Flat bottom silos

       The international group of companies “PromInvestServis” offers a wide product range of metal silos (more than 500 models), which have different options arrangement.


There is no other supplier of silos that can offer the high quality, offered by our company. Some of the manufacturers may meet certain parameters, but none of them can conform to all the requirements:

Steel strength Coating Tensile strength
Side sheets: S350GD Z-600 (G-210) 420 N/mm2
Stiffener, up to 2 mm: S500GD Z-600 (G-210) 630 N/mm2
Stiffener, up to 3.5 mm: S550GD Z-600 (G-210) 630 N/mm2
Stiffener, up to 6 mm: S600GD Z-600 (G-210) 700 N/mm2
Roof: S350GD Z-600 (G-210) 420 N/mm2
Support towers and catwalks: S350GD Z-600 (G-210) 420 N/mm2
Platforms: S350GD Z-600 (G-210) 420 N/mm2
Handling equipment: S350GD Z-600 (G-210) 420 N/mm2

NOTE: the numbers of steel strength (350, 500, 550, and 600) indicates the load measured in kg/cm2 which steel can withstand without deformation:

350 = 3.500 kg/cm2; 500 = 5.000 kg/cm2, etc. 

Other manufacturers offer:

Steel strength Coating Tensile strength
Side sheets: S280GD Z-450 (G-140) or lower
Stiffener, up to 6 mm: S350GD Z-450 (G-140) or lower
Roof: S220GD Z-450 (G-140) or lower
Support towers and catwalks: S220GD Z-450 (G-140) or lower
Platforms: S220GD Z-450 (G-140) or lower
Handling equipment: S220GD Z-450 (G-140) or lower

Such parameters as steel strength and its coating are crucial for the project:

Steel strength: while developing the projects of elevator, such factors as wind loads, seismic activity in the area of installation, constant loading/unloading of the silo, huge temperature swings due to the climate (expansion and compression of the steel) must be taken into account. Therefore, high-strength steel is used in our silos to avoid possible structural damage that may occur due to the reasons listed above.

Coating: the outer layer of galvanization prevents corrosion, so the best (higher) level of galvanizing extends the life of steel, and accordingly, the elevator can be operated much longer.


When calculating the silos offered by our company the latest version of the standard is used:

Calculation standard: ANSI/ASAE EP433 SEP91 (R2011). Version 2011
Other suppliers offer calculation standard of 2007, 2003 and older. The improved version used by us takes into account more security parameters making the entire structure safer.


We offer smoother side wall sheets due to larger pitch of corrugation 104 mm (4”), while many other manufacturers use wall rings with smaller pitch of corrugation 67,5 mm (2,66”). Why is it more preferable for you:

The larger pitch of corrugation is, the smoother wall rings are. Such characteristics of grain as small, dirty, sticky are well known among all the people who are somehow connected with grain. Using larger pitch of corrugation means better silo cleaning, improving material unloading without any residue remaining so products are not contaminated. Accumulation of these materials can lead to mold, insects, moisture, etc. that will affect the grain in the silo. Thus, you prevent damage of the product that will be stored in the silo.

This variant of corrugation pitch is recommended for intensively used elevators. A larger pitch of corrugation makes the structure stiffer, since it reduces the friction of grain with walls inside the silo during loading and unloading.

Smoother walls are also higher and therefore fewer compounds needed which makes the structure more resistant to water. For example, the height of the sidewall sheet of our silo is 1144 mm, while other manufacturers offer sidewall sheet of 836 mm. For 4 m wall, you will only need three wall rings from us and four wall rings from other manufacturers.


Reliable and robust handling equipment is made using S350GD steel plus Z-600 galvanizing.

Chain conveyor accessories: Bucket elevator accessories:
  • Overload prevention system (overflow sensor)
  • Input hopper
  • RPM sensor
  • Output hopper
  • Wearproof bottom, lining
  • Belt misalignment detector
  • Plastic scraper flight
  • RPM sensor
  • Support feet
  • No-back detector
  • Input and output hopper
  • Maintenance platform on the head section of the bucket elevator
  • Bearing temperature detector (option)
  • Bearing temperature detector (option)
  • Lining of sidewalls (option)


    Our company together with the manufacturer Silos Cordoba (Spain) offers designing a turnkey project.

    All necessary elevator equipment can be designed and supplied by PromInvestServis (one supplier):

  • Dump pit (trains, trucks or ships)
  • Truck-train load silos
  • Truck dumpers
  • Ship load/unload systems
  • Aspiration system
  • Handling equipment: belt, chain, screw conveyors
  • Cleaning system
  • Screw extractor
  • Drying system
  • Storage facilities (warehouses)
  • Ventilation system
  • Hangars
  • Temperature monitoring
  • Walkway and support towers
  • Fumigation system
  • Cleaning towers
  • Airing system
  • Bag loading systems
  • Insulation
  • Weighing system
  • Flat bottom silos
  • Hopper system


    “PromInvestServis” offers excellent post-purchase service for our customers.

    During the warranty period, the service is more extensive and free. It includes teleassistance by phone or e-mail, problem solving, recommendations and on-site technical inspections. In case of any malfunction resulting from the fault of the manufacturer, repair or replacement of the equipment is free of charge for the customers.

    The same services are provided to the customers even after the manufacturer’s warranty has expired. The customer pays for transportation, cost of manufacturing and installation of new equipment.


    The customer’s staff is trained during the commissioning and adjustment. In this case, customer’s staff will be able to maintain the equipment adequately on their own. During the commissioning and adjustment, there is an installation supervisor of the manufacturer’s factory and technical staff of the “PromInvestServis”, which makes training possible and successful.


    Thanks to fully automated assembly lines, the manufacturing of the silos takes rather short time. Since the equipment is installed by highly skilled specialists, the high quality of the equipment is guaranteed, when ordering the installation of the silo from our company.

    It should be noted that the basic principle of our company is individual approach to each of our customers. We have been in the market at length and during this time, we have accumulated extensive experience, which makes it possible for us to fulfill the individual orders of our customers at the highest level.