A pipe or discrimination

One, is the "touch" texture.

In general, particle coarse may mix impurities.

Two, is the "look" color.

PP - R pipe with lime green several, consumers often think that white is the best, really color not judging quality scale.

Three, is to "smell".

PP R is the main material of polypropylene, good pipe no breath, the poor can have strange taste, is likely to be the admixture of polyethylene, polypropylene and non.

Four, is the "pinch" hardness.

PP - R pipe with appropriate hardness, careless can pinch the deformation of the tube, certainly not PP R tube.
 
Five, is "hit" elastic.

Good PP R pipe, "resilience" good, easily broken natural not good PP R tube. But the hardness is not equal to good elasticity, some manufacturers by adding calcium carbonate had many impurities to improve hardness, how it is not broken, with a long time easily embrittlement.
 
Six, is to "burn" the smoke smell.

Material is mixed with the recycled plastics and other impurities in PP - R pipe smoke, pungent smell. Good material after burning does not smoke, no breath, after burning, melting liquid is still very clean.