Natural gas steel pipeline protection is an important part of your pipeline installation and maintenance program.
Natural gas steel pipeline protection is an important part of your pipeline installation and maintenance program. Steel pipes are generally larger in diameter, transport gas and products at high pressures, and account for more than a quarter million miles of our nation’s current pipeline infrastructure. While steel pipe is strong and long-lasting, it is subject to surface damage and corrosion. The National Association of Corrosion Engineers (NACE) recommends a number of different techniques for corrosion control, line monitoring, and maintenance. Over the nearly 45 years we’ve been in business, GROEBNER has developed a supplier network that can provide you with the best corrosion prevention products in the industry.
Separating Pipeline From Corroding Elements – Pipeline Coatings
One level of corrosion protection of pipelines calls for the use of tapes, sleeves, and coatings. For corrosion to occur, metal, water and air must be present. A transmission pipeline, which is made of steel and typically buried in soil, is exposed to water and oxygen throughout its lifecycle. This category of products places a barrier between the steel pipe and the water and oxygen that can create rust / corrosion. Coatings, tapes, and sleeves are applied before the pipe goes into the ground and for repairs of surface and coating damage, after the pipe has been installed.
Chase Corporation offers cold applied tapes that meet NACE standards SP0109 (Cold-Applied Laminate Polymeric Tapes) and ASNI/AWWA C209 (Type II). Tapecoat H35 and H50 is designed for small to medium pipes and can be applied over a wide range of ambient temperatures. These tapes are UV stable, so they can be used on above ground pipelines, as well as underground lines. Tapecoat T-Tape is designed for use around irregular fittings, bends, tees, and other hard-to-coat substrates, on underground pipelines. This highly conformable tape works in areas that might otherwise require a liquid coating.
Wax tapes are another tape solution that is environmentally friendly and simple to apply. Trenton Wax-Tape brand wraps use a blend of microcrystalline waxes and plasticizers, with no fillers. This makes them particularly conformable to irregular fittings and compatible with many types of metal. Trenton #1 is used below grade, while Trenton #2 is for above-ground applications, with resistance to UV light and other environmental exposures.
Some corrosion protection products are designed to protect pipeline from abrasion stresses and scarring from boring and horizontal direction drilling (HDD) installation methods. CSNRI Scar-Guard protects the girth weld coatings, protects the leading edge of the bores, and reduces the need for spot repairs while providing strong, long-term protection. It comes in several length options and is a wider, thicker coating which makes it ideal for larger pipe applications to get the job done faster.
For liquid pipeline coating, epoxies by Chase Corporation’s Tapecoat brand offers several solutions to meet your needs. All Tapecoat’s epoxies meet NACE standards RP0105 and ANSI/AWWA C210. Applications for above-ground pipelines, epoxies that can be used alone or as primer coats for wraps or tapes, fast curing for back-fill within 2-3 hours – Chase’s Tapecoat epoxies give you the best options available.
Speaking of backfilling, some soil conditions (rock and cobble) call for some extra protection for your pipelines as you complete their underground installation. That’s where Sika USA’s Tuff-N-Nuff rockshield shines. Made with virgin PVC material, Tuff-N-Nuff is the best performing guard against rock impingement. Tuff-N-Nuff is formulated to maintain flexibility in extreme cold weather, ensuring that application can be made faster and more safely, no matter what the temperature.
Defending Pipelines from Electrolytic Corrosion – Cathodic Protection
The products we’ve discussed so far are focused on physical protection of the pipeline surfaces. But pipelines can also be damaged and corroded by electrical currents running through the ground or other metal lines located in the vicinity. The electrical currents change the soil conditions to rob electrons from the exposed piping and cause pinpoint corrosion. GROEBNER’s supplier team can also help you obtain this type of pipeline protection.
Magnesium anodes protect steel natural gas pipelines from corrosion by attracting the electro-static charge more readily than the pipeline to which it is attached. The anodes are sacrificial and will corrode, leaving the pipeline intact and undamaged. GROEBNER offers anodes in a variety of configurations to fit your exact application. GROEBNER carries their high potential anodes, with 10’ – 15’ #12 AWG solid copper THN coated lead.
Rectifiers are another way to combat electrolytic corrosion by inducing current onto the pipeline changing the pipe condition and mitigating corrosion. Using either anodes or rectifiers requires the use of isolating products that sectionalize the pipeline and ensure the protection is adequate.
Flanges and flanged joints are typical isolation points on the pipeline. Often meter and regulator stations have metering and monitoring equipment which need to be isolated from other currents. Flange insulation kits use gaskets and non-conductive sleeves and washers to help isolate sections of piping. GPT offers flange insulation kits in a variety of sizes, materials, and ANSI ratings to meet your needs. The variety of new materials makes these insulating kits superior to kits of the past. Their Type E kits use a full-faced gasket that fits the diameter of the flange. Their Type F kits use a smaller ring gasket that fits within the bolt pattern of the flange. You can configure these kits to best suit your needs.
Of course, if you can avoid flanged joints altogether, that simplifies your corrosion preventions. GPT offers you ElectroStop® monolithic isolation joints. These isolating joints are fully assembled in the factory, eliminating the potential errors of field assembly. ElectroStop joints are leak-proof, with no conductivity from one side of the fitting to the other, so there’s no possibility of short circuits. The ElectroStop joints are perfect for sectionalizing the pipeline when utilizing rectifiers. GPT’s ElectroStops are 100% hydrostatically, electrically, and weld tested, making them a maintenance-free, long-lasting solution to stopping electrical current flow. Because they are fully tested, in a lot of installations, the ElecroStop joint is the final connection piece installed after hydrostatic testing.
In roadway or railroad crossing installations, it is required to protect the pipeline from physical stresses and install casing pipe in which the pipeline is installed through the casing. To prevent degrading the cathodic protection systems, the carrier pipe needs to be isolated from the casing pipe. Casing spacers are used to center pipelines in the casings and electrically insulate the pipeline from the carrier pipe. Centering and insulating eliminate potential shorts that could occur between a carrier pipe and casing, degrading the cathodic protection system employed. GPT offers a full line of casing spacers and end seals to center pipe in the casing and seal the ends, to keep debris form filling up the void. Depending on the application, GPT offers lightweight PE spacers, high-temperature casing spacers, and custom steel spacers for the longer insertions or multiple carrier pipes enclosed in the same casing. All spacers offer high abrasion resistance and low coefficient of friction to make installation easy. Likewise, there are a variety of end seals and wall Link-Seals for all applications manufactured by GPT. Using high quality materials and the right casing spacer and seals for the job protects the pipeline against coating damage and shorts and ensures adequate protection for the life of the pipeline.
Monitoring Corrosion on Pipelines
The top level of pipeline protection is proper identification and testing above ground. All cathodic protection systems need monitoring stations that facilitate monitoring and testing on a periodic basis, to ensure the pipelines are receiving adequate protection that fully mitigates the effects of corrosion. Rhino TriView Test Stations offer both the above ground test station, and a 360-degree visible Rhino TriView pipeline marker. The easy access terminals of the test station can be either positioned externally or internally under the cap. Ten feet of wire can also be pre-installed inside the post for even faster installations. Visibility and monitoring equals protection.
Helping You Maintain Your Pipeline Systems
Since our beginning as a single-office company to today as a national firm, family-owned GROEBNER has focused on the importance of helping you, our customers, maintain natural gas infrastructure. The safety of your pipeline systems is of paramount importance to all of us. We can help you determine and obtain the perfect corrosion control and insulation solutions you need. And we can also help you with many other solutions for all the ways you grow and maintain your utilities. You can always reach us with your questions at 800-638-8322 or sales@groebner.com. Let us help you with all your natural gas pipeline needs.