An all-brass swing check valve with NPT threaded ends — body, disc, cap, pin, washer and bolt all brass, gasketed with PTFE. 1/2″ to 4″ (DN15–DN100), nine sizes, 0.13 to 4.20 kg. One moving part and no handle — the flow operates it.
Tell us the size, the fluid and the flow direction — quotes within 2 working hours.
| Ends | Female NPT — must match your pipework |
|---|---|
| Range | 1/2″ to 4″ (DN15–DN100), nine sizes |
| Pressure | 200 PSI on 1/2″ and 2½″, 300 PSI on the other seven |
| Temperature | not published — we obtain it from the factory |
| Body and disc | Brass |
| Gasket | PTFE |
| Shell / seal test | not published — the only variant with no test table |
| Weight | 0.13 kg (1/2″) to 4.20 kg (4″) |
The nine-size dimension table with weights, the 8-item BOM and the sectional drawing are all on this page, as printed in the catalogue.
A disc on a hinge, inside a brass 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.
What separates it from the other four variants is not how it works but how it is put together. There is no bolted bonnet here: the cap threads on, and that is what keeps it light. Eight parts, all brass except the two PTFE gaskets, and no galvanic pair anywhere inside the valve — but also no corrosion resistance beyond what brass gives you.
Body, disc, cap, pin, plain washer and bolt are all brass; only the body gasket and the gasket are PTFE. Compare the brass ball valve, whose handle is aluminium and whose nut is steel — here there is no second metal at all.
Seven of the nine sizes read ‑300‑ and two read ‑200‑: the 1/2″ and the 2½″. The only rating figures on this valve are in the part number and in the metal — not in a table.
Water, oil and gas. On the 1/2″ the figure is cast into the metal, so the rating can be read off the valve itself long after the paperwork is gone. It is the one rating figure in this range that is in metal rather than on paper.
Dezincification thins brass over time in some water chemistries, and this valve has no published temperature limit to design against. On heating circuits or anything above ambient, we would use stainless.
0.13 kg at 1/2″ to 4.20 kg at 4″ — a fraction of the flanged equivalents. A 4″ brass check valve weighs less than a 1½″ flanged one.
No BSPT option on this variant. If your pipework is BSPT, the threaded SS316 valve offers both thread forms.
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.
Female NPT both ends. A 60° tapered thread that seals on the flanks, so it needs sealant or tape and a firm pull-up — and gives no adjustment once tight. Decide the orientation before you start.
“½ · 200 WOG” and a flow arrow. This is the photograph that settles the rating question: the 1/2″ valve says 200 in the metal, so its 200 PSI part number is right.
Screw-on brass cap with a PTFE gasket. The disc and pin come out through here. No bonnet bolting on this variant — the cap threads on, which is what keeps it light.
Everything that goes on a purchase order.
| Item | Detail |
|---|---|
| Size range | 1/2″ to 4″ (DN15 to DN100), nine sizes |
| End connection | Female NPT — no BSPT option |
| Working pressure | 200 PSI on 1/2″ and 2½″, 300 PSI on the other seven — as printed in the part numbers |
| Working temperature | not published |
| Body and disc | Brass |
| Gasket | PTFE |
| Shell test | not published |
| Seal test | not published |
| Weight | 0.13 kg (1/2″) to 4.20 kg (4″) — published for every size |
| Moving parts | One — the disc, on its 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 |
Nine sizes, millimetres, with not one blank row. L is the body length — the gap it needs in the run; H the overall height; d the bore it passes. The rating sits inside the part number — note the two that read 200.
| Size | Thread | Part no | Length L | Height H | Bore d | Weight (kg) |
|---|---|---|---|---|---|---|
| 1/2″ | NPT | VL-B-SC-N-200-08 | 45 | 31 | 12.8 | 0.13 |
| 3/4″ | NPT | VL-B-SC-N-300-12 | 55 | 36 | 17.0 | 0.18 |
| 1″ | NPT | VL-B-SC-N-300-16 | 61.5 | 43 | 23.0 | 0.28 |
| 1¼″ | NPT | VL-B-SC-N-300-20 | 68 | 54 | 29.5 | 0.45 |
| 1½″ | NPT | VL-B-SC-N-300-24 | 83 | 57 | 31.0 | 0.55 |
| 2″ | NPT | VL-B-SC-N-300-32 | 95.5 | 68 | 41.0 | 0.86 |
| 2½″ | NPT | VL-B-SC-N-200-40 | 120 | 78 | 57.0 | 1.80 |
| 3″ | NPT | VL-B-SC-N-300-48 | 144 | 86 | 66.0 | 2.60 |
| 4″ | NPT | VL-B-SC-N-300-64 | 164 | 105 | 91.0 | 4.20 |
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.
On a replacement, measure the valve coming out rather than trusting a drawing. L here is the threaded body length, not a flange face-to-face — the fittings screw into the threads.
The overall figure with the valve closed. The disc swings up inside the body, not outside it, so H does not change in service.
12.8 mm at 1/2″ and 91 mm at 4″. That is normal for a threaded check valve — but if your pressure-drop calculation assumes full bore, use these figures, not the nominal size.
A valve must not hang on the pipework, and must never be used to pull a misaligned joint together. At 4″ it weighs 4.20 kg — light, but not nothing.
The callout numbers correspond to the item numbers below. Eight parts, all brass except the two PTFE gaskets, and one moving part — the disc on its pin.
All eight parts, and only one of them moves.
| No | Part name | Material |
|---|---|---|
| 1 | Body | Brass |
| 2 | Disc | Brass |
| 3 | Cap | Brass |
| 4 | Body Gasket | PTFE |
| 5 | Pin | Brass |
| 6 | Plain Washer | Brass |
| 7 | Bolt | Brass |
| 8 | Gasket | PTFE |
Six metal parts, all brass. No steel bolt inside a brass body, no stainless washer on a brass pin — so no two dissimilar metals sitting next to each other in the fluid.
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.
A disc that chatters — which happens when the valve is oversized for the flow — wears the pin, and a worn pin lets the disc sit crooked on the seat.
Item 4 is the body gasket under the cap; item 8 is the gasket. Both PTFE, and both the only non-metallic parts in this valve.
They match the callouts on the drawing above, so a spares order matches the section. Everything here is published, not on request.
The only variant in this range with no test table at all.
The other four variants each publish a test table — a shell test, a seal test, an air test and, on two of them, a temperature range. This variant publishes none of it. There is no test table on the manufacturer’s sheet, not a blank one, and no working temperature anywhere. The only rating it carries is the PSI figure in the part number, and the one cast into the body.
200 PSI on the 1/2″ and 2½″ part numbers, 300 PSI on the other seven. Full dimensions and weights for all nine sizes. An eight-part bill of materials and a sectional drawing with matching callouts.
Cast into the 1/2″ body — water, oil and gas. That is the one rating figure on this valve that is in metal rather than on paper, and it confirms the part number.
The other threaded variant in this range is tested at 2.1 and 1.6 MPa for 200 PSI — but we are not going to attribute those to a different valve in a different material. Say so if you need them and we will ask the factory.
No published limit at all, and that matters more on brass than on steel — see the note about hot water under Construction.
Its part number reads ‑200‑ where the neighbouring sizes read ‑300‑. State the size on your enquiry and the rating is confirmed on the quotation.
On ambient water service this valve is entirely fit for purpose. On hot, pressurised or aggressive duty, tell us and we will get the figures first — or point you at the stainless version.
Type first, then end connection, then material.
All five side by side: the comparison table.
Dimensions, weights and part numbers are in the catalogue, as printed; the test table, working temperature, stock and price are not — send us the list and we will confirm all of them.
It depends on the size, and the answer is in the part number. Seven of the nine sizes carry the code ‑300‑ and two carry ‑200‑: the 1/2″, which has “200 WOG” cast into the body, and the 2½″. State the size on your enquiry and the rating is confirmed on the quotation.
Water, oil and gas. It is the traditional pressure rating marking for brass valves on non-steam service. What makes it useful: the figure is cast into the metal, so the valve’s rating can be read off the valve itself long after the paperwork is gone.
Almost. Of its eight parts the body, disc, cap, pin, plain washer and bolt are all brass; only the body gasket and the gasket are PTFE. No steel, no aluminium — unlike the brass ball valve, whose handle is aluminium and whose nut is steel.
1/2″ to 4″ NPT, nine sizes (DN15 to DN100), with full dimensions and weights for every size. Note the catalogue prints that range as “DN40–100” in one place, which is wrong — 1/2″ is DN15, not DN40. The inch figures are right; those DN figures are not.
0.13 kg at 1/2″ to 4.20 kg at 4″ — a fraction of the flanged equivalents. A 4″ brass check valve weighs less than a 1½″ flanged one. That, and the price, is why you would choose it for water service.
Because the catalogue does not print them. This is the only one of the five variants with no test table at all — not a blank one, simply none. The other threaded variant is tested at 2.1 and 1.6 MPa for 200 PSI, but we are not going to attribute those figures to a different valve in a different material. If you need them, say so and we will get them from the factory.
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.
Not on this variant — NPT only. If your pipework is BSPT, the threaded SS316 valve offers both thread forms, and it also goes down to 1/4″.
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.
Use the stainless one. Brass suits water and general service where the fluid is not aggressive and the temperature is near ambient. Dezincification thins brass over time in some water chemistries, and this valve has no published temperature limit to design against. For anything corrosive or hot there is the threaded SS316, or the flanged variants.
We hold it in our Singapore and Malaysia warehouses, out of the warehouse within 24 hours of PO. Quotes within 2 working hours. Send the sizes, quantities and the fluid — if you need test figures or a temperature, say so on the same enquiry and we will ask for both together.
Related: all swing check valves · spring check valves · dual plate check valves · all low pressure valves · our videos on YouTube.
