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(phone rings)

Piping Installation Hotline: “Piping Installation Hotline, how can we help you today?”

Curious Caller: “Yes – I have some high density polyethylene (HDPE) piping that I need to install and I need a lot of guidance.”

Piping Installation Hotline: “I have no idea what you are talking about.”

Curious Caller: “Isn’t this the Piping installation Hotli….”

Piping Installation Hotline: “JUST KIDDING!!!  I like to sprinkle a little humor in our calls – you are in the perfect place for HDPE pipe installation!!”

Curious Caller: “oh……hahahaha…funny.”ct.

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Determining Pipe Diameter

Piping Installation Hotline: “First question – what diameter of HDPE pipe are we talking about?”

Curious Caller: “I have three lines – one is 4-inch, one I have not determined the diameter yet, and the third is 36-inch HDPE pipe.”

Piping Installation Hotline: “Fantastic!  OK. Are you able to install the HDPE pipe by open cut or direct burial – by digging a trench? Or are there obstacles impeding you?”

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Handling Obstacles

Curious Caller: “Obstacles?”

Piping Installation Hotline: “Yes.  Is there a neighborhood or housing development, roadways, railroad tracks, water, or environmentally sensitive areas that you are unable to disrupt with your HDPE pipe installation?”

Curious Caller: “Yes actually – all three jobs in fact would qualify under one or more of those categories.”

Piping Installation Hotline: “That helps – it narrows us down to utilizing trenchless installation.”

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Trenchless Installation Options

Curious Caller: “Ok.  I’ve heard of that – are there multiple options?”

Piping Installation Hotline: “I’m glad you asked.  Yes, there are – let’s approach it this way – are any of these HDPE pipe installations replacing an existing pipeline?”

Curious Caller: “Yes – one will replace a failing ductile iron line.”

Piping Installation Hotline: “Excellent – what is the diameter of the existing line?”

Curious Caller: “It was an 18-inch line, but we haven’t decided what diameter to replace it with.”

Piping Installation Hotline:  “Perfect – this will qualify as a trenchless “rehabilitation” as opposed to installation.  The host pipe has done some of the legwork for you.  That usually reduces the cost of the project.  Within that category, there are a few different options.  Would you like to hear them?”

Curious Caller: “Absolutely, thank you.”

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Trenchless Rehabilitation Methods

Piping Installation Hotline: “The most common means of pipe rehabilitation are:

• Slip lining
• Pipe bursting
• Fold-and-form pipe lining
• Cured-in-place pipe (CIPP).”

Curious Caller: “Wow – I have a lot to learn about HDPE trenchless installation.”

Piping Installation Hotline: “Don’t worry – we have all of the answers you need.”

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Cured-In-Place Pipe (CIPP)

Curious Caller: “Work backward for me – tell me about cured-in-place-pipe.”

Piping Installation Hotline: Cured-in-place pipe (CIPP) is a method that runs a felt lining into a failing pipe and a resin in the felt fabric is then attached to the interior walls of the pipe with a curing element.”

Curious Caller: “What are the advantages or drawbacks of this method?”

Piping Installation Hotline:  “While CIPP can improve flow efficiency and can be executed with reduced manpower, it requires careful monitoring during the curing process and limits maintenance and cleaning options. There are also concerns about the harm that has resulted from chemicals used in the process.”

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Fold-and-Form Pipe Lining

Curious Caller: “OK. Fold and form?”

Piping Installation Hotline: “A similar process to CIPP – fold-and-form pipe lining involves inserting a custom pre-fabricated liner typically made of polyethylene (PE) or polyvinyl chloride (PVC) into the existing pipe and expanding using heat and pressure to adhere to the interior of the pipe.”

Curious Caller: “Similar advantages and disadvantages?”

Piping Installation Hotline: “Well – it keeps the interior diameter of the existing pipe the same, handles bends in the route, and eliminates the need for additional grouting due to zero annular space.  Like HDPE it also provides an environmentally safe option. However, it can only be used for smaller diameter pipes up to 36 inches, and can require more equipment than slip lining.”

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Sliplining

Curious Caller: “Natural segue.”

Piping Installation Hotline: “Yes – thank you.  Sliplining.”

Curious Caller: “I’m intrigued.”

Piping Installation Hotline: “To simplify – sliplining is a method where a new smaller diameter pipe is placed into the host pipe and the annular space between the pipes is sealed and grouted.  The new HDPE line would have an improved flow rate, so you aren’t compromised by using a smaller diameter pipe.”

Curious Caller: “That’s insane.”

Piping Installation Hotline: “In many cases, it is a string of HDPE pipe that has been fused together, but materials like Snap-Tite® and Spirolite® have bell and spigot joints that snap together to form the seal and can be fed through one-at-a-time.”

Curious Caller: “Like Legos for grown-ups?”

Piping Installation Hotline: “I never thought of it like that – kind of.”

Curious Caller: “But a smaller diameter pipe has to be installed?”

Piping Installation Hotline: “Well – not necessarily.  There is also a rehabilitation method known as “compression fit” that installs a line of HDPE that is a greater diameter into the host pipe.”

Curious Caller: “Wait – how does that work?”

Piping Installation Hotline: “That’s where the compression comes in to play.  A dye is set ahead of the installation port, that “compresses” the HDPE pipe to a smaller outer diameter that fits into the host pipe.  Tension is kept on that pipe while it is pulled through the host to retain its size.  When the pull is complete – the tension is released and the pipe expands to fill the host pipe, leaving no annular space.”

Curious Caller: “That is insane.”

Piping Installation Hotline: “I know – RIGHT!!  Most projects fall within the 16-inch through 54-inch range.”

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Pipe Bursting

Curious Caller: “That’s amazing.  Soooo….does pipe bursting involve explosives?”

Piping Installation Hotline: “Oh my NO!  Pipe bursting, as the name suggests, forces entry into the existing pipe material, breaking it and pushing it into the soil while pulling and installing a new HDPE pipe in its place.”

Curious Caller: “That’s much less dangerous.”

Piping Installation Hotline:  “Yes – it is. The process offers the advantage of having a new pipe, with the opportunity to upsize to a larger diameter if the soil conditions allow, giving you the advantages of HDPE – a high flow rate, corrosion resistance, flexibility, leak-free properties and a long-term solution with a stress-life of 100 years.  And you don’t have to dispose of the old pipe.”

Curious Caller: “Are there limitations?”

Piping Installation Hotline: “Pipe bursting is useful in certain situations but it is typically used on smaller diameter pipe and shorter distances.  In addition, non-fracturable host pipes such as ductile iron are more challenging to replace. This is because the material doesn’t fracture and is often called ‘pipe splitting’. The process requires a splitting tool (glorified pizza cutter) to first cut the ductile iron. Next, the expander pushes the ductile iron further open as the new HDPE pipe is installed.”

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Trenchless Installation Methods

Piping Installation Hotline: “Ooooh – pizza sounds awesome.”

Curious Caller: “Actually it does.”

Piping Installation Hotline: “Sorry – I get sidetracked when people mention food.”

Curious Caller: “Same.”

Piping Installation Hotline: “Ok – gotta focus.  There are a few other rehabilitation methods that can be used, but the ones we discussed are the most common and effective.”

Curious Caller: “Awesome.  “So what are the non-rehabilitation trenchless options?”

Piping Installation Hotline: “Yes – trenchless “installation” methods.  These methods for the installation of pipelines and cables below the ground with minimal excavation include:

• Tunneling
• Micro tunneling (MTM)
• Pipe ramming (PR)
• Pipe jacking (PJ)
• Moling
• Horizontal auger boring (HAB–
• Horizontal directional drilling (HDD) also known as directional boring.”

Curious Caller: “I dig it.”

Piping Installation Hotline: “HAHAHHAA – now you’re the funny one.”

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Horizontal Directional Drilling (HDD)

Curious Caller: “Well….I….”

Piping Installation Hotline: “The Cliffs Notes version of HDD is this:  you have a pilot hole, your fused length of HDPE pipe, a drilling head, back reamers, and a pullback head….”

Curious Caller: “Sounds like positions for a team in a new made-up sport.”

Piping Installation Hotline: “Ha! A pilot hole is drilled by the drilling head from point A to point B, in some cases a back reamer expands the size of the hole, the pullback head is attached to the length of pipe and it is pulled from point B to point A.  Easy peasy lemon squeezy.”

Curious Caller: “There you go with food again.”

Piping Installation Hotline: “Yeah – sorry.”

Curious Caller: “Would this work for my 4-inch or 36-inch lines?”

Piping Installation Hotline: “Oh yes!  Both.  ISCO installed a 54-inch pipe with HDD in Miami on a sanitary force main.  It was 3,000 feet long!”

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Minimal Disruption with HDD

Curious Caller: “Whoah!! And IN Miami – like neighborhoods and houses and stuff?”

Piping Installation Hotline:  “Yep.  Minimal disruption – and site restoration is limited to drill entry and exit points, unlike open trench installation where you’ll spend lots of time, money and resources restoring the environment.”

Curious Caller: “That sounds like a great option.  And it saves money and time?  Win-win-win.”

Piping Installation Hotline: “Bingo!”

Curious Caller: “You have been SO helpful today.  You remind me of this really cool blogger that I know.”

Piping Installation Hotline: “Gee thanks – that’s what we are here for.  If you need more information feel free to call the good folks at ISCO – they have ALL of the answers and solutions for HDPE pipe trenchless installation methods. Anything else I can help you with?”

Curious Caller: ” I don’t think so – unless you know where the best pizza in town is.  I’m hungry.”

Piping Installation Hotline: “Well….as a matter of fact…..”

Interested to find out how we can help create efficiency, cost savings, and minimize disruption on your piping project, then get in touch with one of our experts who can provide you with guidance on trenchless installation solutions suitable for your application.