Breaking Free from Tradition

People can be resistant to change. When you find a comfort zone with a product or a manner of doing things – you stick with it. But sometimes technology moves you forward with a better way of doing things.

Large diameter legacy piping systems like concrete have been a security blanket in numerous applications, that municipalities, contractors and engineers have had a Linus-like relationship with due to the familiarity.

Once upon a time they were the only solution, and in some cases, they remain the most sensible solution.

But more and more, the use of high-density polyethylene (HDPE) pipe in large diameter applications give you the comfort you seek and more.

That’s right – HDPE – a bigger, warmer and fuzzier security blanket.

The Benefits of HDPE over RCP

When comparing reinforced concrete (RCP) and HDPE in large pipe applications, the crossover end markets include municipal water mains, storm sewers, sanitary sewers.

Beginning with size, RCP is found in diameters between 12″ and 144″. Depending on the application, solid wall HDPE can be used with diameters from 3/4″ to 138″. If you have a low pressure or a gravity system, a lighter weight profile wall HDPE pipe known as Spirolite™ is produced in even larger diameters – up to 157 inches.

I know that large-diameter pipe is the subject, but it is worth noting that an HDPE system can be utilized from the largest diameter genesis of the pipe to the smallest branch, where RCP only drops to 12 inches. With HDPE you have the opportunity to utilize one material from source to end user.

Sticks of RCP pipe are typically less than 8 feet long, whereas HDPE starts at 10-foot sticks to up to over 40 feet in length. That means fewer joints and a quicker installation process.

With that in mind, the sheer weight of RCP compared to HDPE makes shipping and transport of RCP exponentially more expensive than HDPE. RCP is 1,114 pounds per linear foot with 54-inch pipe. HDPE weighs 222.64 pounds per linear foot.

Once the pipe is on site, before the install, there are two factors to consider when using these two materials. One – there are concerns when off-loading the RCP, as it is susceptible to breaking. Additional costs can be added with the equipment and expertise required as well as potential replacement of damaged pipe.

HDPE is durable enough that there is actual documentation of pipe being carried in a tornado a substantial distance without damage.

The second consideration is the equipment required to move the pipe in the event that the job site is confined and requires a staging area. This goes back to the weight comparison. While large diameter HDPE is heavy, as we referenced above, it is far lighter and manageable than RCP.

That same theme carries into the installation. HDPE allows more options than RCP with the installation process, as trenchless technology minimizes the impact on the site, as does the ability to fuse the pipe above ground before lowering into a trench. It can also be installed more quickly, especially with the large diameter Spirolite and the bell and spigot joining system.

In addition to the transport and installation concerns, the rigid nature of RCP makes changing direction – however so slightly – an added challenge that requires joints and fittings, adding to the cost and installation time. The flexible nature of HDPE piping, even in large pipe can be bent to a radius 20 to 25 times the diameter of the pipe depending on the diameter and wall thickness – or dimension ratio (DR).

While that may not allow an immediate right turn with large diameter pipe, the ability to contend with twists and turns without fittings is highly favorable to zero bend radius.

And if you need that hard 90 – a simple elbow and fusion in the field can provide a bend that would make a capital “L” proud.

In the simplest terms, RCP can’t keep up with the flexibility – when it comes to flexibility – of HDPE.

From Installation to Longevity: Why HDPE Stands Out

Once the pipe is in the ground – more factors come into play.

We begin with leaks.

As shocking as it may sound, other piping solutions have some standards that are agreed upon because some leakage is allowable if not expected.

Let me restate that.

Because of the quality of the joints and pipe – leaking is expected. And that’s ok.

If I told you that you can choose between having two liters of soda in your bottle, or between five and fifteen percent less, what would you choose?

With water insecurity, especially in the west, water is life.

And money.

Nobody likes to lose money.

Leaks are unacceptable. And properly installed HDPE will not leak. With the potential for cracks, chips, and non-monolithic joints, RCP…..?(shaking the palm face down with the ehhhhhhh sound). How do you feel about your high-tech fiber optics or other wiring being shielded as conduit by something that might leak?

If you live in an area prone to seismic activity, HDPE is equipped to literally roll with the punches, while RCP could be vulnerable to shifting soils. In addition, the smooth interior of HDPE pipe is proven to have a higher flow-rate than RCP and eliminates residue build-up.

How about the lifespan?

RCP is durable and presents a lifespan expectation 50 percent that of HDPE. In no case should it ever exceed HDPE’s design life.

So, does HDPE.

That is the good news for RCP fans. But it comes with an asterisk.

With the aforementioned leaking expectations, that means there will be inspections, maintenance and/or repair involved which is costly and time-consuming.

HDPE allows you to utilize it in applications that carry acidic or harmful compounds, like mining, as it is resistant to corrosion.

With RCP there are rare circumstances that the steel that reinforces the concrete can corrode and cause spalling. There can also be internal corrosion, abrasion and incrustation in sewer applications as well as external corrosion in hot soils.

The internal problems can be addressed with inserting an HDPE liner.

Wait. What?

They want to put a liner made of HDPE into their own pipe to protect the pipe and the environment?

You could also just use HDPE piping to begin with.

Corrosion resistant, abrasion resistant, freeze/thaw cycle resistant, biological growth resistant, leak-proof HDPE.

If you only need one security blanket, why would you line the inside of the rigid and vulnerable blanket with the flexible worry-free blanket that makes the other blanket better?

You shouldn’t.

For a change, sleep soundly with HDPE.