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All-welded vessels with flat heads and agitator


All-welded vessels with flat heads and mixing device are used in oil and gas, petrochemical, construction, food enterprises for the following processes:

  • mixing of single- and multiphase substances
  • homogenization
  • emulsionizing
  • suspending

Moreover, they are used for various chemical reactions and heat exchange. As a result of mixing, there is often a thermal energy release, which can be transferred to the heat-transfer medium in the coil located inside and delivered to the Consumer.

Vessels with stirrers design and manufacture is regulated by GOST 20680-2002 "Vessels and apparatus with mechanical mixing devices. General technical specifications". Thus, in accordance with it, the following requirements are applied to working environments:

  • the density should not be more than 2000 kg / m3
  • dynamic viscosity - not more than 200 Pa x s
  • temperature - from -40ºC to +350ºC
  • particles mass fraction - not more than 30%
  • liquid properties: neutral, aggressive, toxic, explosive and fire hazardous

Construction of one-piece (all-welded) apparatus with flat heads and stirrer

The main structural members are:

  • vertical cylindrical body
  • flat heads
  • flat all-in-one head
  • mechanical mixing device
  • fittings and hatches
  • internal coil (when requested)
  • heater, jacket (when requested)

The flat design of the heads determines the maximum pressure-up to 0.07 MPa. They can also be operated under vacuum with a residual overpressure of at least 665 Pa.

The all-in-one design allows to carry out vessel cleaning only through the hatch in the shell. (for comparison: in split vessels for these purposes, the head can be removed)

Fittings and hatch (es) are provided in the body, through which the filling of substances, their discharge, technological equipment installation, maintenance and cleaning of the inside surface. The number of nozzles, their nominal inside diameter and application are designed individually on the basis of the equipment requirements and the specifity of the technological process at the enterprise.

The mechanical mixing device is installed vertically in the housing on the pillar. To ensure the interface seal of the agitator shaft and the head, seals are provided, the type of which depends on the working environment:

  • double mechanical seals for liquids of 1, 2 and 3 hazard categories (aggressive, toxic, hazardous)
  • single mechanical, gland or hydraulic seals - for liquids of hazard category 4 (neutral)

The type of agitator is also selected according to the characteristics of the product, namely, the dynamic viscosity:

  • blade (three-bladed, six-bladed), gear, turbine, frame agitators for substances with dynamic viscosity up to 50 Pa x s
  • spiral, ribbon (with scrapers) agitators for fluids with viscosity more than 50 Pa x s

Operating conditions and requirements to the temperature may create the need for an internal coil, an electric heater or an external jacket that will maintain the required temperature. As heat-transfer medium in a coil or a jacket the heated steam, water, antifreeze, condensate and other liquids can be used.

All-welded apparatus with flat heads and agitator drawing

All-welded apparatus with flat heads and agitator drawing

Nozzles schedule

Designation Appliction
А product inlet
B reserve
G for pressure safety valve
D calm down pipe
Е reserve
J for pressure gauge
К, К1 heat-transfer medium inlet/outlet
L hatch
О product outlet
P for product overflow

Production of all-welded apparatus with flat heads and stirrer

Our experts design and manufacture devices of this configuration:

  • customized on the basis of a Questionnaire
  • on the basis of the Customer technical specifications

For your convenience, we offer a design letters to order a particular vessel.

Vessel 90-10-0.6-T-1ЕхdIIВТ4-N3
1-body type: all-welded with flat heads
0-without heat exchanger (1-smooth jacket, 2- with a half pipe jacket, 3-with a jacket with buckles, 4-with an electric heater)
10-nominal volume, m3
0,6-pressure, MPa
У-body material (U-carbon and structural steels, K-corrosion-resistant steels and alloys, double-layer steel)
Т-seal type (T-mechanical, gland, G-hydrosea)
1ЕхdIIВТ4-explosion-proof design of electric driving motor
N3-climatic category and placement category according to GOST 15150-69

When designing the following parameters are taken into account : pressure, processing medium specifications (density, hazard category, viscosity, temperature) and operating conditions.

As a result of the information provided, we select the metal structures material.

Thus, the most frequently used steel grades for manufacture are:

  • St3sp - carbon steel
  • 12X18H10T - stainless titaniferous austenitic steel

The outer and inner surfaces are covered with anti-corrosion compounds (soil, enamel), which allow to extend the service life and ensure safe operation (under keeping of service rules).

How to buy all-welded apparatus with flat heads and stirrer at SARRZ?

To order design, manufacture and delivery of all-welded vessels with flat heads and agitator, You may:

  • call at +7(8452)250-288
  • e-mail at  technical enquiry or design letters
  • download the Questionnaire, fill it in and e-mail it at
  • use the form "Request for quotation", provide with contact details to call You back


See also:

Vessels with elliptical head, split elliptical head and agitatorVessels with elliptical bottom, split elliptical head, agitator and welded jacketAll-welded vessels with elliptical heads and agitator
All-welded vessels with elliptical heads, agitator and jacketAll-welded vessels with elliptical heads, agitator and a half pipe jacketVessels with flat head, split flat head and agitator
All-welded vessels with flat heads and agitator