Production of stainless steel flanges and plugs

Production of stainless steel  flanges and plugs

Our company produces stainless steel flanges according to international standards and requirements. The flanges are made of stainless steel types AISI 316 and 321 or of any other custom type. Through our website you can purchase flat and welding neck flanges as well as pipe fittings of all types. We deliver stainless flanges throughout and beyond Ukraine at satisfactory prices.

Purchase stainless flanges – welding neck and flat.
The flange – is a flat ring or disk with symmetrical holes for fasteners such as bolts and studs that are used for tight connection of pipes and pipe valves and also for shafts and other flange elements connection. Usually flanges are produced according to the GOSTs, but it is also possible to manufacture goods in accordance with Western standards: IST (industry standards), DIN (German Institute for Standardization), ANSI (American National Standards Institute) and ASME (American Society of Mechanical Engineers). It is also possible to manufacture flanges according to customer's drafts.
The flanges vary by type:

  • welding neck;
  • flat;
  • threaded.


Welding neck stainless flange is welded to the pipe butt-to-butt, so its inner diameter shall be equal to the pipe diameter. Welding neck flanges are used in pipelines at pressures exceeding 16 MPa.

Flat stainless flange is welded to the outer surface of the pipe. Accordingly, the inner diameter of the flat flange shall be slightly larger than the outer diameter of the pipe.
Threaded flanges are very rarely used in pipe fittings.
The flanges also vary by the method of attachment:

  • for basic parts;
  • for shafts;
  • for fitting;
  • for tubes.

Major diameter flanges are manufactured by electroslag chill casting method. Then the surfaces are drilled and treated on the lathes. The flanges are not used as fastening parts, but serve as a support for fastening bolts or rivets.
To ensure high sealing, various flanges are connected in different ways: by means of tenons, slots, sockets, or knobs.
The use of stainless flanges
Modern pipelines are designed to transport various types of liquids, flammable mixtures and other types of fluid media. The most dangerous areas of the pipeline are the junctions between the tubes as well as between the equipment and the pipeline. Flanges are installed at these areas. These joining components require special attention, since their reliability ensures the smooth functioning of the entire pipeline system.
Currently, stainless steel flanges are distinguished by several key characteristics. The most important are technological and structural ones. According to the technological features round and square flanges are distinguished. Their use is due to the types of tubes and valves used. As to structural features, they depend on the standards governing the production and quality of the flanges on the territory of Ukraine.

Types of standards currently used:

  • GOST 12822-80;
  • GOST 12821-80;
  • GOST 12820-80.

Flat stainless steel flanges

Flat stainless steel welded flange is used, in accordance with GOST 12820-80, to connect pipes under pressure from 0.1 MPa to 2.5 MPa and at a temperature of the medium from -60°C to +500°C. These flanges are the most commonly used coupling elements. One of the main factors on which flat stainless steel flanges are selected is the value of nominal pressure. If the value is to 200kgs/cm2, butt welding of the flange is used. This is the most reliable method of fixation. At smaller values of the pipeline internal pressure the flat steel flange can be welded with two seams, or a mounting element on the weld ring is used.
Flat stainless steel flange used for fixing the components of the pipeline can be made of different steel grades, selected considering the following factors: the effect of operating temperature; the impact of nominal pressure; the impact of transporting medium. The selection of fasteners for all types of pipelines is done with account of all mentioned factors. The technical documentation regulating the selection of materials and types of products for operating medium traffic through the pipeline, describes in detail the items that can be used in a particular case.

Welding neck stainless steel flanges

Welding neck flanges are designed for connecting pipelines at a pressure of 0.1 MPa to 20 MPa and at a temperature from -70°C to +600°C. Flange connections are widely used in piping systems, hot and cold heat supply as well as other industries. The flanges provide a safe and tight connection of pipes to each other, joining pipes to machines and other equipment. By the type of flange connection welded neck flanges can be with and without the gap between the ends of the flanges. They are used as reinforcement flanges to connect the parts of machines, devices, various tanks and pipelines. For each type of flange connection there are two options for joining: “flange-to-flange” and “flange-to-flange with a frame”. Nowadays welding neck flanges are mostly made of steel types 321 and 316 Ti.

Currently on the market there are also welding neck flanges for pipes with pressure from 1.0 MPa to 20 MPa, with the use of different steel grades and designs. We can offer you not only standard but also custom-made flanges. In construction and assembly practice, flanges are designated by a set of numbers and letters (for example, the flange 2-100-25 st. Type 321 GOST 12821-80), where “2” – is the type of flange design; “100” means a nominal bore "DN"; “25” - nominal pressure "Pnom"; and “st. Type 321 GOST 12821-80” indicates the steel grade and the GOST according to which the flange was manufactured. The main advantage of the flange connection is its reliability, design simplicity and the components replaceability.
Moreover, welding neck flanges ensure reliability and tightness of the joint and allow connecting not only pipes and devices but also machines and large tanks. Flanges offered by our company are suitable for almost any pipe and pressure which greatly expands the range of their application.

Loose steel flanges on the welded ring
The loose flange on the welded ring in accordance with GOST 12820-80 is used to connect pipes under pressure from 0.1 MPa to 2.5 MPa and at ambient temperature from -30°C to +300°C. Flanges of this type are manufactured with a sealing surface; in some cases the manufacture of rings is accepted.
Flanges for devices and vessels
GOST 28759.4-90, GOST 28759.3-90, GOST 28759.2-90 are the standards applied to stainless (steel) butt-welded flanges for devices and vessels. Their internal diameter is 400 mm - 4000 mm, outer core size (tube bottom) - 426 mm - 720 mm. Nominal pressure is in the range of 0.6 MPa - 6.3 MPa, and the operational fluid temperature within -70°C – +54°C. The flanges are designed for use in the petroleum refining, petrochemical, chemical and other industries.
You can contact us and order the flanges of any type and size made of any steel grade, including custom-made non-standard flanges.