What Is a Stainless Steel Flange?

Flange is also called flange or flange. The flange is a part that connects the pipe to the pipe, and is connected to the pipe end. There are holes in the flange, and the bolts tightly connect the two flanges. The flanges are sealed with gaskets. Flange is divided into threaded (wire) flange and welding flange.

Stainless steel flange

Flange is also called flange or flange. The flange is a part that connects the pipe to the pipe, and is connected to the pipe end. There are holes in the flange, and the bolts tightly connect the two flanges. The flanges are sealed with gaskets. Flange sub-thread connection (wire connection) flange and welding

1. Connect the pipeline and maintain the sealing performance of the pipeline;

2. Facilitate the replacement of a certain section of pipeline;

3. It is easy to disassemble and check the pipeline condition;

4, to facilitate the closure of a certain section of pipeline.

Specification: 1/2 80 (DN10-DN5000)

Pressure level: 0.25Mpa to 250Mpa (150Lb to 2500Lb)

Common standards:

National standard: GB9112-88 (GB9113 · 1-88 GB9123 · 36-88)

American Standard: ANSI B16.5, ANSI 16.47 Class 150, 300, 600, 900, 1500 (TH, LJ, SW)

Japanese standard: JIS 5K, 10K, 16K, 20K (PL, SO, BL)

German standard: DIN2527, 2543, 2545, 2566, 2572, 2573, 2576, 2631, 2632, 2633, 2634, 2638

(PL, SO, WN, BL, TH)

Italian standards: UNI2276, 2277, 2278, 6083, 6084, 6088, 6089, 2299, 2280, 2281, 2282, 2283

(PL, SO, WN, BL, TH)

British Standard: BS4504, 4506

Standards of the Ministry of Chemical Industry: HG5010-52 HG5028-58, HGJ44-91 HGJ65-91

HG20592-97 (HG20593-97 HG20614-97)

HG20615-97 (HG20616-97 HG20635-97)

Machinery department standards: JB81-59 JB86-59, JB / T79-94 JB / T86-94

Pressure vessel standards: JB1157-82 JB1160-82, NB / T47020-2012 NB / T47027-2012

Plate type flat welding flange

Flat neck welding flange

With neck butt welding flange

Socket welding flange

Threaded flange

Flange cover

Loose sleeve flange with neck butt welding ring

Flat welding ring loose flange

Ring groove face flange and flange cover

Large diameter flat flange

Large diameter high neck flange

character

PN is

1. In order to prevent inter-eye corrosion caused by the heating of the flange cover, the welding current should not be too large, about 20% less than carbon steel electrodes, the arc should not be too long, and the interlayer should be cooled quickly.

2. The electrode should be kept dry during use. The titanium-calcium type should be dried at 150 ° C for 1 hour, and the low-a hydrogen type should be dried at 200-250 ° C for 1 hour. The coating of the electrode sticks with oil and other dirt, so as not to increase the carbon content of the weld and affect the quality of the weldment.

3. When welding stainless steel flange pipe fittings, carbides are precipitated by repeated heating, which reduces corrosion resistance and mechanical properties.

4. The chrome stainless steel flange pipe fittings have large hardened American standard flanges after welding and are prone to cracks. If the same type of chromium stainless steel electrode (G202, G207) is used for welding, it must be preheated above 300 ° C and slowly cooled around 700 ° C after welding. If the weldment cannot be subjected to post-weld heat treatment, stainless steel flange pipe fitting electrodes (A107, A207) should be used.

5, stainless steel flange, in order to improve the corrosion resistance and weldability, appropriately increase the appropriate stability elements Ti, Nb, Mo, etc., the weldability is better than chrome stainless steel flanges. When using the same type of chrome stainless steel flange electrode (G302, G307), it should be preheated above 200 and tempered at about 800 after welding. If the weldment cannot be heat treated, stainless steel flange pipe welding electrodes (A107, A207) should be used.

6, stainless steel flange pipe fittings, butt welding flange electrode has good corrosion resistance and oxidation resistance, widely used in chemical, fertilizer, petroleum, medical machinery manufacturing.

Flange (flange is also called flange or flange. It is a part that connects the pipe to the pipe. It is connected to the end of the pipe. There are holes in the flange that can be bolted to make the two flanges tight. The gasket is used between the flange Sealed. Flanged pipe fittings refer to pipe fittings with flanges (flange or joints). It can be cast, can also be formed by screwing or welding. Flange (joint) by a pair of methods Blue, a gasket and several bolts and nuts. The gasket is placed between the sealing surfaces of the two flanges. After the nut is tightened, the specific pressure on the gasket surface will deform when it reaches a certain value and fill the unevenness on the sealing surface. To make the connection tight and tight. Some pipe fittings and equipment already have flanges, which is also a flange connection. Flange connection is an important connection method for pipeline construction.

The flange connection is easy to use and can withstand large pressures. The flange connection is widely used in industrial pipelines. In the home, the pipe diameter is small and the pressure is low, so the flange connection is not visible. If in a boiler room or production site, flanged pipes and equipment are everywhere.

Generally speaking, the function of the flange is to fix and seal the joint of the pipe.

Stainless steel is usually divided into 304, 304L, 316, 321, 316L and other categories.

National standard flange in English ( National standard flange ) refers to the flange plate produced in accordance with the national standard of the People's Republic of China "GB / T 9112 ~ 9124-2010 steel pipe flange".

The national standard flange standard was jointly issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China and the China National Standardization Administration on 2011-01-10, and it is a recommended standard implemented from 2011-10-01.

GB / T 9112 ~ 9124-2010 includes the following 13 standards:

Replaces the national standard GB / T9112-2000; GB / T10745-1989 standard

GB / T 9112-2010 steel pipe flange types and parameters

GB / T 9113-2010 integral steel pipe flange

GB / T 9114-2010 steel pipe flanges with neck thread

GB / T 9115-2010 butt-welded steel pipe flange

GB / T 9116-2010 flat welded steel pipe flange with neck

GB / T 9117-2010 Socket-welded steel pipe flange with neck

GB / T 9118-2010 butt welding ring with neck loose tube steel pipe flange

GB / T 9119-2010 flat welded steel pipe flange

GB / T 9120-2010 Butt welding ring plate loose tube steel flange

GB / T 9121-2010 flat welding ring plate loose sleeve steel pipe flange

GB / T 9122-2010 Flange ring plate loose tube steel pipe flange

GB / T 9123-2010 steel pipe flange cover

GB / T 9124-2010 steel pipe flange

Technical conditions

The pressure mark specified in this standard is divided into PN mark and Class mark.

PN marking with 12 pressure levels

They are: PN2.5; PN6; PN10; PN16; PN25; PN40; PN63; PN100; PN160; PN250; PN320; PN400

Class marked with 6 pressure levels

They are: Class 150; Class 300; Class 600; Class 900; Class 1500; Class 2500

Another layer of national standard flanges means: flanges produced in accordance with the dimensions and tolerance ranges required by national standards, which are different from flanges that are not produced in standard sizes, also known as two-standard flanges (some people call non-standard flanges) Is incorrect), usually some unscrupulous merchants will reduce the thickness of the flange and the outer diameter of the two dimensions to achieve the purpose of saving materials, and also use waste steel or scrap steel to process the flange, usually this steel is chemical composition and mechanics Wastes with substandard performance, and even flanges produced by private steelmaking in black steel plants. The old steelmaking technology used in this private steelmaking cannot guarantee mechanical properties and welding performance, and may not be able to be welded to steel pipes during use, or The steel itself has cracks, pores, etc., and will leak after welding. So try to choose the national standard flange when purchasing the flange. If you have limited funds to choose a two-standard flange, you must carefully observe and measure the flange size to avoid being fooled.