Knowledge of a Lap Joint Flange

What is a Lap Joint Flange/Loose Flange?

A lap joint flange is used to cover the end of a pipe with flanging, the steel ring and other processes. The steel ring or flanging is a sealing surface, and the function of a flange is to press them tightly. It can be seen that the lap joint flange is not in contact with the medium because it is blocked by the steel ring or flanging. Because the flange is movable and not directly connected with the pipe, it is called loose flange or lap joint flange.

Under What Conditions is the Loose Flange Suitable for Use?

1. If there are strict requirements for the inside of the pipe and there is no weld seam inside the pipe, it is necessary to adopt the loose flange. For example, in a pneumatic conveying system, treatments and no weld seams are required inside the pipe, so the loose flange should be adopted.

2. In order to save costs, the loose flange can be used for stainless steel pipes. In this way, the flange can be made from carbon steel and the inner flanging can be made from stainless steel instead of all stainless steel flange, which can greatly save costs.

3. For the medium with strong corrosivity in the pipe, the loose flange with the welding neck collar and titanium flanging is used. And the fastening part is made from stainless steel flange, which can greatly reduce costs and has the same corrosion resistance as titanium flange.