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Compact · BSPP only · 300 PSIBrass mini ball valve, male × female, 1/4" to 3/4"
A compact brass quarter‑turn valve, male × female, for gauge, drain and small isolation points where a full‑size body will not fit. 1/4" to 3/4" at 300 PSI. BSPP only — there is no NPT option in this range.
What a mini ball valve is for
Small isolation, where a full‑size valve will not fit.
A mini ball valve does the same quarter‑turn job as the full‑size valves on this range, in a much smaller body. It is a male × female pattern, which means it screws directly into a female port and presents a female thread on the other side — so it drops straight into a gauge tapping, a drain point, a sample point or an instrument line without an adaptor.
It is the only variant on this range offered in BSPP alone. Every other one is available in NPT as well, so if your pipework is NPT this valve is not an option — use the SS316 mini, which is offered in both.
- ⚠ 300 PSI, like the full‑size brass valve. That is a third of every stainless variant on this range. If you need more from a compact body, the SS316 mini is 1000 PSI in the same sizes.
- ⚠ Not all brass. Body, cap and stem are brass and the ball is chrome‑plated brass, but the handle is aluminium, the nut is steel and the O‑ring is NBR. The steel nut is the part to watch in a damp installation.
- Male × female saves a fitting. The male end goes into the existing port and the female end takes the gauge or the tube fitting. On a crowded manifold, not needing an extra nipple is often the reason this valve gets specified.
- Reduced bore, and that is the point. These are isolation valves for instrument and drain duty, not flow devices. Bore figures are in the table.
- Leave room for the lever. It still needs a clear 90° sweep, and on a small valve in a tight cluster that is easy to overlook. Check the width and length columns before ordering.
Specification
Everything that goes on a purchase order.
| Size range | 1/4" to 3/4" (DN8 to DN20) |
| Pattern | Male × female — threads into a female port, presents a female thread |
| Body material | Brass |
| Working pressure | 300 PSI cold — derate for temperature |
| Working temperature | −29 °C to 150 °C |
| Connection type | BSPP only — there is no NPT option in this variant |
| Bore | Reduced bore — an isolation valve, not a flow device |
| Seat | PTFE |
| Operation | Quarter turn manual lever |
| Typical duty | Gauge tappings, drain and sample points, instrument isolation |
| Stock | Held in Malaysia or Singapore |
Bill of materials and sectional drawing
All 8 parts and what each is made of.
| No | Part name | Material |
|---|---|---|
| 1 | Body | Brass |
| 2 | Cap | Brass |
| 3 | Seat | PTFE |
| 4 | Ball | Chrome-plated brass |
| 5 | Stem | Brass |
| 6 | Handle | Aluminium |
| 7 | O-Ring | NBR |
| 8 | Nut | Steel |
The manufacturer’s sectional drawing. The callout numbers correspond to the part numbers in the table above.
- ⚠ Not all brass. Body, cap and stem are brass and the ball is chrome‑plated brass, but the handle is aluminium, the nut is steel and the O‑ring is NBR. The steel nut is the part to watch in a damp installation.
- The seat is PTFE, which is what sets the 150 °C ceiling and why the pressure rating falls as the line warms. The derating curve.
- 8 parts is a simple valve. The full‑size stainless two‑piece lists thirteen. Fewer parts in a smaller body — which is why it fits, and why it does less.
- The lever is aluminium. Lighter and cheaper than a stainless lever, and outside the pressure boundary — but it is the part most likely to be knocked or corroded on an exposed installation.
Sizes and dimensions
4 sizes. Dimensions in millimetres.
Check the width and length against the space you have — on a crowded gauge manifold these are the dimensions that decide whether the valve fits, and the lever still needs a clear 90° sweep.
| Size | Bore D | Height H | Length L | Width B | Weight (kg) | Part no, BSPP |
|---|---|---|---|---|---|---|
| 1/4" | 8 | 27 | 40 | 22 | 0.06 | VL-B-BMF-G-300-04-NI |
| 3/8" | 8 | 27 | 41 | 22 | 0.08 | VL-B-BMF-G-300-06-NI |
| 1/2" | 10 | 29 | 44 | 22 | 0.09 | VL-B-BMF-G-300-08-NI |
| 3/4" | 13 | 33 | 53 | 22 | 0.13 | VL-B-BMF-G-300-12-NI |
- The bore is well under the thread size. These are isolation valves — sized to shut off a small line reliably, not to pass maximum flow. If you need flow, use a full‑size full‑bore valve.
- Several sizes share a body. Where the dimensions repeat across adjacent sizes, the valves are machined from the same blank with a different thread — so the physical envelope does not change even though the connection does.
- Weight is negligible compared to the pipework, so these can generally be carried on the tubing — but a gauge hanging off one is a different matter, and that wants supporting.
Not sure this is the right one?
A mini valve is chosen on space first, then pressure.
Choose this one when
- You are isolating a gauge, drain, sample or instrument point.
- Space is the constraint and a full‑size body will not fit.
- You want to avoid an extra nipple or adaptor — male × female does it in one part.
- The duty is within 300 PSI and the thread form is BSPP only.
Choose something else when
- You need 1000 PSI or a different material in the same footprint → SS316 mini ball valve.
- Flow matters → a full‑bore two‑piece.
- You need larger than 1" → two‑piece or brass, both to 4".
- You need to divert or mix → L‑port or T‑port.
- Service must happen without a line shutdown → three‑piece.
All eight, side by side: the comparison table. Other variants: 1‑piece · 2‑piece · 3‑piece · L‑port · T‑port · Brass · SS316 mini.
Questions we get asked
The ones that come up on the phone.
What is a mini ball valve used for?
Small isolation where a full‑size valve will not fit — gauge tappings, drain and sample points, and instrument lines. It is a male × female pattern, so it threads directly into an existing female port and presents a female thread for the gauge or tube fitting, saving an adaptor on a crowded manifold.
What does male x female mean?
One end has a male thread and the other a female thread. The male end screws into the port you are isolating; the female end receives the gauge, the tube fitting or the next component. It means you can add isolation to an existing tapping without adding a nipple.
What pressure does it take?
300 PSI cold. That is the same as the full‑size brass valve and about a third of every stainless variant on this range. If you need more from a compact body, the SS316 mini gives 1000 PSI in overlapping sizes. Both figures derate as the line warms: about 67% at 150 °C. The curve.
What thread forms is it available in?
BSPP only. This is the one variant on the whole range without an NPT option — so if your pipework is NPT, use the SS316 mini instead, which is offered in both. BSPP and NPT are not interchangeable: a mismatched pair engages, feels tight, and leaks later.
What is the smallest size you can supply?
1/4" in this variant. For smaller, the SS316 mini goes down to 1/8" (DN6) — it is the only variant on the range that does.
What are the internal parts made of?
Brass body, cap and stem, with a chrome‑plated brass ball and a PTFE seat. The handle is aluminium, the nut is steel and the O‑ring is NBR — so it is not an all‑brass valve, and the steel nut is the first part to show corrosion in a damp installation. Full list on this page.
Is it full bore?
No — reduced bore, and deliberately so. A mini valve exists to shut off a small line in a small space, not to pass maximum flow. The bore figures are in the size table. If flow matters, use a full‑size full‑bore two‑piece.
Which mini should I choose, brass or stainless?
Pressure and environment decide it. The SS316 mini is 1000 PSI; this one is 300 PSI. Choose SS316 for higher pressure, corrosive or marine service, or where you need NPT; choose brass for water and air at modest pressure where cost rules. The SS316 mini · all eight compared.
Catalogue
Direct PDF download — no form, no email address.
Related: SS316 mini ball valve · all ball valves · class 150 threaded fittings · all low pressure valves.
Send the thread size and what it has to isolate
We will confirm the thread form, check the envelope against your space, and quote a landed price. Stock in Malaysia and Singapore.