Elevator Guide Rails: A Comprehensive Guide
At the core of a reliable elevator system is the elevator guide rail. Choosing the right one is crucial for safety, efficiency, and longevity in your elevator operations. This article outlines key considerations when selecting elevator guide rails.
Types of Elevator Guide Rails
Understanding the types of elevator guide rails is crucial for ensuring the stable operation of elevators.
There are primarily two main types: T-type guide rails and hollow guide rails.
T-Type Guide Rails:
The most common type, named for its cross-sectional shape resembling the letter “T.”
This type is widely used.
Choosing the correct guide rail is determined by use and operating conditions of the elevator.
Stainless steel rails may be used in a building by the sea, while steel rails may be sufficient indoors.
Elevator guide rails are produced in different types and sizes.
The EN 81-20 and EN 81-50 standards valid in the European Union are among the basic standards.
These standards determine the strength, durability, and fire safety of the rails.
T-Type Guide Rails: Characteristics and Applications
T-type guide rails are the most common type, characterized by their T-shaped cross-section. These rails ensure the elevator moves accurately along its track, preventing deviation.
They are manufactured according to ISO 7465, specifying dimensions, tolerances, material properties, and surface quality.
These rails can be cold drawn (indicated by /A) or machined (/B or /BE), with machining offering higher precision.
The choice of manufacturing process impacts surface roughness, with machined rails offering smoother surfaces.
T-type guide rails provide stable support and guidance, ensuring elevator stability during operation.
Their applications span various elevator types, from passenger to service elevators.
Properly installed T-type guide rails minimize noise, vibration, and maintenance costs, promoting a smoother ride.
Hollow Guide Rails
Hollow guide rails are another type used in elevator systems.
While information on their specific characteristics is less readily available, their design likely aims to reduce weight while maintaining structural integrity.
The hollow construction may contribute to vibration dampening, enhancing ride comfort.
Material selection would consider factors like strength, durability, and resistance to corrosion.
Applications might include elevators where weight is a critical factor or where specific vibration control is needed.
Like T-type rails, hollow guide rails must adhere to relevant standards such as EN 81-20 and EN 81-50 in the European Union.
Proper installation is crucial to ensure safety and smooth operation.
Regular inspections and maintenance are essential to detect any signs of wear or damage.
The cost of hollow guide rails depends on factors such as material, dimensions, and manufacturer.
Manufacturing Standards and Specifications
Elevator guide rails are manufactured to strict standards, ensuring durability and accuracy. Key standards include ISO 7465 and EN 81-20/50. These specifications cover dimensions, tolerances, material properties, and testing methods for reliable performance.
ISO 7465 Standard
ISO 7465 is a widely used international standard for elevator guide rails. It specifically applies to T-type guide rails, addressing crucial aspects like dimensions and acceptable deviations. The standard also defines the essential material properties required for safety. It defines surface quality standards and rigorous test methods to ensure reliability.
This standard ensures the safety and reliability of elevators. ISO 7465 sets requirements for passenger and service elevators. It covers guide rails used for both lift cars and counterweights. Guide rails compliant with ISO 7465 are designated using a specific format. The standard specifies issues such as surface quality.
Examples include ISO 7465-T70/A, ISO 7465-T89/B, and ISO 7565-T90/BE. Following ISO 7465 ensures that guide rails meet international benchmarks. This contributes to the smooth, safe, and efficient operation of elevators worldwide.
EN 81-20 and EN 81-50 Standards (European Union)
EN 81-20 and EN 81-50 standards are fundamental in the European Union. They set out the essential requirements for elevator guide rails. These standards define the strength and durability, ensuring the rails withstand operational stresses. They cover fire safety features. These features are crucial for protecting passengers in emergency situations.
Compliance with EN 81-20 and EN 81-50 is mandatory for elevators operating within the EU. These standards guarantee a high level of safety and reliability. They address design, construction, and testing. Elevators must meet these requirements to be certified for use.
The standards also influence the cost. The material quality impacts cost. The rail type, dimensions, and manufacturer affect the price. Manufacturers must adhere to these standards. This ensures that elevator guide rails meet stringent safety and performance criteria.
Material Properties and Quality Control
Elevator guide rails have strict standards to guarantee their durability and accuracy. The quality of these rails needs to be spot-on. Therefore, there are strict standards to guarantee their durability.
Steel Grade and Composition (E275 B)
According to ISO 7465 standard, the tensile strength of the steel has to be between 370 N/mm and 520 N/mm. Therefore, E 275 B coded steel is used for machined guide rail production. The tensile strength of guide rail ensures the safety grip having sufficient support during the brake mechanism taking place.
E 275 B Steel composition includes: (C): 0,14-0,20; (Si): 0,19; (Mn): 0,58-0,69; (P): 0,010-0,012; (S): 0,010-0,021. Carbon content is the most important content in steel. Increased carbon content in steel increases the breaking point and tensile strength.
Silicon acts as a reducing and deoxidizing agent. Manganese improves toughness and strength properties of steel. Phosphorus and Sulphur are toxic agents in the steel, reducing elongation and toughness. The hardness of guide rail ensures the safety grip to gain sufficient friction.
Surface Roughness and Straightness Tolerances
Surface roughness measures the surface structure, calculated as a vertical deviation from its ideal shape. High deviations mean a rough surface, while low values indicate smoothness. Roughness measuring instruments state roughness in Ra values. A key difference between cold drawn and machined rails is blade roughness.
Smooth, flawless blades ensure comfort and velocity, impacting the safety grip’s break distance. Cold drawn rails have a surface roughness of 1,6 µm ─ 6,3 µm (longitudinal and transverse). Machined guide rails should be Ra ≤ 1,6 µm (longitudinal) and 0,8 µm ౼ 3,2 µm (transverse).
Straightness is a tolerance controlling the line’s form on the blade surface. Bending can cause erratic cabin rides. ISO standard specifies 0.05 mm parallelism between the bottom foot surface and the top blade surface, enhancing smoothness and comfort.
Installation and Maintenance
Understanding the handling and storage procedures is crucial. Proper installation is vital for stable elevator operation. Regular maintenance ensures longevity and safety of the elevator system.
Handling and Storage Procedures
Packages must be stored horizontally on wooden blocking, placed for each level and at the same distance from the ends. Appropriate storage prevents any permanent deformation and linearity loss. Packages should be protected from direct sunlight and precipitation, kept closed under a roof. The storage temperature should be between 5 ─ 40 degrees.
Rails must be carried carefully to prevent plunging and crushing. Protective caps must be removed just before installation. Special packing solutions fulfill customer logistic needs and guide rail protection, including sea packing. Protective caps guarantee quality preservation even at the installation site. Packages are neatly closed airtight with desiccant silica gels to prevent corrosion.
Packages must be lifted with forklifts or a crane with two slings, one sling at each end. The minimum distance between the slings must be 220 cm, lifting points 140 cm from each end. Handle one package at a time.
Importance of Proper Installation
An elevator should not be expected to operate regularly and safely on guide rails that do not possess the minimum quality standards and that are not installed properly. Proper installation ensures stability, preventing deviations and slipping during operation. High-quality guide rails, when correctly installed, provide stable support and guidance, enhancing the elevator’s overall safety and performance.
Accurate alignment with the funnel is maintained, preventing swaying and tilting. Smooth rail surfaces and flawless joints ensure no burring and rail jumps, impacting comfort, noise, vibration, and maintenance costs. Proper installation also guarantees the safety grip has sufficient support during emergency braking.
The precision of the guide height is vital for a perfect joint and providing a linear surface, ultimately ensuring passengers a smooth and secure ride. Therefore, adherence to installation standards is critical.