HDPE pipes are known for their flexibility, toughness and chemical resistance. PE pipes have excellent ductility and toughness, can withstand large pressure changes. These performance characteristics make PE pipes the best choice for dynamic soil and earthquake prone areas that require rugged, durable and corrosion-resistant piping that is flexible enough to be installed and assembled in harsh and challenging environments.
We produce HDPE pipes and fittings in strict accordance with the domestic GB / T 13663 standard. JUNNUO HDPE pipes and fittings are fully compliant with ISO4427, EN12201, AS NZS 4129/4130 standard and CE certification.
It depends on the size and type of your project and the location of the installation. You must consider:
Peripheral area for pipe welding and installation - for smaller, more compact spaces using field welding, electric fusion welding is better.
The size of the pipe. The fused system is only suitable for systems ranging from 20mm to 710mm, while butt welding can perform systems up to 2000mm.
Training, certification and experience will also affect your decision. The preparation of the pipe for the two fusion methods is a meticulous manual process, however the welding itself is the biggest difference. Electric fusion welding can be a more automated process using a welding machine with parameters that are suitably fused. Butt welding has more manual components in the process.
A fused connecting pipe can be considered as a continuous pipe without a joint. On the other hand, gasket joints are a source of leakage and water loss in many water systems. If the gasket is not properly installed, if the gasket does not properly lubricate the gasket, if the gasket is not properly lubricated, if a negative pressure (vacuum) occurs in the pipe, if ground movement or bottom groove consolidation occurs, if a significant thermal change occurs, or if the gasket burns out due to surge pressure, a leak may occur. So weld joints are generally considered to be superior to gasket joints to prevent leakage.
SDR stands for the size ratio, which is the average outer diameter of the PE pipe divided by its minimum wall thickness. The use of SDR enables manufacturers to produce a standard set of DR pipes. SDR includes 11,13.6, 17, 21, 26 and 33.
In addition to HDPE pipe, JUNNUO also supply complete fittings, including: dn20-110mm socket welding fittings, dn63-800mm butt welding fittings, dn20-630mm fused fittings, dn20-110mm PP compression fittings.
Due to the use of 100% original raw materials, we guarantee that all pipes and fittings delivered to our customers comply with the ISO4427 standard or other relevant international standards. For all HDPE pipes, HDPE pipe fittings, we can provide 20 years of warranty for normal use.
The terms "DR(dimension ratio)" and "SDR(standard dimension ratio)" are widely used in the PVC pipe industry. Both terms refer to the same ratio, which is a parameter that is obtained by dividing the average outside diameter of the pipe by the minimum pipe wall thickness.
DR and SDR were developed out of convenience rather than out of necessity. They have been established to simplify standardization in the specification of plastic pipe on an international basis. Since these define a constant ratio between outer diameter and wall thickness, they provide a simple means of specifying product dimensions to maintain constant mechanical properties regardless of pipe size. In other words, for a given DR or SDR, pressure capacity and pipe stiffness remain constant regardless of pipe size.
Even though the terms DR and SDR are synonymous, one minor difference between them is that SDR refers only to a particular series of numbers, i.e., 51, 41, 32.5, 26, 21, etc. This series of "preferred numbers" is based on a geometric progression, and was developed by a French engineer called Charles Renard. These numbers are often called "Renard's Numbers."
The term DR became widely used in 1975, with the publication of AWWA C900, which governs production of small diameter PVC pressure pipe. AWWA allowed the desired pressure capacity to dictate wall thickness. Since the OD/t values generated did not happen to fall on any of Renard's Numbers, AWWA removed the "standard" designation from the SDR term.
It is interesting to note that the most widely used product for small diameter sanitary sewer in the U.S., ASTM D3034, SDR 35, provides an apparent contradiction in terms. While 35 is not a Renard Number, it is still referred as a standard dimension ratio. In fact, all OD/t ratios in D3034 are listed as SDRs whether they are included in Renard's "preferred numbers" or not. This was probably for convenience's sake. D3034 was written in 1972, prior to the popularization of the DR term. Accordingly, ASTM may have allowed all OD/t ratios to be called SDRs.
The bottom line is simple: the two terms are interchangeable. SDR=DR=OD/t.