The core functions and features of the check valve assembly of Atlas Copco's oil-free compressors
One-way flow control: Only allows compressed air to flow from the compressor outlet to the storage tank or downstream system, preventing air from flowing back to the compressor unit during shutdown and avoiding damage to the rotor, cylinder and other core components due to the backflow of lubricating oil (if any) or condensate water.
Oil-free compatibility: Using food-grade or medical-grade sealing materials (such as EPDM, PTFE), it is compatible with oil-free compression environments, avoiding contamination of compressed air due to aging of the sealing components.
Pressure adaptation: Depending on the model, the working pressure is typically 0-10bar (standard type) or 0-40bar (high-pressure type), ensuring reliable sealing within the designed pressure range.
Typical components
Check valve body (usually made of aluminum alloy or stainless steel, corrosion-resistant)
Valve core (with guiding structure, ensuring precise operation)
Spring (providing closing force, controlling opening pressure)
Sealing gasket / O-ring (special oil-free material, temperature-resistant - 20~120℃)
Installation flange or threaded interface (designated according to the model, commonly G-thread or flange connection)
Applicable models and replacement precautions
Model matching:
Small oil-free machines (such as GA 3-7 VSD+ Oil-free) usually use compact check valves with threaded connections
Large oil-free screw compressors (such as ZR 160-315) are mostly of flange-type check valve assemblies with buffer design
It is necessary to query the original equipment manufacturer's part number based on the machine model (such as ZT15, ZD75, etc.) and serial number to avoid size or pressure mismatches
Failure impact:
Failure of the check valve may cause: rapid drop in system pressure after shutdown, excessive load on the compressor during startup, risk of reverse rotation of the main unit (especially for variable frequency models), contamination of the downstream air, etc. Replacement is required in time.
For specific part information, it is recommended to provide the complete model of the compressor (such as ZR250 VSD FF) and the production year to query the precise check valve assembly number and installation manual through
