GB/T 21938-2021 Active
GB/T 21938-2021 Earth-moving machinery—Hydraulic excavator and backhoe loader lowering control device—Requirements and tests
Abstract
This document specifies the performance requirements and test methods for the lowering control device, which is installed on the boom, intermediate boom, and bucket arm hydraulic cylinders of hydraulic excavators and excavator-loaders, and is used to control the lowering speed of the boom when the hydraulic pipeline fails or ruptures.
This document applies to the lowering control device (installed with the standard linkage mechanism specified by the manufacturer) used in the lifting operation of the reverse digging device of hydraulic excavators and excavator-loaders. On machines that provide alternative linkage mechanisms, only the standard length specified by the manufacturer is tested.
General Product Information
| Document Type | National standards |
|---|---|
| Standard Status | Active |
| Standard Code | GB/T 21938-2021 |
| CCS | Construction engineering construction machinery |
| ICS | Earthmoving machinery |
| Implement Date | 2022-07-01 |