FAQ

FAQ

FREQUENTLY ASKED QUESTIONS

What is the HDPE pipe?

HDPE stands for high density polyethylene (many times just referred to as PE), and is made from ethylene, which can be derived from either crude oil or natural gas.  HDPE Pipe is extremely strong, durable, flexible, corrosion free and chemical resistant.

What makes HDPE pipe unique?

HDPE pipe is joined together through a unique heat fusion process that creates a seal resulting in a strong leak-free system.

What are the advantages of HDPE pipe for municipal water and sewer use?

Other types of plastic and iron pipes require joints to turn and link the pipe. These joints tend to lose water as it flows through the pipe. HDPE pipe is fused together so that the links are equally strong or stronger than the rest of the pipe, meaning that it holds water much better than other types of pipe.

How does the leakage from HDPE pipe compare to metal and PVC pipe?

HDPE pipe is joined by a heat fusion process that forms strong and leak-free pipe. The “allowable water leakage” rate of HDPE pipe is zero. PVC and ductile iron installations have “allowable leakage rates” as high as 10 percent.

How does the overall cost of HDPE pipes compare in price with other materials?

Underground water pipes are a major long term (50-100 years) investment. In addition to comparing the initial purchase price, the long term maintenance costs and overall life-cycle costs should be carefully evaluated. According to the Federal Highway Administration, utilities spend $36 billion annually on corrosion protection of pipes. Because PE pipe does not corrode and does not leak at the joints, constant repair of aging metal pipes or leaking at the joints with all other pipes is no longer an issue. Initial cost savings are also realized with the opportunity for a trenchless installation. Compared to PVC and ductile iron, HDPE has the lowest life-cycle costs due to lower installation costs, lower repair rates, less water loss and lower energy costs.

What's the difference between PE100 raw material & PE80 raw material? Which one is better?

The designations PE80 and PE100 are based on the long-term strength of the respective materials, known as the minimum required strength (MRS). The PE80 pipes have a Minimum Required Strenght (MRS) of 8 MPa while The PE100 pipes have a MRS of 10 MPa.
PE100 raw material is a improved generation of raw material than PE80, whose performance is higher grade than PE80.

Can PE80 be welded to PE100?

Yes it can, but due to the materials being different, you will notice a difference in the bead.

What's the brand of raw material do you use?

SUNPLAST company only use high quality PE80 or PE100 raw material from world-famous suppliers. The raw materials we normally use are: YGH041 from Sinopec, P6006 from Sabic, HE3490-LS from Borealis.,etc.

What's the warranty time for SUNPLAST pipes & fittings?

Yes, Due to 100% virgin raw material used, we guarantee all of our pipes & fittings delivered to our customers can meet with ISO4427 standard or the other related international standards. For all HDPE pipes, HDPE pipe fittings, we can provide a wrranty time in quality of 15 years for normal use.

What kind of fittings can SUNPLAST provide?

Besides of HDPE pipes, SUNPLAST can also provide completed fittings, comprising: Socket fusion fittings from dn20-110mm, Butt fusion fittings from dn63-800mm, electrofusion fittings from dn20-630mm, PP compression fittings from dn20-110mm.

What does "butt fusion" mean?

Butt fusion is a thermofusion process which involves the simultaneous heating of the ends of two pipe/fitting components which are to be joined, until a molten state is attained on each contact surface. The two surfaces are then brought together under controlled pressure for a specific cooling time and a homogeneous fusion joint is formed. The resultant joint is fully resistant to end loads and has comparable performance under pressure to the pipe itself.

What does "electrofusion" mean?

Electrofusion welding is the process of joining two plastic pipes together using a single use coupler that has an integrated wire heating coil. The electrofusion control unit supplies electricity to this coil, heating it up and causing the plastic to melt. When this cools, a gas-tight joint is formed.

When the electric heating coil is energised, the plastic material touching it melts and forms an expanding pool of molten plastic which comes into contact with the surface of the pipe. The continued heating causes the pipe surface to melt and then mix with the molten plastic of the fitting. This mixing is vital to produce a good weld. Likewise, the correct delivery of energy to the heating coil is vital to create the molten plastic and allow the process to happen.

At the end of the heating cycle, the fitting and pipe are left to cool and the molten material solidifies to create a solid and sound joint. During this cooling phase, the joint must be kept completely still as movement can crack the interface and cause a leak path.

To ensure a good quality joint, the following need to be true:

  • The heating coils need to be as close to the pipe/fitting interface as possible.
  • The heat distribution is uniform over the length of the "hot zone".
  • Melt pressure and temperature are accurately controlled.
  • The heating coils are protected from damage prior to and during the welding.
What's the main difference between electrofusion & conventional heat fusion?

The main difference between conventional heat fusion and electrofusion is the method by which the heat is applied. In conventional heat fusion (butt, saddle and socket) joining, a heating tool is used to heat the pipe and fitting surfaces. The electrofusion joint is heated internally, either by a conductor at the interface of the joint or by a conductive polymer. Heat is created as an electric current is applied to the conductive material in the fitting. PE pipe to pipe connections made using the electrofusion process require the use of electrofusion couplings.

What do the terms SDR mean?

SDR stands for dimension ratio, which is the average outside diameter of a PE pipe divided by its minimum wall thickness. The use of SDR’s enables manufacturers to produce pipe to a set of standardized DR’s. SDR’s include 11, 13.6, 17, 21, 26, and 33. All SDR’s are DR’s, but the converse is not true.

Why is a fusion joint better than a gasket joint?

A fusion joined pipeline may be thought of as a continuous pipeline without joints. On the other hand, gasket joints are a source of leakage and lost water in many water systems. Leaks may occur if the gasket is improperly installed, if dirt or grit sticks to the gasket, if the gasket is not properly lubricated, if negative pressure (vacuum) occurs in the pipeline, if ground movement or subtrench consolidation occurs, if significant thermal change occurs, or if gaskets are blown out due to surge pressures. Fused joints are generally considered superior to gasket joints for leak prevention.

Should I use butt welding or electrofusion welding to join the HDPE pipes?

This depends on your project size and type, and location of installation. You have to consider:

  • The area surrounding where the pipe is to be welded and installed – electrofusion is better for smaller, tighter spaces where onsite welding is being used
  • The size of the pipe. Electrofusion systems are only available for systems ranging in size from 20mm to 710mm, whereas butt-welding can be performed up to 2000mm.
  • Training, accreditation and experience will also inform your decision. The preparation of pipes for both fusion methods is a meticulous manual process, however the weld itself is where the big difference is. Electrofusion can be a more automated process using a welding machine that has parameters set for appropriate fusion. Butt welding has more manual elements in the process.
Which standards does SUNPLAST pipes & fittings follow with?

We produce HDPE pipes & fittings strictly follow with our domestic GB/T 13663 standard. The HDPE pipes & fittings from SUNPLAST can also comply with ISO4427, EN12201,AS NZS 4129/4130 standards

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