by Greg Mitchell
As a new season begins, it wont be long before the telephone starts ringing. Clients and potential clients will be calling to get their irrigation systems turned on after the winter months, and also checked for any problems. Theyll want to know that their system is working properly.
Repairing an irrigation system is not very difficult, if you have the know-how. We could not do justice to this subject with just one article, so well divide it into a number of articles. In this issue, well address pipe repair.
While some may consider pipe repair to be one of the less technical aspects of irrigation repairs, it too, requires thoughtful execution. If theres a break in one PVC line, its generally easy to repair.
However, repairing piping in an irrigation system can be complicated by several factors. For example, often two, three, or more pipes are crowded together in a narrow trench. Control wiring may share that limited space as well. Frequently, the PVC pipe is snaked and twisted in the trench in such a way that the top pipe at this location may be in the middle, side by side, or even on the bottom just a few feet down the line. In other words, this simple task of pipe repair . . . may not always be so simple!
Practicing a planned, sequential procedure is always more efficient and professional than a haphazard seat-of-the-pants approach. Jeff Kelleher, of James River Irrigation, Richmond, Virginia, sums it up by saying, Keeping the right equipment on the service truck . . . the fittings, the solvent, the glue, and all the necessary tools required to do the job, is key to a secure and permanent fix.
Proper excavation is essential when performing pipe repairs. At first it seems that such a basic and
simple task as digging is hardly worth discussing. However, damage caused by reckless shovel work will often complicate the repair, or even surpass the seriousness of the initial problem. First investigate . . . probe, and carefully excavate. Commit the minimal amount of time and effort required to positively identify the exact leak source. Take notice of adjacent pipes, wires or other components. Determine your plan of action. Once you have a plan . . . DIG A BIG HOLE!
When making excavations in established landscapes, be aware of the impact your work will have on the appearance of the property. Clients are appreciative of, and impressed by, considerate excavation, backfill, and clean-up. Carefully remove and replace sod, mulch, or greenery and use a tarp for the excavated soil. If you find that you need to expand your excavation, you can simply drag the piles out of your way.
Excavate around and under the piping. Create a large enough workspace in which to facilitate the repair. For some reason, many of us try to keep the area of soil that we have to excavate as small as possible. We should keep in mind that there needs to be enough room for pipecutters and adequate space to operate them; room for a saw and space to make sawstrokes; and so on. The excavation may need to be expanded to allow for more movement of pipes, so that they can be gently pried, wedged, and propped apart for cutting and gluing. A sump area should be created underneath the repair site. This sump allows pipes to drain without the risk of possible contamination. Debris floating into open pipes can cause problems throughout the system, especially if it were to float into the mainline. The sump can be pumped or bailed out prior to making the repair.
Pipes should be clean and dry before solvent welding (gluing). Care should be taken not to over-apply primer. If too much primer is used, it can pool inside the thin pipe wall, weakening it, and degrading its integrity. Also remember that cold temperatures will cause PVC pipe to become brittle and difficult to cut without shattering.
With very crowded piping, its often necessary to cut adjacent pipes in order to gain access to and repair the damaged one. In such cases, always mark and match these pipes for proper reconnection. Also, in certain situations, adjacent pipes must be reconfigured, or offset with 45° elbows in order to gain necessary clearance around a repaired pipe.
Fortunately, in recent years, innovative manufacturers have begun producing products specifically designed for repair work. Probably the most widely used such product is the telescopic-type coupling. Known by a variety of brand-names, this ingenious item utilizes an internal o-ring and pressure to seal tightly, while providing full penetration of all glue-joint sockets. Prior to this innovation, repairmen resorted to bowing pipe, stressing it dangerously, and settling for only a fraction of proper socket penetration.
According to Ken Carpenter, of Ken Carpenter Sprinkler Repair, Carrollton, Texas, Most telescopic fittings must be fully extended to seal securely. Failure to do so creates a weak joint, and there is a tendency for a partially extended fitting to bow under pressure.
Full extension is required on some other brands of slip-fittings because they are un-rated for pressure if they are not fully extended, stated Ron Modugno, sales manager of King Brothers Industries. However, on our new PVC telescope repair couplings, they will operate as expansion joints if not fully extended. They come in sizes up to six inches.
Other repair-oriented products have begun to emerge on the irrigation market as well. These include flexible, glueable PVC pipe, and specialty O-ringless repair fittings. Dawn Industries is marketing its Kwik-Repair for tees, elbows, and couplings.
Epoxy, resin, and fiberglass patches and wraps can provide temporary, stop-gap or emergency repairs. Some of these patch and wrap repair kit products even claim to work on pipe thats leaking and under pressure. Indumar Products markets its Stop-It Pipe Repair System for this use. It is a pre-coated, knitted fiberglass containing a water-activated urethane resin. Christys Slick-Wrap and Neptune Researchs Syntho-Shield pipe repair kits work in much the same way. They can be ideal for effecting secure repairs quickly with minimal excavation.
Applying these type of products to crowded piping could be difficult. Christys offers an alternative pipe repair product to use where traditional products cannot be used. Christys Fastfix is a hand-kneadable steel-reinforced 2-part epoxy putty. After proper mixing, it molds like clay and can be applied to repair metal or plastic pipe.
Compression-type couplings (with rubber gaskets) are very effective when properly installed. That is, with a minimal gap between the ends of the pipe to be joined. However, compression fittings can be too problematic when dealing with crowded piping. Some hot glues claim to join pipe securely, even when applied under water, and rubber/stainless steel clamps have been available for years.
Poly pipe presents some different challenges than PVC, and therefore requires some altered strategies for repair as well. It is connected with barbed insert fittings, which are secured with crimp or screw clamps. One obvious advantage from the repair standpoint is that poly pipe is much more flexible than PVC. This increased flexibility allows for bowing the pipe without stressing it, or risking its integrity.
Generally speaking, poly pipe is easier to repair than PVC, especially in diameters of less than 1½ inches, states Eric Ofstedahl, Horticulture Services Co., Scandia, Minnesota. The composition of the poly material leaves it more resilient, flexible, and freeze resistant in colder climates.
I have also used the extra flexibility to reconnect mis-aligned PVC pipes in the past, claims Ofstedahl. Special spigot X barb fittings will adapt PVC to poly for this type of application. One downside to poly is that it is somewhat more expensive than PVC. Savings on glue, primer and labor may offset that expense, however.
Through creative use of innovative products, and utilization of proven techniques and procedures, irrigation pipe repairs can be accomplished in a routine and professional manner. But to say that it is simple or easy would be less than accurate. Armed with knowledge, training, and experience, a repair technician can continue to develop and refine his or her skills and to raise the level of professionalism within the industry.
As properties age, repairs will be required. A fresh coat of paint periodically perks up the building. Trimming the shrubs and trees give the property a more manicured look and sooner or later, the irrigation system will need some repairs. In the past year or so, a new organization, Affiliation of Landscape Irrigation Repair Technicians (ALIRT) was formed to provide its members with a network of similarly engaged individuals. As a common interest group within the Irrigation Association, ALIRT addresses concerns and issues unique to those irrigation professionals who focus on repair and maintenance.