SUNS FLOW SYSTEMS developed the manufacturing of restrained and special connection systems for ductile iron pipes ,fittings & Valves in Tangshan and Qingdao branches ,SUNS play important role for OEM manufacturing for other companies in China and worldwide from Germany, Japan, Australia, Brazil, Vietnam and others, SUNS manufacture many types of restrained connection and special connections for many applications, the need of developing the restrained and special system is the performance of using ductile iron pipes instead of other pipes, Ductile Iron pipes is easy installation, long life, withstand high pressure ,withstand  high forces and suitable for human consumption for potability of conveying drink water.



Because of the construction boom started in China in the end of last century, a big demand for pipes started, specially the big sizes 1000mm Diamater and more, China government started to build water and sewer pipelines in many areas in China like Shanxi, Hunan and North China province. The hard terrain let china government to push us and other Chinese manufacturers to develop and import  technology form world wide of special jointing  systems.

The most need for restrained systems are for above ground pipelines and where there is no thrust block used to stop pressure force to move pipes from it’s location.

The Geographic for the earth where high slope areas of which a moving soil is founded let suns develop many types of restrained joints and other special connections to hold the pipes and resist the forces generated, the main principal of designing restrained joints is calculating generated force, SUNS recommend customers to send the full data for pipeline conditions to calculate and provide best solution for joint.

SUNS have the ability to test the joint after manufacturing by applying the calculated force over the joint, by this way the client will get approved product to handle site location.

SUNS cooperate with many partners in worldwide and exchange technology, SUNS meet Chinese Standards, ISO Standards, AWWA Standards, EN Standards & JS standards for ductile Iron pipes & fittings for normal, restrained and special joints.

SUNS is the third manufacturer in China classified by production capacity however, SUNS policy stands to be number one in China for quality and developing special products to meet all client requirements.