety of my family or grabbing a rifle. I can't imagine it.
I wish we, as humans, could find ways to appreciate and support each other instead of violence. I wish we better embraced a perspective of mutual concern for each other over destruction. What are we - in our collective bond for fire protection - if not a group of people trying to find ways to create safe environments for public well-being? To help others? To save lives?
We're connected now. I work with people in the U.S. and all across the world - by choice - and I'm just starting to appreciate what a global attitude adds to my life. Because of this website I get to talk with fire protection people around the world, and get to hear about some of the challenges they face. We're not that different.
I don't want to pretend that my own country's history is flawless - that even our recent record is faultless. I cannot be the one to "cast the first stone." I simultaneously celebrate being an American but recognize that we have a long way to go. I pray for Ukraine and everyone involved in the conflict. I pray that our leaders, everywhere, and in any capacity, find a way to end violence quickly and recognize the value of the lives of the people they are affecting.
I genuinely wish that we all (myself included) could better appreciate each other and find ways to help and not hurt. I know you don't come here for my take, but I do appreciate you. Thank you for being here, for caring, and for being a part of our greater community that is working to make good in the world.
I've come across this question - why do we need to flow more water - from two angles: as a total rookie, and later on as someone needing to really understand a water supply.
As a newbie - I was intimidated by a few things; first, that someone would call the police on me because I didn't look like I knew what I was doing. Second, that I didn't want to destroy any landscaping. And third, I definitely didn't want to be breaking any hydrants. Those three factors made me want to keep my flow tests as calm and low-flow as possible.
However, as I was told at the time, that's not advantageous when we're trying to determine the quality of an existing water supply.
Just a year ago, I was working on a project with a marginal water supply, where the water tower and the pumps feeding it were controlled by the project owner. The tower was in some disrepair (not known to us at the time), and we were trying to figure out why we were getting such different results from what should have been a fairly consistent supply.
It was on this project where we really needed to understand the strength of the supply that was well beyond just 300, 400, or 500 gpm into the system. But why?
Why does it matter if we flow 500 gpm or 1,000 gpm when doing a flow test?
One perspective - and one answer to this - is confidence in the data. We gain more confidence in our test results with the greater amount of water we flow. Here's a video we put together that explains this perspective a little better:
Hope you have a great week!
What is a Mixed-Use Building?
This week we're featuring a free preview of one of our instructor-led videos on the MeyerFire University platform. Chris Campbell, a Fire Protection Engineer & Writer at the BuildingCode.Blog joins us to discuss what is a "Mixed-Use", or more appropriately, a "Mixed-Occupancy" building under the International Building Code.
Click here, or the video above, to check out what exactly is a Mixed-Use Building.
Hope you have a great week!
Our Challenge and Focus for 2022
What a year was 2021.
What started as hope for a 'return to normal' felt more like a ramped-up version of 2020.
I'm not even going to pretend I'm qualified to speak on world events, but I can say with certainty that our fire protection industry is seeing a great degree of change, and it is happening quickly. Many consultants and contractors I speak with talk about a need for talent - and I only see that growing once the 'Great Resignation' takes place in the coming 2-5 years and many of the remaining Baby Boomers see their retirement come to fruition.
I've also seen a rapid adaptation to new technology, and somewhat of a willingness to consider new approaches to where and how we work that I wouldn't have thought possible just a few years ago. Remote work is here, and it doesn't look like it's going anywhere anytime soon.
What does that mean for collaborative-intensive environments like design? What does that mean for our training processes that have relied on one-on-one, side-by-side mentoring for so long? What if we can't just overhear the conversations from the experienced mentor in the next cube?
The truth is our industry needs to recruit, empower, and develop new talent.
If we don't, I could see a lot of overburdened professionals, sloppy and under-baked work, and a real stress on jurisdictional authorities to police designs, installations, and building upkeep.
However, I do think we are up for the challenge.
I think we, as an industry, are recognizing that major change needs to happen and we need to support our people to make great work happen in a compressed timeframe like we've never had to do before.
That's the big focus for us at MeyerFire this year.
How do we empower and radically support the professionals in our industry - to keep up with the increasing demand - actually improve quality - and develop new talent all at the same time?
It is possible.
Just three examples on how we're working on this include the new MeyerFire University, which is constantly expanding with new content. I'm helping support with NFSA's 3rd Edition of the Layout, Detail, and Calculation of Fire Sprinkler System book that has long been a staple reference for designers and engineers in suppression, which will soon be expanded with many new visuals. The last I'll just tease - and say there's some great potential for a community-driven work that details how our systems are actually put together. More on that to come in the next few months.
I look forward to working with you and the team in the coming year to help drive the industry in the right direction and empower the pros that make great work happen.
If you have ideas - concepts - questions - need support - I'm always available at email@example.com.
Thanks for being part of the platform, and I hope your new year is off to a great start! We look forward to what's in store around here.
An Updated NFPA 13R & 13D Impact Cheatsheet
We've had an extremely busy fall thus far. We had a soft-rollout of the MeyerFire University platform, which has had very positive feedback and is already over 100 users strong (just a few weeks in)!
If you're interested in learning more, email me at firstname.lastname@example.org and I'd be happy to share more detail or set up a quick demo for your team.
UPDATED NFPA 13R/13D CODE IMPACT CHEETSHEET
A couple of years ago I wrote a couple pieces on when NFPA 13R can be used, and I put together a cheatsheet on the code impacts associated with using NFPA 13R and 13D.
I'm happy to say that we've now updated the cheatsheet with impacts from the 2021 Edition of the IBC. While it may not yet be the adopted building code for your area, it's still important to compare code impacts with the latest version of the building code, so that you're not building a structure today that is already beneath modern building code standards.
Click below to get a copy of the updated cheatsheet:
Thanks & have a great rest of your week!
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Joe Meyer, PE, is a Fire Protection Engineer out of St. Louis, Missouri who writes & develops resources for Fire Protection Professionals. See bio here: About