Elevator tape BKNL-65 GOST 20-85

Elevator Belting (Bucket Elevator Belts)

Elevator belting is the primary traction component of a vertical bucket elevator (grain leg), designed for the continuous vertical transport of bulk materials. Structurally, it is a multi-ply rubber-textile canvas that performs a dual function: serving as a base for attaching the working elements (buckets) and transmitting traction force from the drive pulley. Unlike horizontal conveyor belts, elevator belting is designed to operate under conditions of high tensile loads and rigid fixation of hardware (bolted connections).

The scope of application for elevator belting covers key sectors of the agro-industrial complex and general industry. It is an integral part of the technological process at grain silos, port terminals, flour mills, feed mills, and oil extraction plants. The product is used for transporting grain crops, processing by-products (flour, meal, bran), seeds, as well as technical bulk mixtures.

The efficiency of an elevator depends directly on the physical and mechanical characteristics of the belt. A high-quality belt must have a low elongation coefficient to avoid the need for frequent maintenance (re-tensioning), high resistance to delamination, and sufficient transverse rigidity to support loaded buckets. The selection of a specific belt type is based on the elevator height, planned capacity, and the properties of the transported product.

Design Features and Fabric Types of Elevator Belting

The basis of strength for any elevator belt is its multi-ply traction carcass, consisting of several fabric plies bonded together by rubber interlayers. It is the type of fabric used and the number of plies that determine the breaking load of the product, its flexibility, and its ability to hold fasteners.

The most common solution on the Ukrainian market is elevator belting based on BKNL-65 fabric. This is a time-tested standard representing a belting canvas made of combined threads. The composition includes polyester fibers (Lavsan) for strength, and cotton, which provides the carcass with the necessary elasticity and stability. The nominal breaking load of one such ply is 55 N/mm, and the layer thickness is approximately 1.2 mm. BKNL-65 type belting is the optimal choice for most elevators of small and medium capacity. It is effectively the industry standard, around which the weight and traction characteristics of most existing equipment were designed, making its operational behavior fully predictable for personnel. An additional advantage is the structure of the fabric itself, which ensures tight fixation of bucket bolts, preventing them from loosening or tearing out even under significant vibrations.

For more severe operating conditions, where the elevator height exceeds standard values or increased moisture resistance is required, belts based on synthetic TK-200 fabric (Polyamide) are used. Unlike the combined BKNL, where the cotton component is prone to deterioration over time under moisture exposure, the fully synthetic carcass is absolutely hydrophobic—it does not absorb water and does not lose strength upon contact with damp grain. Furthermore, TK-200 fabric has almost four times the strength per single ply (200 N/mm) and is characterized by minimal elongation during operation, which significantly reduces the need for equipment downtime for belt re-tensioning.

A separate segment is occupied by polyurethane elevator belting, which is often indispensable for the food industry and seed plants. Due to the absence of rubber and the use of wear-resistant polymer, they leave no traces on the product, have exceptional resistance to oils and fats (which is critical for sunflower and soy), and serve 3-4 times longer than rubber-textile analogs, albeit at a significantly higher cost.

Understanding the diversity of tasks facing our clients, we have formulated our warehouse program to cover the needs of any facility—from agrarian enterprises and logistics terminals to production capacities of the food and processing industries. Our assortment constantly maintains a full size range of elevator belts: from narrow strips of 125 mm to powerful belts of 450–800 mm with varying numbers of fabric plies (from 2 to 8 layers). We do not limit you to standard rolls and perform cutting of the belt to any required length, ensuring rapid completion of your order exactly to your equipment's parameters.

Main Standard Sizes of Elevator Belting + Equipment Compatibility

The choice of belt width is regulated by the design parameters of the specific equipment model. The main limiting factors are the width of the drive pulley and the internal size of the elevator casing (legs)—the belt must move freely inside the casing without touching the walls, while having sufficient width margin relative to the bucket (standard technological clearance is 10–25 mm on each side). Our warehouse program is formed taking into account the standards of the most common types of elevator equipment in Ukraine:

• 125 mm – The basic size for grain cleaning machines, low-speed elevators of small capacity (5–10 t/h), and seed calibration lines. Compatible buckets: width 110 mm. Elevator models: N-5, N-10, early versions of NPZ-10.
• 150 mm – An intermediate standard for modernized N-10 type elevators where buckets of increased capacity are installed.
• 175 mm – One of the most popular sizes for farm enterprises (ZAV-20, ZAV-40 complexes). Compatible buckets: width 160 mm. Elevator models: N-20, NPZ-20, 2-20, as well as modern farm elevators with a capacity of 20–25 t/h.
• 200 mm – Used on reinforced versions of 25-ton elevators or imported grain dryers. Compatible buckets: width 180 mm.
• 300 mm – The "Gold Standard" for medium elevators and KZS complexes. Compatible buckets: width 260 mm. Elevator models: N-50, NPZ-50, BC-50, 2-50 (capacity 50–60 t/h).
• 400 mm – Applied on high-capacity lines (100 t/h) and BC series. Compatible buckets: width 360–370 mm. Elevator models: N-100, BC-100, NPZ-100.
• 450 mm – Powerful belting for industrial elevators and port transshipment. Compatible buckets: width 390–420 mm. Elevator models: UKZ-175, N-175 series, modern route elevators (175 t/h and above).
• 500 mm (and wider) – Belts of this width are used primarily on horizontal belt conveyors (galleries), railcar unloading stations, and port ship loaders.

Depending on loads and the type of transported product, you can order elevator belting in various combinations of strength and execution. Below is a list of the most in-demand modifications that are standard for elevator repair and assembly:

Basic Belts (BKNL-65 Fabric) – The optimal solution for grain elevators of small and medium height. Available both with rubber covers and in a lightweight version:

• Lightweight (no covers) – 125x3 0/0, 150x3 0/0, 150x4 0/0, 175x4 0/0, 300x5 0/0
• Standard (with covers) – 175x4 2/0, 200x4 2/0, 300x5 2/0, 450x6 3/1

Reinforced Belts (TK-200 Fabric) – Designed for high loads, shaft grain dryers, and operation in humid conditions. Characterized by increased strength with reduced thickness.

• Main configurations – 200x3 TK-200, 300x4 TK-200, 400x5 TK-200, 500x6 TK-200
• Oil-resistant (MBS/MOR) – Special versions for transporting sunflower seeds, soybeans, and rapeseed.

Elevator Belt Structure and Parameter Decoding

Any elevator belt is a composite product consisting of two main elements: the traction fabric carcass (core) and protective rubber covers. It is the number of fabric plies that determines the overall tensile strength of the belt. Here, it is important to maintain a balance between strength and flexibility; increasing the number of layers leads to increased belt stiffness. Installing a belt that is too thick and multi-layered on an elevator with a small diameter drive pulley will lead to excessive bending stress and rapid delamination. If such strength is required, it is more expedient to choose belts based on synthetic fabrics (TK), which provide similar or higher breaking loads with fewer layers while maintaining necessary elasticity.

The appearance and durability of the belt also depend on the rubber covers, the thickness of which is indicated in the marking by numbers (e.g., 3/1, 4/2, 0/0). The first digit indicates the thickness of the rubber on the working side, which contacts the buckets and the transported product, and the second indicates the side adjacent to the pulley. The presence of a thickened rubber layer protects the fabric from abrasive wear, grain impact, and atmospheric moisture, significantly extending the service life of the product.

A separate common class consists of elevator belts with 0/0 cover marking. These are lightweight products lacking additional rubber layers over the fabric carcass (the surface has a characteristic fabric texture). This design solution has its advantages: the belt is lighter and cheaper, and the absence of an elastic rubber layer allows for the most rigid seating of bolted connections without a "settling" effect. Furthermore, on modern elevators where drive pulleys are usually lagged (rubberized), the rough fabric base of the belt ensures excellent grip with the drive, making the presence of a bottom rubber cover unnecessary for creating traction. However, it is worth considering that 0/0 type belts are less protected from the external environment, so they are recommended primarily for use in enclosed spaces and for working with non-aggressive dry products.

Elevator Belting – Buy at Zavod Moroza + Services and Modernization

The manufacturing capabilities of Zavod Moroza allow us to implement both direct sales, shipment, and delivery of elevator belting, as well as provide related engineering services upon client request. Our in-house design bureau and service department ensure qualified solutions for selection, assembly, and technical modernization of elevator equipment.

1. Length Calculation and Splicing Methods When forming an order, it is critical to consider the method of splicing the belt into a loop. If an "overlap" installation (bolted connection of ends) is planned, a technological margin of 1.5–2.0 meters must be added to the geometric height of the elevator. As a more modern alternative, we offer kits of specialized mechanical fasteners. Using these elements avoids thickening at the joint, ensures smooth passage over pulleys, and reduces belt consumption (no long overlap required).

2. Perforation and Bucket Selection To ensure installation accuracy, we provide a mechanical belt perforation (punching) service. Holes are punched on a machine with strict adherence to pitch and the center line, guaranteeing ideal geometry for bucket attachment. We also recommend carrying out a comprehensive replacement of the traction assembly together with the buckets. Our specialists will help select the optimal bucket type (metal or polymer) and equip the order with the appropriate elevator bolts.

3. Equipment Modernization Replacing the belt is an opportune stage to review elevator performance. Engineers at our design bureau are ready to perform calculations for comprehensive modernization. For example, switching to a synthetic TK-200 type belt allows for a significant reduction in the traction assembly's own weight compared to BKNL. This releases drive power reserves, making it possible to install higher capacity buckets or apply a system of bottomless buckets (with a standard closing bucket), forming an almost continuous grain stream. Such a combination allows increasing the fill factor and raising elevator capacity by 20–30% without replacing the motor-reducer or intervening in the shaft construction.

We have moved away from the practice of selling "standard rolls"—shipment is carried out exactly to the dimensions of your elevator, which eliminates overpayment for unused remnants. If you have doubts regarding the choice of fabric type (BKNL or TK) or fastener compatibility, utilize the experience of our specialists. Contact us to check the availability of the required elevator belt size at the warehouse nearest to you, as well as to receive an exact cost calculation specifically for your task or simply for consultation.