Stainless Steel Spring Check Valve
One-piece spring check valve cast in CF8 or CF8M stainless. The piston is spring closed — vertical or horizontal, it seals the same. Six sizes from 1/2″ to 2″ with PT, NPT or PF threads.
The spring does the closing.
A spring loaded check valve does not wait for gravity. Forward flow pushes the piston open; the moment flow stops or reverses, the stainless spring drives it back and the line is shut. Because the spring does the closing, the valve seals in vertical runs, horizontal runs and anything in between — and it closes fast, checking reverse flow before it can build into water hammer.
The 1PC runs six sizes: 1/2″, 3/4″, 1″, 1-1/4″, 1-1/2″ and 2″. Body, piston and cap are cast CF8 or CF8M — the cast forms of 304 and 316 stainless steel — poured in our own foundry and machined in-house in Taichung, Taiwan. The spring is stainless too, SS304 or SS316. Ends are threaded PT (Rc), NPT or PF; tell us which standard your line uses when you ask for pricing.
For general water and air service the CF8 build does the job; chloride-bearing media call for the CF8M check valve, because the molybdenum in 316 is what resists chloride pitting. If you are comparing spring check valve manufacturers for an OEM run, note that casting, machining and assembly all happen on our own floor — one factory answers for the whole valve.
- Model
- 1PC
- Body
- CF8 / CF8M (cast 304 / 316) — body, piston and cap; spring SS304 / SS316
- Size range
- 1/2″–2″
- Thread
- PT (Rc) · NPT · PF
- Operation
- Self-acting — spring-closed piston
Where it gets used
Every valve leak tested.
Each unit is checked for leakage before shipment.
Can I install it on a vertical line?
The spring closes the piston without help from gravity, so the valve is not limited to horizontal runs. Put the line orientation and flow direction on the inquiry and we will confirm the fit; install to the flow arrow on the body.
How is it different from a swing check valve?
A swing check closes when gravity drops the disc, so it cares about orientation and closes more slowly. A spring check closes the piston as soon as flow reverses, does not rely on gravity, and takes up less room in the line. If your run is horizontal and you prefer no spring in the flow path, see our horizontal swing check valve instead.
Should I pick CF8 or CF8M?
CF8 is cast 304 — the standard choice for water, air and general service. CF8M is cast 316: the added molybdenum resists chloride pitting, so specify it for seawater-adjacent, brine or chemically aggressive lines.
Which thread standards do you make?
PT (Rc) taper threads, NPT to the North American standard, and PF to the JIS standard — all six sizes in each. Name the standard on your drawing or order and we cut to it.
Do you take OEM orders under our brand?
Yes — that is most of what we do. SZ Valves casts and machines in-house in Taichung, Taiwan, so private label, customer part numbers and your documentation requirements are all on the table. Send sizes and quantities for a quote.
