1. Non-noxious, corrosion proof, fight weighted, high mechanical strength, heat endurance, low crisp 1. Non-noxious, corrosion proof, fight weighted, high mechanical strength, heat endurance, low crisp temperature and long service life.2. Low in-tube liquid resistance, hard to settle filth, keep liquid away from pollutant,maintain maximum effective tube diameter.3. 100% oxygen proof, non- ...