The SMC 426 Series PVC Check Valve (Model 5720990) prevents backflow in water filtration systems with 1/8" female NPT connections on both inlet and outlet. NSF-certified construction combines durable PVC housing with BUNA-N seals for reliable one-way flow control in residential and light commercial applications.
SPECIFICATIONS
SMC 426 Series Check Valve Core Specs
Connection Type
1/8" FPT
Both inlet and outlet
Seal Material
BUNA-N
Nitrile rubber seals
Body Material
PVC
Corrosion resistant
Certification
NSF
Food-grade safe
Flow Direction
One-Way
Prevents backflow
Series
426
SMC model 5720990
TECHNICAL DETAILS
Complete Valve Specifications
| Manufacturer | SMC |
| Model Number | 5720990 |
| Series | 426 Series |
| Thread Size | 1/8" Female Pipe Thread (FPT) both ends |
| Housing Material | PVC (Polyvinyl Chloride) |
| Seal Material | BUNA-N (Nitrile Rubber) |
| NSF Certification | Yes, NSF-certified for potable water contact |
COMPATIBILITY & APPLICATIONS
Where This Check Valve Fits
The SMC 426 Series check valve installs inline on 1/8" threaded connections to prevent reverse flow in RO systems, booster pump lines, and water treatment equipment. The BUNA-N seals handle standard municipal water temperatures and pressures, while the PVC body resists corrosion from treated water. Thread both 1/8" FPT ports into existing plumbing using compatible male adapters or fittings. Ideal for protecting pumps, gauges, and sensitive filtration components from backpressure or siphoning.
💧 Install check valves with the arrow on the body pointing in the direction of desired flow. Thread connections hand-tight plus one turn with a wrench to avoid cracking the PVC body.
