Over 30 year of endeavoring in Corrugated Stainless Steel Tube Technologies since 198,we have been specialized for manufacturing and developing CSST (helical & annular type) which are renowned for its worldwide patents. Now, Dong-A is manufacturing for the Fuel gas piping system, Solar heating system, Industrial application, Fire-fighting flexible joint and Water plumbing. We have mostly supplied our products to the developed industrial countries such as UK, Germany, USA, Italy, Japan, Russia etc. We are the leading manufacturer who has cutting edge technology on manufacturing for Corrugated Stainless Steel Tubes (CSST) with world biggest production capacity, in addition, all of our products/company has been approved by most of world-best quality certifications and/or approvals, moreover, we are supplying our corrugated tubes for fuel gas piping system to Home depot. We are ranked the 1st among Omegaflex, True flex, Pro Flex and Tight flexible. We believe this will be good for our reputation to proof our quality and reliability on our products.
Approved by USA ANSI LC 1-2005, UPC and Canada CSA in 2012, and got international certifications from Russia GOST, Kazakhstan CKT and Korea KS Conformity Certificate.
Our Product delivered in endless roll type (Max length: 1,000M, Standard length: 25~50M) It is jacketed with ultraviolet-resistant & non-flammable polyethylene, and is internationally certified material which can be recessed inside walls and be installed easily.
As it is supplied in a set with its own fittings, it is the best gas piping material to be used safely and semi-permanently.
Different from normal welding, our process with welding rod, the width of welding line or welded bead is less than 0.7mm in our unique welding process, so the thickness of the welded bead area is the same as that of mother material after welding work.
Normally, the mother material is becoming thinner by melt and welded without welding rods in the welding process, if the width of welding bead is more than 0.6mm, the thickness of welding bead area inevitably becomes narrower, for this reason, the cracks of the fatal defect affects when the tube is bent. But our flexible tubes solved this problem perfectly.
To prevent crack corrosion on welding line and welding heat affected area due to welding stress, we simultaneously take process of welding and partial heat treatment with welding heat and argon gas before making corrugation. This processing can keep the metal surface structure on the valley of corrugation same as before the process and makes bending line smooth without crack corrosion or destructions of metal surface structure, normal corrugation tube production in the world is roller-forming. During on producing corrugation tubes with this roller forming, the thickness of valley of the tube inevitably becomes thinner than that of the mother material, so when the tube is bent, there is the fatal defect that cracks in the valley of tube. However, our corrugation tubes, which is manufactured by the buckling forming (the forming that tubes are squeezed toward the axis of the tube horizontal direction) has the advantage that the thickness of the ridge is the same as that of valley, this has good effect to prevent the cracks when the products are bent. (Our bending number is at least 5 times more than ANSI/CSA Standard bending test.) Because hardness of welding bead, weld-heat-affected area, and shoulders of each tube end in our tubes are equally HV 165~ 170, we provide equal (standardized) heat treated products. Therefore, the flexibility is excellent and cracks are not formed. Since our own fitting and packing for tubes are metal joint sealing thread connection type, the leakage problems never happen even if it is installed by untrained installers.Please visit our webpage (www.dongaflexible.co.kr) that includes promotion videos.
If you sign the exclusive agreement or keep large transactions with us, we can offer D/A at 60days.
