Product Details
1/4" to 1 1/2" FPT inlet by 1/4" to 1 1/2" outlet for all kinds of applications. Has optional 1/8" NPT female side unloader port if needed. Check valves control the flow of air into the receiver tank. When the compressor reaches unload pressure the check valves closes, preventing the backflow of air from the receiver tank into the discharge supply line. To determine the correct size, measure the outside diameter of the pipe that fits into your check valve, then subtract 1/4" from this measurement to determine the correct size. (pipe sizes always measure about 1/4" over the actual size)
This is a handy chart below.
Inch Size |
Dash Size |
Nominal Thread Size |
Male Thread OD |
Female Thread ID |
| 1/8 |
-02 |
1/8-27 |
13/32" (.41) |
3/8" (.38) |
| 1/4 |
-04 |
1/4-18 |
17/32" (.54) |
1/2" (.49) |
| 3/8 |
-06 |
3/8-18 |
11/16" (.68) |
5/8" (.63) |
| 1/2 |
-08 |
1/2-14 |
27/32" (.84) |
25/32" (.77) |
| 3/4 |
-12 |
3/4-14 |
1 1/16" (1.05) |
1" (.98) |
| 1 |
-16 |
1-11.5 |
1 5/16" (1.32) |
1 1/4" (1.24) |
| 1 1/4 |
-20 |
1 1/4-11.5 |
1 21/32" (1.66) |
1 19/32" (1.58) |
| 1 1/2 |
-24 |
1 1/2-11.5 |
1 29/32" (1.90) |
1 13/16" (1.82) |
| 2 |
-32 |
2-11.5 |
2 3/8" (2.38) |
2 5/16" (2.30) |
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