specialised underground fuel piping


NUPI has particular experience in the production of polymer pipes specifically dedicated to oil markets, chemical and petrochemical plants and offers the wisest choice of piping systems and fittings available for underground fuel storage use.

The most common applications for SMARTFLEX pipes and fittings, both in suction and pressure installations, are as follows:
• Road and motorway service stations
• Harbours and marinas
• Fuel distribution in airports
• Fuel storage tanks
• Generator connections to fuel tanks

Forgeweld is proud to be the preferred South African agents and distributors for NUPI products. NUPI SpA of Italy has been a global leader for 35 years in the development and production of High Density Polyethylene (HDPE) thermoplastic piping systems.


Hydrocarbon and corrosion resistant

The SMARTFLEX and SMARTCONTAINMENT systems feature multilayered piping:
an outer casing of High Density Polyethylene (HDPE), with an internal lining of high-performance engineering thermoplastics.

Piping joint components consist of electro-welded fittings manufactured from proprietary materials and technologies that ensure a high level of corrosion resistance and hydrocarbon compatibility unattainable by other fuel pipes on the market.

Many major international petroleum companies approve and use SMARTFLEX and SMARTCONTAINMENT.

SMARTFLEX – Outclassing the rest of the field.

The internal lining of the SMARTFLEX single wall pipe is colour-coded to allow for the correct matching of product and application. SMARTFLEX piping provides exceptional long-term resistance to pressure, is highly resilient and ensures superior chemical resistance to alcohols, solvents, saline, acid and alkaline solutions.

Safe, corrosion-free fittings

The SMARTFLEX system offers a vast range of fittings, including couplers that are electro-welded to be safe, corrosion-free and leakproof, plus spigots, mechanical fittings and entry boots.

With the exception of the mechanical fittings, all items are provided with welding witnesses, which “pop up” as welding proceeds, thus allowing the installer to keep a record of installed fittings.

Proprietary materials and technologies ensure a unique degree of hydrocarbon resistance, placing the SMARTFLEX system way ahead of competitors in its field.

The SMARTFLEX system has been optimised for use in underground applications and for the conveyance of the following fuels:
• Gasoline
• 98 unleaded gasoline
• 95 unleaded gasoline
• 95 unleaded gasoline with 8 to 10% ethanol (SE95-E10)
• Methanol
• Toluene
• Kerosene
• Alcohol fuels
• Diesel fuels
• Aviation fuels
• Diesel oil
• Non-sulphur diesel oil
• Naphtha
• Jet Fuel A

The SMARTFLEX system has succesfully undergone many tests that proved its compatibility with the following new bio fuels:
• Bio diesel
• E85 ethanol



NUPI’s greatest piping innovation yet – quick, easy, effective containment

SMARTCONTAINMENT consists of a high-pressure double-wall piping system – effectively a ‘pipe inside a pipe’, providing for more demanding containment and monitoring requirements. The inner pipe consists of the SMARTFLEX system (described above), running inside a second pipe, similarly constructed from HDPE.

The internal and external pipes are connected by SMARTCONTAINMENTPLUS fittings. These allow a continuous interstice, as well as pressure testing and monitoring using test ports fitted with quick-fit connectors and a pressure medium such as nitrogen.

SMARTCONTAINMENT eliminates the use of costly sumps, which are replaced by small pans located beneath each dispenser. In addition, SMARTCONTAINMENTPLUS fittings make the installer’s job quicker and easier as adapters welded directly to double wall fittings reduce the number of required junctions.

Leak monitoring systems and a comprehensive range of tools and equipment for correct system installation complete the SMARTFLEX/SMARTCONTAINMENT range.

We’re happy to help you

Correct installation requires appropriate tools and installer training. It is important that piping is transported and handled correctly at all times and that the handler abides by all instructions relating to cutting, cleanliness and welding. Forgeweld is happy to provide its customers with the necessary help and guidance.

Packaging: Pipes measuring 90 mm and less are usually supplied in coils or straight lengths of 5.6 m, while those measuring 110 mm and larger are always supplied in 5.8 m lengths.

Click here to download our NUPI piping brochure (PDF)