The first choice of copper valve, check the test report; in the case of adequate light, the triangle valve can be placed in the hands after the observation straight, the surface should be bright as a mirror, without any oxidation spots, no scorch traces; and close look No blisters, no blisters, no leakage plating, uniform color; no glitches, gritty hands; finger tap the surface, the fingerprints quickly spread, and not easy to scale. More keyword search: Triangle valve