Yes. In many mining and industrial applications, HDPE pipe has been installed above ground and has provided and continues to provide excellent service after 15 to 25 years (North America), with the potential to remain in service for many more years.

The upper limit temperature for pressure service is 140 degrees F. In structural pipe, gravity flow applications in stable soils; the upper thermal limit is considered to be in the range of 160F for long-term exposure; and up to 180 F for short-term intermittent exposure. The low temperature limit is usually regarded as minus 130 degrees F (see next question). Cold temperatures do not adversely affect HDPE in static applications. Water within the pipe may freeze solid without damaging the pipe.

KWH offers HDPE fittings in standard configurations, including: straight and reducing tees, elbows, crosses, concentric and eccentric reducers, flanges, mechanical-joint adaptors, outlet branch-saddles, etc. These can be fused directly to the HDPE pipe. Custom fittings are also available upon request.

Sclairpipe and WehoGas are available either in coils or straight lengths. Coils are normally available for small diameter pipe (6 inch and smaller). Weholite is manufactured only in straight lengths and it is available in custom lengths up to 60' long.

THE US EPA expects 100-year service life from HDPE landfill liners. Buried solid wall or profile wall HDPE pipe should last at least as long. HDPE pressure pipe was first used in water service over 50 years ago. Current accelerated testing methods predict that today's HDPE pressure pipes will last much longer than 50 years. Everything points to a service life of at least 100 years in a properly designed and installed HDPE pipe system.

Yes, HDPE pipe has a specific gravity of about 0.95 so it will float. For underwater, anchored pipeline installations, it is important to specify the proper weights and spacing of the weights. Screw-anchors are a practical alternative. Whenever possible, an underwater pipeline should be installed in a trench with protective crushed rock cover. (See KWH's 'Marine Installation" brochure and/or the Marine Installation chapter on PPI Handbook).

Yes! It is necessary to know the diameters to be connected and to define whether the pipes to be connected together have a socket or otherwise.

Unfortunately, most plumbing stores don't carry HDPE - often times the store employees have never even heard of it. Usually it can only be found at large industrial plumbing supply places. You can also purchased pre-cut, plugged pieces of HDPE pipe from Pyrogear.net, which specializes in making mortars for fireworks.

Definitive Sealing: by welding the Valsir sealing cover (art. 342). Non-definitive sealing: solution A: by welding the Valsir sealing cap (art. 340). Solution B: by welding the Valsir collar (art. 347) then, using the Valsir free flange (art. .45), the corresponding set of Valsir bolts (art. 341), the Valsir sealing gasket (art. 343) and the Valsir blind flange (art. 346).

If the proper amount of ultraviolet stabilizer has been added to the colored pipe resin, non-black pipe can last several years in outdoor storage. Non-black pipe is not recommended for permanent outdoor use. Black PE pipe has been stabilized with carbon black, which is the most effective ultraviolet stabilizer. PE pipe with carbon black UV stabilization (the normal black PE pipe), may be used indefinitely outdoors.

A No. All objects expand and contract. As with all materials, expansion and contraction must be taken into consideration when designing a HDPE piping system. The resistance to movement provided by friction between the pipe and its' embedment is usually sufficient to prevent thermal expansion and contraction. No. When HDPE pipe is buried, the temperature of the system becomes much more stable than when it was above ground. Therefore it will exhibit far less dimensional change.

Yes, HDPE pipe is suitable for direct burial under railroads with just 4-5 feet of cover. An engineering burial analysis is recommended. Due to the prior poor experience with "brittle" PVC (plastic) pipe, most railway specifications require that all pipe crossings must be encased in steel pipe. Based on a structural evaluation, impact tolerant HDPE pipe does not require a steel casing, but jurisdictional requirements will usually prevail.

HDPE pipe can be cold or hot (under pressure) tapped using saddle fusion tapping tees, electro-fusion tapping tees, Fuse-A-Corps, and branch-saddles which are readily available in the industry.

Most other companies sub-contract out their playset installations, whereas at King of Swings all installers are year-round, full-time employees. To successfully install playsets in-ground, a learning curve or training period is necessary. Companies that sub-contract out their installations are not able to afford such a level of expertise. Furthermore, if redwood or cedar is the only type of wood offered, in-ground installation is simply not possible.

For non-pressure 'drainage' applications, flexible rubber couplings have been used for decades with success. These flexible couplings are made for joining all types of gravity flow drainage pipe, including transitions from one type or size of pipe to another. For pressure applications and low-pressure sewer applications, HDPE transition fittings, HDPE mechanical-joint adapters, Gasket-joint adaptors, HDPE flanges, and standard metal couplings with internal stiffeners are recommended.

The inside surface of HDPE is extremely smooth and has a very low long-term design coefficient of friction. The roughness co-efficient to use with Ductile Iron pipe recognizes the likelihood that the ID roughness will degrade over time. The smooth bore of HDPE pipe is maintained throughout its service life. It is often possible to use a polyethylene pipe with a smaller inside diameter than the comparably sized ductile iron pipe, and still achieve an equal or greater flow.

No. HDPE and PVC pipelines are installed using the same standard backfill procedures. Both are thermoplastic materials, requiring the same considerations for proper embedment and backfill. The popular ASTM standard D2321 applies to both pipe materials.

For Sclairpipe and WehoGas the rule of thumb is to use a minimum bending radius of 50 times the nominal diameter of the pipe. Weholite can be bent to a minimum bending radius of 200 times the nominal diameter.

UNI EN 1519-1 standards indicate 95°C, whereas the softening point, namely the temperature which causes the piece to deform corresponds to 125°C. Therefore, even temperature peaks exceeding 95°C do not create problems.

The CSA standard allows only high-density polyethylene pipe, with the three most common diameters being 0.75", 1.0" and 1.25". Sections of pipe are heat fused and many suppliers offer a warranty of 25 years. The resin in this pipe is the same used in the pipe used to transport natural gas. This plastic does not degrade under sunlight and is warranteed not to fail. Most units include all pumps and controls, but it may be the responsibility of the contract to obtain some individual components.

Casing may not be needed for the entire depth of the well. When drilling in the rock formations in Eastern Pennsylvania generally the casing must be installed ten feet into bedrock. Softer formations may require additional lengths of casing.

Sensors with a 1" transducer should be installed in 2" stand-pipes. Sensors with a 2" transducer should be installed in 3" stand-pipes. Click to view stand pipe installation tech-tip.

SCLAIRPIPE is the KWH Pipe brand name for solid wall black HDPE pipe, used in the municipal water supply, sewage force mains, pressure water systems, and marine intakes/outfalls. SCLAIRPIPE is manufactured from premium PE3408 resins under a very rigorous set of QC procedures. WEHOLITE is the KWH Pipe brand name for large diameter lightweight HDPE pipe. Weholite is manufactured using a structured wall process in a variety of diameters and Ring Stiffness Constants.

Yes. In general terms, with adequate particulate suspension, HDPE pipe has an extremely high resistance to abrasion from slurries. In some applications, HDPE pipe has outlasted steel pipe by as much as 4 to 1 for a given situation.

HDPE pipe is normally joined by heat fusion. Butt fusion, socket fusion, sidewall fusion and electro-fusion are all heat fusion methods that create a leak free joint stronger than the pipe itself. The butt-fusion procedure is most frequently used joining procedure. In this process the pipe's mating ends are aligned and heated with standard tools until the surfaces have become molten.

Yes. Mechanical joint adapters fused to HDPE pipe are available as standard products. These joints are fully restrained.

MJ adaptors or Flange adaptors can be welded to PE pipe. These are then bolted to the other pipe using standard MJ assemblies or flange assemblies. MJ adaptor joints and flanges joints are fully restrained just like fusion-welded joints, so no thrust restraint is required. However if the joints in the matching pipe are not fully restrained (bell and gasket), thrust restraint measures are required at the transition.

Scratches or cuts to a maximum depth of 10% of the Sclairpipe pipe wall are acceptable. The depth of the cut or scratch is measured from the pipe's original OD surface to the valley of the indentation.

While grouting is not required for every application, generally it is recommended that it be done. Grouting the entire annular space is good practice. It generally represents only 3% to 5% of the overall project cost. The annular space must be grouted when the condition of the existing pipe no longer permits it to support soil loads or live loads.

HDPE pipe is a leak free system when heat fused together. As a "zero" leak-rate pipeline, there is no "specification" for leak detection. However, large leaks are easily detected as water quickly reaches the surface. One of the most promising techniques to find smaller leaks is the audio technique, which listens for the sound emitted as the fluid flows irregularly through an unplanned opening in any pipe.