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Irrigation Pipe Repair

...Finding...Repairing...Replacing

| Pipe & Fittings
The voicemails you hear when you arrive at your office in the morning may vary, but the message is the same....

“Hi. There’s a big wet spot in the middle of my lawn this morning that wasn’t there yesterday. Can you come take a look at it?” “Hello. There’s water bubbling out of my sprinkler system, where it shouldn’t be bubbling. Can you come on out?” In these cases, the customer is dealing with an irrigation leak or leaks that you can make right with relative ease. In fact, developing leak-fixing expertise can even be a profit center for you. After all, leaks can develop long after a system is installed, or after the installer has gone out of business.

The place to begin is to identify the cause and location of the leak. Sometimes it’s staring you in the face; other times the customer is alerted to the leak only by an unexpected increase in his water bill.

Leaks can arise from many causes, mostly man-made, says Bryan Juwig, director of sales at LASCO Fittings in Brownsville, Tennessee. While it is possible that a section of pipe is defective, the most common reason for a leak is generally a poor glue joint.

“I also see overtightening of female-threaded fittings, and the misapplication of female-threaded fittings that cause ‘hoop stress’ on a metallic joint. There can also be problems with water hammer, with over-cycling or the buildup of air in the line.”

Pipe distributor Tom Stroh of Stroh Sales in Evans, Colorado, agrees that most of the leaks he sees are caused either by a goof-up in installation, or by damage caused by a shovel, spade, or hoe going into the ground where it shouldn’t be going.

When the voicemail comes in, though, the first order of business is to get the leak under control.

That’s when you need to be an irrigation Sherlock Holmes. Hopefully, you’ve got a map (as built) of the installation plan, so you can walk the route of the piping. Even if you don’t, be on the lookout for changes in soil texture. Soft, spongy soil can alert you to a leak below.

One overlooked method for leak detection is the so-called prod rod—a long screwdriver on the end of a pole—with a ballbearing attached to the business end of the screwdriver so that contact with a pipe won’t puncture it. With the prod rod, you “feel” the difference between “normal” earth and earth that’s been saturated by the leak.

Complicated installations with multiple leaks can be accessed via trenchless acoustic leak detection. These systems are often worked by outside engineering companies and use non-invasive sound waves to detect leaks.

Once the leak or leaks have been identified, it’s time to repair them. With conventional PVC pipes, dig down with a shovel or spade, being careful to retain any sod you’ve removed so that you can replace it after the job is completed. Once the leaking pipe is exposed, you’ll be able to determine your next steps. Will you need to pump out standing water to do your work, or can you simply turn off the water flow? How bad is the leak? Is it patchable, or must you cut and replace?

Patch technology for PVC has improved in recent years with products such as Christy Enterprises’ Slick Wrap, and Indumar Products STOP IT. These are fiberglass wraps that are either embedded with a water-activated polyurethane resin or which go over a “Fix It Stik.” Once the leak site is determined and the pipe depressurized, you’d wrap the pipe like an ace bandage, using water to activate the resin. The wraps harden quickly, forming a waterproof seal.

To patch a pipe, you need to be able to get the wrap all the way around. In some cases, that might be simple. In others, it requires far more digging than you’d want. In those cases, cut-and-replace is a better option.

While the process is straightforward, it’s easy to make mistakes that will cause the leak to reoccur, or create other problems within the irrigation system. One of the biggest problems, says longtime irrigation designer, consultant, and landscape architect David Wickham, of David Wickham & Associates in Lake Mary, Florida, is to maintain the same water pressure that caused the leak in the first place.

“When water pressure gets too high, 90 degree elbows and tees suffer from—the term isn’t polite, but it’s what we all use— crotch rot on the inside curve of the turn,” Wickham explains. It’s very much like stream erosion, where flood water rushing around a bend tends to erode the bank of the inside part of the river bend.

“One of the ways to make sure that you don’t have to come back and do the repair all over again, or get called back to the same project for a different repair, is not to overpressurize the system,” Wickham warns.

Similarly, Wickham believes that in many cases, too many repair people and irrigation contractors bury irrigation lines too shallowly. Burying too shallowly is another part of the repair process that can bring you back out to the jobsite to redo the work you’ve already done.

“Think about an irrigation pipe buried six inches down, somewhere near a driveway. What if the driver goofs, cuts off the corner of the driveway, and runs over the pipe? What if something heavy gets placed on the lawn directly over the pipe? That’s a lot of pressure on the pipe. A foot of earth between the object and the pipe is better than six inches. No sense in doing a repair that has to be done over again,” Wickham says.

Another reason to finish off your repair by burying pipes deeply is the effect of temperature fluctuations on the PVC itself. Unlike galvanized steel or copper, PVC is reactive to temperature. Kevin Rost, president of Dura Plastic Products, Beaumont, California, stresses that the expansion, contraction, and dimensional change of PVC pipe must be taken into account in the design, installation, and repair of piping systems.

All pipe materials expand and contract with changes in temperature and these changes must be considered when making repairs. By some accounts, a 1,000 foot pipeline installed in the heat of mid-summer could shrink 20 inches if the soil cooled to 40 degrees in winter.

Rost says this has implications in the repair business. “When you cut out a section of damaged pipe in order to replace it with a coupling, you don’t want to pull it too tight, because it could contract further when the weather turns cold. You should always allow a little slack in the pipe. We’ve got a new flexible PVC repair coupling that can help with that.”

Mark Dupell, of Mark Irrigation and More in Edmonds, Oklahoma, says that one of the most common errors he’s seen in the field, and which results in his having to come in and redo work that others have done, is that repair people don’t blow out a line before making a repair, or make sure that the lines are clean before starting work.

“When there’s a break in a pipe, whether a crack or a hole, each on-and-off cycle siphons dirt into the system. Once I determine where a leak is, I’ll go to the furthest heads on the same line and remove them, so that I can blow out the vast majority of debris in the line.”

Irrigation industry veteran Bill Hagen of Bill Hagen Associates in Altamonte Springs, Florida, stresses the importance of glue and primer. Even with the advent of no-primer-needed glues, Hagen still tends to use both primer and glue in his repairs, especially on mainline repairs. With repairs of larger lines, he uses either gray or white cement, despite their slower drying times. He likes the gap-filling qualities of these cements for large lines.

Hagen also offers a money-saving tip for repairing threaded fittings. “Sometimes, threaded fittings deteriorate to where the threads aren’t right anymore. I often suggest to the customer that we simply try to glue the male adapter into the end where the threads are failing. The way I see it, the alternative would be to cut it out and fix it.”

“If the glue holds, it can save the customer maybe a couple of hundred dollars, depending on the size and the complexity. If it doesn’t hold, we’ll just come back and do the replacement.”

Finally, a word about the “other” common piping. While the irrigation market is dominated by PVC, there are still a reasonable number of irrigation installations that employ flexible polyethylene pipe, called “poly” or “black pipe.” Poly pipe typically handles lower pound-per-square-inch water pressures than PVC, but has the advantage of being customizable by the manufacturer, who can adjust the resin mix of the pipe for particular uses and installations.

“Fixing poly is easy,” says Stroh, a 34year veteran of the irrigation business. “Poly failures typically happen because someone puts a shovel through the pipe or an animal does some chewing. You simply cut out the offending piece of poly, and then slide a hard coupling into the open ends, extending the coupling several inches into the open hole. Then, use a clamp to tighten the poly around the coupling.”

Some contractors say that a squirt of dish soap or WD-40 on the coupling can make the coupling slide in more easily.

Whether PVC or poly, nothing lasts forever. So when you hear that message on your answering machine, think of it as a way to establish (or reestablish) a connection with your customers, at the same time building up your irrigation system repair business, and getting some new business leads. It’s dirty, muddy work, but there’s ample reward at the other end of your shovel.

 
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