An SS316 swing check valve with A351 CF8M castings and BSPT or NPT threaded ends, gasketed with PTFE. 1/4″ to 2″ (DN8–DN50) — the only swing check variant below 1/2″. Rated 200 PSI at −29 to 180 °C. One moving part and no handle.
Tell us the size, the thread form and the fluid — quotes within 2 working hours.
| Ends | Female BSPT or NPT — the two are not interchangeable |
|---|---|
| Range | 1/4″ to 2″ (DN8–DN50), 16 part numbers |
| Pressure | 200 PSI |
| Temperature | −29 °C to 180 °C |
| Body and disc | SS316 with A351 CF8M castings |
| Gasket | PTFE |
| Shell / tightness test | 2.1 MPa / 1.6 MPa |
| Weight | 0.24 kg (1/4″) to 1.78 kg (2″) |
The 16-row dimension table with weights, the 8-item BOM, the sectional drawing and the test table are all on this page, as printed in the catalogue.
A disc on a hinge, inside a stainless body, with a cap screwed on top of it.
Forward flow pushes the disc open and holds it clear of the bore; when flow stops or reverses, the disc swings shut under its own weight and the backpressure behind it. Nothing operates it — no handle, no stem, no actuator. That makes it the cheapest way to stop a stopped pump being spun backwards, and the least visible when it stops working.
Two things set this variant apart within its range. It is the only one that goes below 1/2″, and the only one offering both thread forms. The rest is as you would expect: body, disc and cap in SS316 with CF8M castings, PTFE gaskets — except for its three fasteners, which are SS304.
1/4″ and 3/8″ are available here and nowhere else in the swing check range — the flanged variants start at 1/2″ and the brass one at 1/2″ too.
VL‑S‑SC‑R‑200‑nn for BSPT and VL‑S‑SC‑N‑200‑nn for NPT, with identical dimensions and weights in both — only the thread differs. The R and N in the code are the thread form.
Items 5, 6 and 7. The pin is in the flow path, so on chloride-bearing service it will pit before the body does. The flanged SS316 variants use SS316 pins throughout — worth knowing if you chose stainless specifically for the fluid.
−29 to 180 °C, as the catalogue states — the only threaded variant in this range with a published working temperature. The brass one publishes none.
Both publish L 60, H 36.5, bore 10 mm — identical — and differ only in weight, 0.24 against 0.26 kg. The same casting, tapped to two thread sizes.
0.24 kg to 1.78 kg at 2″. BSPT and NPT weigh the same, so the weight column repeats exactly down the lower half of the table.
A flake of scale between disc and seat holds the disc fractionally open, and the valve then passes reverse flow while looking perfectly normal from outside. There is no stem position or indicator to check. A strainer is the single most effective thing you can do for a check valve.
Flow follows the arrow cast into the body; on a horizontal run the cap points up; on a vertical run flow must be upward. Never on downward flow — use a spring check for that.
All photographs of the stocked item, not renders.
“3/4 · CF8M · 200”, a flow arrow, and a heat number. The N 130722 stamped on the side is the casting’s heat number — traceable back to the melt it came from, which matters on inspected or certified work.
Screw-on stainless cap, PTFE gasket. The disc and pin come out through here — no bonnet bolting on this body, which is what lets it stay compact.
BSPT or NPT, female both ends. Two thread forms, not interchangeable — BSPT is a 55° British taper, NPT a 60° American one with a different pitch. The part number tells you which: ‑R‑ for BSPT, ‑N‑ for NPT.
Everything that goes on a purchase order.
| Item | Detail |
|---|---|
| Size range | 1/4″ to 2″ (DN8 to DN50), eight sizes per thread form |
| End connection | Female BSPT or NPT — not interchangeable |
| Working pressure | 200 PSI |
| Working temperature | −29 °C to 180 °C |
| Body and disc | SS316 with A351 CF8M castings |
| Pin, washer, bolt | SS304 — as printed |
| Gasket | PTFE |
| Shell test | 2.1 MPa |
| Tightness test | 1.6 MPa |
| Weight | 0.24 kg (1/4″) to 1.78 kg (2″) |
| Moving parts | One — the disc, on its hinge pin |
| Parts in the list | 8 |
| Operation | Automatic. No handle, stem or actuator |
| Orientation | Flow follows the cast arrow · cap up on a horizontal run · flow upward on a vertical run |
| Not an isolating valve | Fit a gate valve or ball valve as well if you need to shut the line |
| Stock | Singapore & Malaysia warehouses — out within 24 hours |
16 rows: eight BSPT sizes, then the same eight in NPT. L is the body length — the gap it needs in the run; H the overall height; d the bore it passes. The figures are identical in both thread forms — all that changes is the R or N in the part number.
| Size | Thread | Part no | Length L | Height H | Bore d | Weight (kg) |
|---|---|---|---|---|---|---|
| 1/4″ | BSPT | VL-S-SC-R-200-04 | 60 | 36.5 | 10 | 0.24 |
| 3/8″ | BSPT | VL-S-SC-R-200-06 | 60 | 36.5 | 10 | 0.26 |
| 1/2″ | BSPT | VL-S-SC-R-200-08 | 64 | 40 | 15 | 0.27 |
| 3/4″ | BSPT | VL-S-SC-R-200-12 | 79 | 49.5 | 20 | 0.45 |
| 1″ | BSPT | VL-S-SC-R-200-16 | 87 | 57 | 23 | 0.64 |
| 1¼″ | BSPT | VL-S-SC-R-200-20 | 100 | 61.5 | 30 | 0.87 |
| 1½″ | BSPT | VL-S-SC-R-200-24 | 116 | 71 | 38 | 1.32 |
| 2″ | BSPT | VL-S-SC-R-200-32 | 136 | 77 | 47 | 1.78 |
| 1/4″ | NPT | VL-S-SC-N-200-04 | 60 | 36.5 | 10 | 0.24 |
| 3/8″ | NPT | VL-S-SC-N-200-06 | 60 | 36.5 | 10 | 0.26 |
| 1/2″ | NPT | VL-S-SC-N-200-08 | 64 | 40 | 15 | 0.27 |
| 3/4″ | NPT | VL-S-SC-N-200-12 | 79 | 49.5 | 20 | 0.45 |
| 1″ | NPT | VL-S-SC-N-200-16 | 87 | 57 | 23 | 0.64 |
| 1¼″ | NPT | VL-S-SC-N-200-20 | 100 | 61.5 | 30 | 0.87 |
| 1½″ | NPT | VL-S-SC-N-200-24 | 116 | 71 | 38 | 1.32 |
| 2″ | NPT | VL-S-SC-N-200-32 | 136 | 77 | 47 | 1.78 |
The eight NPT rows carry exactly the same L, H, d and weight as the eight BSPT rows. Same body, different thread — so the size decision and the thread decision can be taken separately.
Both are L 60, H 36.5, bore 10 mm. Only the weight differs — 0.24 against 0.26 kg. That is consistent across both thread forms, so it is not a misprint.
The disc, hinge and pin lift out upward through the cap. A check valve you cannot open is a check valve nobody inspects — and this is the valve that fails without telling you.
10 mm at 1/4″ and 47 mm at 2″. If your pressure-drop calculation assumes full bore, use these figures, not the nominal size.
L here is the threaded body length, not a flange face-to-face — the fittings screw into the threads. On a replacement, measure the valve coming out rather than trusting a drawing.
The callout numbers correspond to the item numbers below. The three dimensions the size table publishes are here: L end to end, H overall height, and d the bore.
All eight parts, and only one of them moves.
| No | Part name | Material |
|---|---|---|
| 1 | Body | SS316 and CF8M |
| 2 | Disc | SS316 and CF8M |
| 3 | Cap | SS316 and CF8M |
| 4 | Body gasket | PTFE |
| 5 | Pin | SS304 |
| 6 | Plain washer | SS304 |
| 7 | Bolt | SS304 |
| 8 | Gasket | PTFE |
The pin, plain washer and bolt — items 5, 6 and 7. We publish the list as printed. Body, disc and cap are SS316 with CF8M as you would expect; the fasteners are one grade below.
The washer and bolt sit outside the bore, but the hinge pin does not. On chloride-bearing service SS304 pits before 316 does — and a worn or pitted pin lets the disc sit crooked on the seat.
The ANSI 150 SS316 and JIS 10K SS316 variants list hinge pin, bolt and nut as SS316. If you chose stainless specifically for the fluid, that is a real difference.
A351 CF8M — not a lower grade but the correct specification for cast parts, chemically equivalent to wrought 316. The marking is cast into the body, visible in the first photograph.
Everything else is a casting or a fastener. On a valve that closes every time the pump stops, those two surfaces take the whole duty cycle.
They match the callouts on the drawing above, so a spares order matches the section. Everything here is published, not on request.
Factory proof tests. Not working pressures.
| Item | Value |
|---|---|
| Normal pressure | 200 PSI |
| Shell test | 2.1 MPa |
| Tightness test | 1.6 MPa |
| Gas-tightness test | 0.6 MPa |
| Max working temperature | −29 °C to 180 °C |
The shell test is roughly twice the nominal rating and exists to prove the casting. The valve is not intended to operate there.
It is slam on flow reversal and chatter at low flow — both of which happen far below the shell rating. Chatter appears when the valve is oversized for the flow.
−29 to 180 °C. The brass one publishes neither a temperature nor a test table — so if your duty is threaded and has a temperature limit, this is effectively the choice.
A single figure, not a range — unlike the two flanged stainless variants, which print the air seal test as 0.4 to 0.7 MPa. As printed.
Three of them publish no working temperature at all, one publishes no test table at all, and the two flanged stainless variants give the air test as a range where everything else gives a single figure. All five side by side, with every one flagged, on the hub page.
Type first, then end connection, then material.
All five side by side: the comparison table.
Dimensions, weights, part numbers and the test table are in the catalogue, as printed; stock and price are not — send us the list with the thread form and we will confirm both.
1/4″ to 2″ (DN8 to DN50), eight sizes in each thread form, so 16 part numbers. This is the only swing check variant below 1/2″ — the 1/4″ and 3/8″ are available here and nowhere else in the range.
BSPT is a 55° British taper, NPT a 60° American one with a different pitch. They are not interchangeable — forced together, the joint leaks. The part number tells you which: ‑R‑ for BSPT, ‑N‑ for NPT. Dimensions and weights are identical in both forms; only the thread differs. Check your pipework, do not assume it.
Because that is how the catalogue prints it — items 5, 6 and 7 are SS304. It matters because the pin is in the flow path, so on chloride-bearing service it will pit before the body does. The flanged SS316 variants use SS316 pins throughout. If you chose stainless specifically for the fluid, say so on your enquiry.
Because they share one body. Both publish L 60, H 36.5 and a 10 mm bore — identical — and differ only in weight, 0.24 against 0.26 kg. The same casting, tapped to two thread sizes. It is consistent across both thread forms, so it is not a misprint.
200 PSI, −29 to 180 °C. It is the only threaded variant in this range with a published working temperature — the brass one publishes none. Shell test 2.1 MPa, tightness test 1.6 MPa, gas-tightness test 0.6 MPa; those are factory proof tests, not working pressures.
A351 CF8M is the cast form of 316 — the correct specification for cast parts, chemically equivalent to wrought 316. The first photograph shows “3/4 · CF8M · 200” cast into the body, plus the heat number N 130722 stamped on the side. That heat number is traceable back to the melt it came from, which matters on inspected or certified work.
Flow follows the arrow cast into the body. On a horizontal run the cap points up; on a vertical run flow must be upward. It must never be used on downward flow — a swinging disc needs gravity to close. Use a spring check for that. Leave headroom too: the disc and pin come out upward through the cap.
Because this is the valve that fails without telling you. A flake of scale between disc and seat holds the disc fractionally open, and the valve then passes reverse flow while looking perfectly normal from outside — no stem position, no indicator. A Y-strainer upstream is the single most effective thing you can do for it.
0.24 kg at 1/4″ to 1.78 kg at 2″. BSPT and NPT weigh the same. Weights are published for all sixteen part numbers — there is not a blank row in this table.
This variant stops at 2″. Above that, go flanged: ANSI 150 SS316 or JIS 10K SS316 up to 4″, or ANSI 150 cast steel up to 6″. For threaded above 2″ there is the brass one, up to 4″ NPT — but that is brass, not stainless.
We hold it in our Singapore and Malaysia warehouses, out of the warehouse within 24 hours of PO. Quotes within 2 working hours. State the thread form — BSPT or NPT — on the same enquiry, because that is what fixes the part number.
Related: all swing check valves · spring check valves · dual plate check valves · all low pressure valves · our videos on YouTube.
