Horizontal Inline Air Compressor Discharge Check Valve, 1/4 in to 2 in NPT
Horizontal inline discharge check valves for air compressors. The check valve sits between the pump and the tank and does one job: it lets air into the receiver and does not let it back out. Everything downstream of it depends on that, including whether the compressor will restart.
These are the horizontal inline pattern, for a discharge line that runs across rather than straight down into the tank.
Sizes
- S1096: 1/4 in NPT
- S1084: 3/8 in NPT
- S1055: 1/2 in NPT
- S1069: 3/4 in NPT
- S1062: 1 in NPT
- S1011: 1 1/4 in NPT
- S1098: 1 1/2 in NPT
- S1049: 2 in NPT
How you know yours has failed
The giveaway is air hissing back out of the unloader after the compressor shuts down, for far longer than the short puff you should hear. A leaking check valve lets the whole tank bleed back through the pump and out the unloader port, so the machine cycles on and off all night, the pump starts against pressure, and the motor works far harder than it should. Carbon and scale on the seat is the usual cause on a machine that has run hot, and it is a cheap part to replace for the damage it prevents.
Picking the size
Match the discharge line, not the tank port. Measure the thread on the fitting you are removing rather than reading the old valve, since the valve on the machine may already be the wrong one. Going up a size to reduce restriction sounds sensible but it is not: an oversized check valve may not seat reliably at the flow your pump actually produces.
Fitting it
Check the flow arrow on the body and fit it the right way round. Use thread sealant rather than tape, because tape debris on a check valve seat causes exactly the leak you are trying to fix. Let the pump cool before you work on the discharge line, and always blow the tank down first.
Related parts
We also stock vertical check valves in 1/2 in and 3/4 in, in tank check valves from 3/8 in to 1 1/2 in including the version that fits Kellogg pumps, cold start auxiliary unloaders, CDI pilot valves, tank manifolds and safety relief valves.
Not sure which one
Tell us the compressor make and model and the line size, and the Warthog Air Compressor Store team will confirm the right valve before you order.
Horizontal inline discharge check valves for air compressors in 1/4, 3/8, 1/2, 3/4, 1, 1 1/4, 1 1/2 and 2 in NPT.
NOTE: Actual product may be different from pictured!
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