The advantage of PVC lap joint flange

1. Cost saving. When the pipe material is special and expensive, the cost of welding flanges of the same material is high.

2. It is inconvenient for welding or processing or requires high strength. Such as PVC plastic pipes, glass steel pipes, and the like.

3. Easy to construct. For example, it is not easy to align the flange bolt holes during connection or to prevent the flange bolt holes from changing in the future when the equipment is replaced, etc.

The shortcoming of PVC lap joint flange

1. Low pressure.

2. The strength of the welding ring is low (especially when the thickness is below 3mm)

Flange classification

According to chemical industry standards: Integral flange (IF), threaded flange (Th), plate flat welding flange (PL), butt welding flange with a diameter (WN), flat welding flange with a neck (SO), Socket welding flange (SW), lap joint flange (PJ/SE), flat welding ring loose flange (PJ/RJ), lining flange cover (BL (S)), flange cover (BL).
According to petrochemical industry standards: threaded flange (PT), butt welding flange (WN), flat welding flange (SO), socket welding flange (SW), loose flange (LJ), flange cover (not shown).
According to the mechanical industry standard: integral flange, butt welding flange, plate flat welding flange, butt welding ring plate loose flange, flat welding ring plate flexible flange, flanging ring plate loose flange, Flange cover.

Flat welding steel flange: suitable for carbon steel pipe connection with nominal pressure not exceeding 2.5MPa. The sealing surface of a flat welding flange can be made into three types: smooth, concave, and convex, and tongue and groove. The largest amount of application. It is mostly used when the medium conditions are relatively mild, such as low-pressure unpurified compressed air and low-pressure circulating water. Its advantage is that the price is relatively cheap;

Butt fusion welding steel flange: It is used for butt welding of flange and pipe. It has reasonable structure, high strength, and rigidity, can withstand high temperature and high pressure, repeated bending and temperature fluctuation, and has reliable sealing performance. The butt welding flange with a nominal pressure of 0.25～2.5MPa adopts a concave-convex sealing surface;

Socket flange: commonly used in pipelines with PN≤10.0MPa and DN≤40;

lap joint flange: lap joint flange is commonly known as loose flange, divided welding ring looper flange, flanging looper flange, and butt welding looper flange. It is often used when the medium temperature and pressure are not high and the medium is more corrosive. When the medium is more corrosive, the part of the flange contacting the medium (flanging short joint) is made of high-grade corrosion-resistant materials such as stainless steel, and the outside is clamped by flange rings of low-grade materials such as carbon steel. to achieve sealing;

Integral flange: The flange is often integrated with equipment, pipes, fittings, valves, etc. This type is commonly used in equipment and valves. Sealing surface form: flat surface (FF), convex surface (RF), convex surface (M), concave surface (F), concave and convex surface (MF), tenon surface (T) groove surface (G), tenon groove surface (TG), ring Connection plane (RJ).