Graphite India Limited are the pioneers in the field of manufacturing of large diameter Glass fiber Reinforced Plastic ( GRP ) pipes by continuous process in India. This technology, is the outcome of many years of extensive research & development of M/s Owen’s Corning, USA – world leaders in glass fiber and allied products. Now, these world class “Everflow” G R P pipes are manufactured in our plant at Gonde, Nashik. The composite laminate is a combination of glass fiber, unsaturated polyester resin and fillers. 

The Continuously Advancing Mandrel Filament Winding Machine is a state-of-art-technology. It has a Computer Aided Design and Manufacturing control facility and a built-in curing device. This ensure the optimum production of GRP pipes of uniform high quality.

Outstanding Characteristic

• Corrosion Resistant : No coating, gunniting or mortar lining required for longer life.
• High Strength-to-Weight Ratio : Better than Steel / C.I. Pipes.
• Light Weight : 1/5th of steel, 1/10 of PSC, ease in handling, faster installation, Laying in rough terrain-easier.
• Smooth Surface : Better hydraulic properties, less power and lower pump cost. Hazen Williams Coefficient-C-150 Manning “n” 0.01.
• Longer Lengths :Faster installation, minimum joints.
• Excellent Joints : No exfiltration or infiltration problems.

Quality Assurance

GRP pipes manufactured at GIL meet the International and National specifications like ASTM-3517 / AWWA C-950, IS 12709 and IS 14402. To ensure quality product, we have in-house manufacturing of resins. Our quality control begins with the raw materials. Each raw material is tested individually before being taken up for resin production. On-line testing at main plant ensures quality of resin. Fiberglass and other ingredients are tested as per specifications before being taken up for production. Further due to on-line Computer Aided Manufacturing in our continuously advancing mandrel filament winding machine, thickness and composition are monitored and controlled. Each pipe so produced is physically inspected and hydro tested. Samples drawn from each batch are tested chemically and physically for their soundness. Only after it passes all the tests, it earns the name ‘Everflow’.

Stiffness

Everflow GRP pipe is available in four stiffness classes. Selection of a proper class depends on the type of installation, overburden above the crown of the pipe, and the native soil condition.

Hydraulic Efficiency

As a result of extremely smooth interior surface of the Everflow GRP pipe, Hazen Williams Coefficient as high as 150 for pressure flow and a Manning “n” 0.010 for gravity flow are used, thus providing high flow capacity. Since Everflow pipes do not tuberculate and maintain its original surface smoothness, its high flow capacity contributes considerably to saving in capital cost pump and energy over the project life.

Surge Pressure

Due to its inherent characteristics, Wave celerity value of Everflow pipe is lower than conventional pipes. Thus water hammer in the Everflow GRP pipes is less. Moreover, since GRP pipes can withstand pressure up to 1.4 times of its pressure class in case of surge, which is hither than conventional pipes, it is a better choice than others to minimize risk of pipes, bursting due to water hammer.

Maintenance

Everflow GRP pipe can be repaired at site easily without any necessity of heavy equipments. In the event of damage or crack, it can be repaired by building up the GRP layer by hand lay-up. When the crack is such that the hand lay-up is required over a large portion, it is advised to cut that section and replace it with a piece only 5cm smaller than the original. Joint both the ends by means of Mechanical couplings, or Butt strap joint.

Lengths

The standard length of Everflow pipe is 6 and 12 meters. I can also be supplied in other lengths up to 12 meters for special orders.