ELLIPTICAL BOTTOMS
Manufacturing bottoms is one of the main activities of DCEP “Zarya” JSC.
Elliptical bottom is a convex metal product. Bottoms are used as structural elements of vessels, devices or tanks, closing the shell from one or two sides, depending on the configuration of the finished product.
Main parameters of the bottom:
- Diameter – ID, OD (inner or outer);
- Wall thickness – S;
- Elliptical part (convex) – hi or ho;
- Cylindrical height (straight) – h1.
Bottoms are used in various fields of industry, including petrochemical, oil refining, gas, power engineering, nuclear and space, as well as food-manufacturing and pharmaceutical. They are also used as plugs for gas or oil pipelines.
A non-specific usage of bottoms is popular in personal households: as barbecues or decoration.
Elliptical bottoms are wide-spread in industry primarily due to the characteristic properties of their geometry. Due to their large depth, equal to ¼ of the diameter + wall height + material thickness (Dx0.25+h1+s), the bottom (as part of a vessel or device) can withstand high pressure (up to 16MPa).
MANUFACTURE
For over than 13 years, the forging shop of the “Zarya” plant has been producing bottoms by hot stamping — hydraulic extrusion from a metal sheet.
A round blank of a given diameter is marked and cut from a metal sheet. Next, the blank is marked and sent to a gas furnace for heating. The hot blank is fed to a press and, with a stamp of a given diameter, gradually formed into an elliptical shape. There may be up to 7–8 such repetitions (passes).
As the number of passes increases, the residual stresses in the metal are reduced. Besides, unlike cold stamping, or flanging, the hot stamping method makes it possible not to perform additional heat treatment of the bottoms (requirements of GOST 34347-2017), because the required impact strength is often already achieved after stamping.
Therefore, the hot stamping method has a set of advantages:
- wide range of thicknesses;
- high production rate of blanks for bottoms of the same standard size;
- better strength properties of the finished product.
DCEP “Zarya” JSC manufactures elliptical bottoms in accordance with the established engineering orders, in strict accordance with GOST 6533-78 and the requirements of GOST 34347-2017.
Due to the available production accessories, the size range of elliptical bottoms is rather wide: diameter — from 159 to 2,200 mm, wall thickness — from 4 to 30 mm (size range, reference), and can be extended if necessary.
The long experience of the forging shop enables using various grades of metals and alloys for the production of bottoms: from low-alloy carbon and high-quality stainless steels produced in Russia and abroad, to heat-resistant, special corrosion-resistant alloys, titanium, bimetals, etc., for example:
- ВТ1-0;
- ст.3, 09Г2С, 20ЮЧ, SA 516 Gr70;
- 12Cr18Ni10Ti, 08Cr18Ni10Ti , AISI 304, AISI 304L, AISI 321;
- 10Cr17Ni13М2Ti, 08Cr17Ni13, AISI 316, AISI 316L, AISI 316Ti and others.
As a result, a vessel or a device with elliptical bottoms can be operated in different climates of our country and abroad.
Bottoms can be stamped from metal supplied by the customer and from the customer's blanks.
Another type of bottoms produced by the ZARYA plant are
SPHERICAL BOTTOMS
with a sphere radius of 500, 1,000, 1,800, 2,800 mm and wall thickness from 4 to 12 mm
Additional work types
In addition to stamping a bottom of the required shape, the forging shop is ready to perform:
- wall trimming with gas;
- machining (face trimming, chamfering, hole machining);
- bead blasting;
- sand blasting;
- additional heat treatment.
Besides, the following works are carried out by the certified laboratories (NDTL and TRLGM) of DCEP “Zarya” JSC:
- inspection of welded seams (radiation — X-ray and ultrasonic — US);
- ultrasonic thickness measurement;
- integrated tests and examination of the base metal and welded joints (seams) for finished bottoms and many others.
A quality certificate (data sheet) is provided for finished products. The plant is certified according to GOST R.
In addition to the products mentioned, the forging shop of DCEP “Zarya” JSC produces:
- lens compensators (DN – from 150 to 1,200 mm, wall thickness – from 3 to 6 mm).
- forgings weighing up to 100 kg.
Head of Sales Department of Serial Products:
Yelena Aleksandrovna Kudareva
(8313) 24-92-44, +7 930 800-33-33
kudareva@dzho-nn.ru
Sales manager of serial products:
Marina Alexandrovna Tsulimova
(8313) 24-92-44, +7 930 800-33-33
culimova@dzho-nn.ru