Insulation flange product introduction

The insulating flange is a general term for pipe flange joints that have both the sealing performance required for buried steel pipelines and the electrical insulation performance required for galvanic corrosion protection projects.

It includes a pair of steel flanges, insulating seals between the two flanges, flange fasteners and fastener insulating parts, and a pair of short steel pipes welded to the two flanges.

Insulating flanges and insulating joints are products produced for petroleum, chemical and other industries.

They are simple in structure, safe in use, reliable in performance, and have been widely praised by users.

Insulation flange products have formed a series, and in special cases, they can be designed and manufactured according to user requirements.

Fold and edit this paragraph’s product use
Insulating flanges are mainly used between gas transmission and distribution pipelines and gas pressure regulation, metering, storage and other equipment.

Corrosion prolongs the service life of pipelines and equipment.

The product conforms to the standard of SY/T0516-1997 “Technical Regulations on Insulation Flange Design”.

Fold and edit this paragraph’s product classification

According to the different insulating seals, this product is divided into two types:

pressure-sealed insulating flange (referred to as type I insulating flange) and self-tight sealing insulating flange (referred to as type II insulating flange).

Fold and edit this paragraph’s product features

1. It has the electrical insulation performance required by the electrical corrosion protection engineering of buried pipelines.

2. It can work reliably for a long time under the temperature and pressure required by the pipeline transportation medium, and has sufficient strength and sealing performance.

3. Reasonable structure, easy to assemble, disassemble and replace parts.

Fold and edit the structure and characteristics of this paragraph

The composition of the old type I insulating flange is to add flange insulating gaskets between two butt welding flat flanges and install insulating sleeves and insulating bolt gaskets on the fastening connecting bolts.

Its structural assembly diagram is shown in Figure 1, and its flange insulation gasket is made of materials such as oil-resistant rubber asbestos board, neoprene board, fabric-based neoprene board and polytetrafluoroethylene.

Insulating bolt sleeves and bolt insulating gaskets are made of high-strength phenolic laminated cloth boards and cloth press tubes.

Its characteristics are: good rigidity, stable insulation performance, a special installation location required for special installation, and the cost is high.

Fold and edit this paragraph for new development

Applicable improvements have been made to the structure of the old insulating flange.

In the urban gas transmission and distribution project, the city gas transmission and distribution project have low pressure (PN≤2.5MPa) and the characteristics of the pipe network pressure PN≤0.4MPa.

In the pipeline network transmission and distribution project, steel flat flanges are used instead of welded flat flanges.

Flange insulating gaskets are made of materials such as polytetrafluoroethylene, oil-resistant rubber asbestos sheets, and neoprene rubber, and the insulation of fastening bolts is replaced.

The sleeve and the insulating pad will be combined into one, and half of the insulating sleeve will be shortened to make an integral high-strength insulating pad.

As shown in Figure 1, the bolt holes of the steel flanges that pass through the gaskets are enlarged to be able to pass through the insulating gaskets;

so as to ensure that the inner diameter of the gaskets is suitable for the bolts used in the original steel flanges, thus making a special steel method.

After assembly, it becomes a new type of insulating flange.

It can be installed alone or together with the connecting valve; it not only saves the engineering cost but also saves the site installation location.

It is a simple and applicable new type of insulating flange with a particularly low cost.

The principle and performance of folding edit this paragraph

The working principle of the insulating flange is to use the electrical insulation performance of the insulating gasket in the insulating flange and the high-strength insulating gasket to perform electrical insulation on both sides of the insulating flange.

According to the actual engineering, the insulation performance of the insulating flange is in accordance with the relevant requirements in the “Technical Regulations for the Design of Insulating Flanges” (SY/T0516–1997) and the “Testing Methods for Cathodic Protection Parameters of Buried Steel Pipelines” (SYJ23- 86).

The test results show that: the resistance value of the insulating gasket and the insulating sleeve gasket of the fastening bolt between the insulating working surfaces can meet the specification requirements.

Fold and edit the usage of this paragraph
This kind of insulating flange is used in the building valves of cathodically protected transmission and distribution pipelines and buried pipe valve wells that need to be isolated by potential slicing (area).

Segmentation (area) isolation of buried transmission and distribution pipeline network can clearly grasp the cathodic protection situation of each piece (area) pipeline network;

Evaluate cathodic protection slice (area) and deal with different cathodic protection conditions;

When the protection potentials of adjacent sheets (areas) are the same (or similar) and meet the protection potential requirements, the two sides of the insulating flange can be connected by spanning strips for unified protection; when the protection potentials of adjacent sheets (areas) differ greatly

And when there are slices (areas) that do not meet the protection potential requirements, the slices (areas) that do not meet they protection potential requirements can be specially treated until they meet the requirements, and then the slices will be operated continuously.