Insulating Flange 30 Inch ASME B16.5 Power Plant Accessories

Product Specification

Hydrogen sulfide resistant L360NS insulating flange for gas transmission and distribution pipeline ASME B16.5

Product introduction

Insulation flange is a general term for pipe flange joints that have both the sealing performance required for buried steel pipes and the electrical insulation performance required for electrochemical corrosion protection engineering. The utility model comprises a pair of steel flanges, an insulating seal between the two flanges, a flange fastener and an insulating part of the fastener, and a pair of steel short pipes which have been respectively welded with the two flanges.

Insulation flange and insulation joint are products for petroleum, chemical industry and other industries. They are simple in structure, safe in use and reliable in performance, and have been widely praised by users. Insulation flange products have formed a series, when there are special circumstances, can be designed and manufactured according to customer requirements.

Product use

Insulation flange is mainly used between gas transmission and distribution pipeline and gas pressure regulating, metering, storage and other equipment, its main role is to isolate each section of gas transmission and distribution pipeline, equipment and pipeline mutual insulation, protect it from chemical corrosion, prolong the service life of pipeline and equipment. Products in line with SY/T0516-1997 "insulation flange design technical regulations" standard.

Product categories

This product is divided into two kinds according to the different insulation sealing parts: specific pressure sealing type insulation flange (I type insulation flange) and self-sealing type insulation flange (II type insulation flange).

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 pipe transportation medium, and it has sufficient strength and sealing performance.

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

Structure and characteristics

The structure of the old type Ⅰ insulation flange in between two slices of butt welding plane flange with flange gasket and insulation in adding insulation sleeve and insulation bolt fastening bolt of gasket. Its structure and assembly diagram are shown in Figure 1. Its flange insulation gasket materials are made of oil-resistant rubber asbestos plate, neoprene rubber plate, fabric based neoprene rubber plate and polytetrafluoroethylene. Insulation bolt sleeve and bolt insulation gasket are made of high strength phenolic laminated cloth board and pressed cloth tube. Its characteristics are: good rigidity, stable insulation performance, need to have a special installation position special installation, high cost.

The new development

The structure of the old insulation flange has been improved. In the urban gas transmission and distribution engineering, the characteristics of low pressure of urban gas transmission and distribution engineering (Pn ≤2.5MPa) and pipe network pressure Pn ≤0.4MPa are improved. Steel flat flanges are used instead of butt-welded flat flanges in pipeline network transmission and distribution projects. The insulating gaskets of the flanges are made of PTFE, oil-resistant rubber asbestos sheet, neoprene rubber and other materials. The insulating sleeve and insulating pad for fastening bolts will be two as one, and half of the insulating sleeve will be shortened to make the integral high-strength insulating sleeve pad. As shown in Fig. 2, expand the bolt hole of the steel flanges with bushing pads to be able to wear insulating bushing pads; In this way, a steel flange with special function is made. After assembly, it becomes a new type of insulation flange. Its structure and installation are shown in Fig. 3 and 4. It can be installed separately or together with the connecting valve; It not only saves the engineering cost, but also saves the site installation location. It is a new type of insulation flange which is simple and applicable, and the cost is very low.

Principle and performance

The working principle of the insulation flange is that the electrical insulation on both sides of the insulation flange is carried out by using the electrical insulation performance of the insulation gasket and the high strength insulation sleeve cushion in the insulation flange. According to the engineering practice, we have the insulation performance of the insulation flange according to the technical regulations for design of insulation flange (SY/T0516-1997) of the relevant requirements and the buried steel pipeline cathodic protection parameters test method "(SYJ23-86) of the relevant methods of testing, the test results show that the insulation gasket and the bolt insulation sleeve mat in insulation resistance value between the work surface can meet the specification requirements.

usage

The insulation flange is used in the building valve of the cathodic protection transmission and distribution network and in the buried pipe valve well which needs to be separated by potential segment (zone). The cathodic protection of each slice (section) of buried transmission and distribution network can be understood clearly by the slice (section) isolation. The cathodic protection section (area) was evaluated, and the different cathodic protection conditions were treated. When the protection potential of adjacent pieces (areas) is the same (or similar) and meets the requirements of the protection potential, the two sides of the insulation flange can be connected across strips for unified protection; When there is a big difference in the protective potential between adjacent slices (areas) and the slices (areas) that cannot reach the requirements of the protective potential, the slices (areas) that cannot reach the requirements of the protective potential can be specially treated until they meet the requirements, and then run in continuous slices.