1. Appearance Advantages: The inner and outer surfaces […]
Advantages: The inner and outer surfaces of the pipe fittings are flat and smooth without defects such as bubbles, pits, and residues.
Disadvantages: the inner and outer surfaces of the pipe fittings are uneven, not bright, have black spots, and have obvious pits on the inner and outer surfaces.
2. Cutting miscellaneous belt
When the products manufactured by qualified raw materials are under construction, the miscellaneous belt drilled by the powerful machine should be bright in color, and it should not be easy to crack when it continues to expand and contract. The whitish color of the cutting miscellaneous belt or the appearance of other colors are caused by the addition of recycled materials or uneven mixing of raw materials.
Advantages: bright, flat, continuous expansion and contraction, not easy to crack.
Disadvantages: The color is dark, and the expansion and contraction is easy to crack.
3.Electric welding welding port
Qualified electric welding joints should have smooth and symmetrical opposite sides along the entire circle of the pipe fitting, and the lower part of the opposite side cannot be lower than the surface of the pipe fitting; the amount of misalignment at any place on the outer circle adjacent to the opposite side on both sides of the welding should not exceed 10% of the wall thickness of the pipe; the opposite side should be solid and smooth, with a wide root. There is no need for residue, small round holes, distortion and damage under the reverse side.
Advantages: The reverse side is smooth and smooth. After the pressure at the interface, the opposite side can be longer.
Disadvantages: The back surface of the opposite side causes many vent holes. The reverse side is short after the pressure at the interface.
Advantages: The product just after manufacturing or after heating and melting has a slight plastic aroma, and the product after refrigeration has no peculiar smell.
Disadvantages: It smells like a choking nose.
5.Ignite the flame
Advantages: stable ignition and melting drops, light blue flame tip, no peculiar smell.
Disadvantages: unstable ignition, irregular dripping, and a small amount of black smoke and peculiar smell from the exhaust pipe.
The tensile strength refers to the ratio of the length of the test piece to the original length when it is broken. The higher the tensile strength, the better the product flexibility and the better the characteristics.
Advantages: stretched to 3.5 times without cracking.
Disadvantages: Elongation is easy to crack and poor ductility.
7.Air oxidation causes time
Air oxidation causes the time to accurately measure the time that the test piece causes the automatic catalytic reaction under the high-temperature CO2 standard. It is an index to evaluate the professional ability of materials in forming, manufacturing, storage, welding and application of heat resistance. The longer the air oxidation causes, the better the aging resistance and the better the characteristics of the product.