Conrader Piloted Unloader Check Valve — OEM Replacement Combo (Pilot + Unloader + Check)
| Specifications (As Configured) | |
|---|---|
 Vendor |
Conrader
|
 SKU |
NG20-M-SU4-14-SST
|
The Conrader piloted unloader check valve is an all-in-one combination valve that lets an air compressor run in continuous (constant-speed) operation. A single body integrates three functions — a pilot valve, a discharge unloader valve, and a check valve — for gas-engine and electric-motor driven compressors. Each valve below is factory-set to a specific pressure range and configured as a direct OEM replacement for a popular compressor brand.
How it works
The check valve prevents backflow as the compressor builds pressure. The pilot stays closed until downstream pressure reaches the unload setting, then opens and pressurizes the unloader valve, venting excess air to atmosphere. As air is used and pressure drops to the load setting, the pilot closes, the unloader closes, and the compressor builds pressure again — repeating the cycle.
Key specifications
- Function: Combination pilot + discharge unloader + check valve
- Operating pressure: 20–250 PSI (factory-set per model)
- Operating temperature: –15° to 400°F
- Max flow rating: NG-Series 30 SCFM · NSG-Series 20 SCFM
- Inlet connections: Compression tube, SAE 45° flare, or male/female NPT, 1/8"–3/4"
- Application: Gas-engine driven air compressors (also suits electric-motor units)
OEM replacement cross-reference
Select your compressor's original part from the options above. This valve directly replaces:
- Atlas Copco 1312100497
- Campbell Hausfeld 128400AV, 128410AV, ST128408AV, ST128413AV, ST128415AV
- Hitachi 885426 / EC2510E
- Ingersoll Rand 49816283C, 32262867, 56288756
- Makita LMV
- Mi-T-M 22-0270, 22-0346
- Quincy 112711, 1151M-150
- Rolair 131CVT, 131B
- Thomas 638835
Typical applications
Used on gas-engine and electric air compressors to load and unload the pump automatically — the standard control on contractor, truck-mount, and stationary compressors that run continuously.
Genuine Conrader piloted unloader check valves combine the pilot, unloader, and check valve in one rugged body for reliable continuous-run compressor control — a direct replacement for Atlas Copco, Campbell Hausfeld, Hitachi, Ingersoll Rand, Makita, Mi-T-M, Quincy, Rolair, and Thomas OEM valves.
NOTE: Actual product may be different from pictured!
Financing Options
Financing Options
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