3/8 in. Brass Inline Check Valve, Viton | 944402V
3/8 in. Brass Inline Check Valve, Viton | 944402V
Backordered at the manufacturer — estimated ship time 2–3 weeks. Need a firm date? Email sales@apexflowsolutions.com
Flat-rate shipping, nationwide- Orders under $100: $9.95
- $100 – $499.99: $14.95
- Orders $500+: quoted — real freight for your order, not a flat guess
Volume order or crossing a competitor part number? Request a quote — usually answered the same business day.
The 3/8 in. brass inline check valve with Viton seal (part 944402V) provides compact, spring-loaded backflow prevention where fuels, hydrocarbons, or heat would destroy a standard Buna-N seat — the Viton (FKM) seal runs to a maximum of 325°F and handles 125 psi saturated steam. Rated 400 psi WOG with a low 1/2 psi cracking pressure, polyetherimide disc, and a patented disc guide that prevents side loading. Female NPT both ends. Made in Italy.
Technical Specifications
| Manufacturer Part Number (MPN) | 944402V |
| Nominal Size | 3/8 in. |
| Valve Type | Inline check valve (spring-loaded poppet), brass, Viton seal |
| End Connections | Female NPT × Female NPT |
| Pressure Rating | 400 psi WOG |
| Steam Rating | 125 psi saturated steam |
| Maximum Temperature | 325°F (Viton seal) |
| Cracking Pressure | 1/2 psi |
| Seat / Seal | Viton (FKM fluoroelastomer) — fuels, hydrocarbons, elevated temperature |
| Disc | Polyetherimide — corrosion and abrasion resistant |
Dimensions
| Bore Diameter | 0.40" |
| Weight | 0.18 lb |
Materials of Construction
| Body & End Connection | Brass |
| Disc | Polyetherimide |
| Seat | Viton (FKM) |
| Spring | Stainless Steel |
Performance & Testing
- Viton (FKM) seal — fuels, oils, hydrocarbons, and service heat that Buna-N cannot take
- Low 1/2 psi cracking pressure — opens with minimal upstream pressure
- Spring-loaded for fast seating; perfect seating at both high and low pressure
- Patented disc guide prevents side loading — stable, chatter-resistant operation
- Compact, high-capacity design with a head-loss-minimizing flow profile
- Not lead-free — for potable water supply lines, choose a lead-free certified valve (see Lead-Free Valves in our Valves menu)
Other Sizes in This Series
Brass Inline Check Valve, Viton (FKM) seal, Female NPT (3/8"–4"; 400 WOG through 2", 175 WOG above). Jump to another size or add it straight to your cart:
| Size | Part # | Price | Cart |
| 3/8 in. (this page) | 944402V | $19.99 | — |
| 1/2 in. | 944403V | $22.99 | Add to Cart |
| 3/4 in. | 944404V | $33.99 | Add to Cart |
| 1 in. | 944405V | $37.99 | Add to Cart |
| 1-1/4 in. | 944406V | $65.99 | Add to Cart |
| 1-1/2 in. | 944407V | $93.99 | Add to Cart |
| 2 in. | 944408V | $120.99 | Add to Cart |
| 2-1/2 in. | 944409V | $247.99 | Add to Cart |
| 3 in. | 944410V | $385.99 | Add to Cart |
| 4 in. | 944411V | $552.99 | Add to Cart |
Typical Applications
Backflow prevention on fuel and oil transfer lines, hydrocarbon processing, hot-water and steam-condensate service to 125 psi steam, compressed air with oil carryover, and heated industrial loops beyond the 210°F limit of Buna-N. The 1/2 psi cracking pressure also suits low-head gravity and recirculation systems. Not for potable water supply (not lead-free).
Cross-References & Interchange
Replacing another brand's 3/8 in. brass inline check valve with FKM/Viton trim? Match nominal size, end connections, cracking pressure, and pressure rating for a direct fit — or send us your part number and we will confirm the interchange. Water, air, or general-purpose service? The 3/8 in. Buna-N version (944402) costs less and covers everything up to 210°F. Corrosive chemicals? Step up to the 3/8 in. 316 SS inline check valve (949402).
Availability
In stock — ships direct from the manufacturer, typically 1–3 business days.
Technical Resources
- Check Valve Types Explained (Swing vs. Spring vs. Wafer)
- How to Choose the Right Valve
- Valve Pressure & Temperature Ratings Chart
Expert Guides for This Product
- Check Valve Orientation & Installation — flow direction and mounting rules
- Check Valve Sizing Guide — why line size isn't valve size
- Slamming & Water Hammer — causes and fixes
- Check Valve Leaking? — diagnose and fix it
- Check Valve Chattering — the sizing problem nobody checks
- Buna vs. Viton Seats — which elastomer fits your media