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NPT threaded API 602 / BS 5352Threaded forged steel gate valve, 1/2" to 2"
A rising‑stem gate valve for isolation, with NPT threaded ends, 1/2" to 2" (DN15 to DN50), in Forged steel ASTM A105. Rated 800 PSI, built to API 602 / BS 5352 and tested to API 598. Graphite packed — isolation duty only, never throttling.
The Threaded forged steel gate valve
Isolation duty, NPT threaded ends, built to API 602 / BS 5352.
A rising‑stem gate valve for isolation, with NPT threaded ends, in 1/2" to 2" (DN15 to DN50). The body is Forged steel ASTM A105, rated 800 PSI, designed and manufactured to API 602 / BS 5352 with ends to ASME B1.20.1 NPT and inspection and testing to API 598.
Fully open, the gate lifts clear of the bore and the valve presents almost no restriction and almost no pressure drop. That is what a gate valve is for. It is not a throttling valve: held part‑open, flow across the partly‑raised gate vibrates it and erodes both gate and seat, and the damage is permanent. To regulate flow, use a globe valve.
- ⚠ Isolation only. Fully open or fully shut — never throttle a gate valve. A throttled gate eventually will not shut off at all.
- The highest‑duty valve in this range. 800 PSI and 425 °C, tested to 21.0 MPa — seven times the flanged shell test, from a body a fraction of the size. Forging is what buys it.
- ⚠ NPT only. No BSPP option on this variant. If your pipework is BSPP, use the SS316 800 PSI valve, which offers both.
- ⚠ A105 is plain carbon steel with no corrosion resistance. For corrosive duty at the same pressure use the SS316 800 PSI version.
- Threaded is effectively permanent. Removing a screwed valve means breaking the pipework. Where the joint must never leak but the valve may need replacing, consider the socket weld version instead.
- Tested to 21.0 MPa shell and 15.4 MPa seal, with gas tightness at 0.6 MPa. Proof tests, not working pressures. The figures.
Three angles on the same valve. All photographs of the stocked item, not renders.
Specification
Everything that goes on a purchase order.
| Size range | 1/2" to 2" (DN15 to DN50) |
| End type | NPT threaded — to ASME B1.20.1 NPT |
| Body material | Forged steel ASTM A105 |
| Working pressure | 800 PSI |
| Maximum working temperature | −29 °C to 425 °C |
| Design and manufacture | API 602 / BS 5352 |
| Inspection and test | API 598 |
| Shell or body test | 21.0 MPa |
| Seal test | 15.4 MPa |
| Gas tightness test | 0.6 MPa |
| Stem | Rising stem, handwheel operated, multi‑turn |
| Packing | Graphite |
| Duty | Isolation only — never for throttling. For throttling use globe valves |
| Stock | Held in Malaysia or Singapore |
Bill of materials
All 17 parts, with the manufacturer’s own item numbers.
| No | Part name | Material |
|---|---|---|
| 1 | Body | ASTM A105 |
| 2 | Seat | ASTM A276 410 + STL |
| 3 | Wedge | ASTM A276 420 |
| 4 | Stem | ASTM F182 F6A |
| 5 | Gasket | SS304 + Graphite |
| 6 | Bonnet | ASTM A105 |
| 7 | Bonnet Nut | ASTM A194 2H |
| 8 | Bonnet Bolt | ASTM A193 B7 |
| 9 | Packing | Graphite |
| 10 | Pin | ASTM A307-A |
| 11 | Gland | ASTM A276 410 |
| 12 | Gland Flange | ASTM A105 |
| 13 | Gland Bolt | ASTM A193 B7 |
| 14 | Gland Nut | ASTM A194 2H |
| 15 | Yoke Sleeve | ASTM A276 410 |
| 16 | Lock Nut | Carbon Steel |
| 17 | Handwheel | ASTM A197 |
- The item numbers are the manufacturer’s, taken from the sectional drawing rather than renumbered 1 to 17. We publish them as printed so a spares order matches the drawing.
- Graphite packing is what allows the temperature rating. A gate valve seats metal to metal and packs the stem with graphite — no PTFE in the pressure boundary, which is why this range goes far past a ball valve.
Sizes and dimensions
6 sizes. Dimensions in millimetres.
Letters follow the manufacturer’s drawing. L is the face‑to‑face length and the figure that decides whether the valve drops into your run; H is the height with the stem risen. Where a letter is ambiguous we have left it exactly as published rather than guess at it.
| Size | Bore d | Face‑to‑face L | Height H | Handwheel W |
|---|---|---|---|---|
| 1/2" | 10.3 | 79 | 145 | 100 |
| 3/4" | 13.5 | 92 | 145 | 100 |
| 1" | 18 | 111 | 170 | 125 |
| 1 1/4" | 23 | 120 | 190 | 160 |
| 1 1/2" | 29 | 120 | 215 | 160 |
| 2" | 36 | 140 | 240 | 180 |
- ⚠ Allow headroom above the height figure. This is a rising stem valve — the stem and handwheel travel up as it opens, and you need clearance above that plus room to turn the wheel.
- Measure the gap in the run against L, and on a replacement measure the valve coming out rather than trusting a drawing.
Test pressures
Factory proof tests. Not working pressures.
| Nominal Pressure | 800 PSI |
| Shell Test Pressure | 21.0 MPa |
| Seal Test | 15.4 MPa |
| Gas-Tightness Test | 0.6 MPa |
| Max Working Pressure | -29&°;C to 425 &°;C |
- ⚠ Do not design to these. They are proof tests well above the working rating — the body or shell test proves the casting or forging, the seal test proves the gate against its seat.
- Inspected and tested to API 598, the standard common to all ten gate valve variants, which is what makes these figures comparable across the range. All ten.
Not sure this is the right one?
End type first, then material, then pressure.
Choose this one when
- Your pipework is NPT threaded — checked, not assumed.
- The duty suits Forged steel ASTM A105.
- 800 PSI covers the working pressure.
- Your specification names API 602 / BS 5352.
- You need to isolate, not regulate.
Choose something else when
- You need to throttle → globe valves. A gate valve will be damaged doing it.
- You need fast, frequent isolation → ball valves, a quarter turn instead of many.
- Your pipework is a different end type or flange standard → pick by end type.
- You need more pressure at small bore → the threaded or socket weld forged valves at 800 PSI.
- You need corrosion resistance → an SS316 variant.
- You need larger than 6" → butterfly valves.
All ten, side by side: the comparison table. Other variants: ANSI 150 cast iron · ANSI 150 cast steel · ANSI 150 forged steel · ANSI 150 SS316 · JIS 10K cast iron · JIS 10K SS316 · Threaded SS316 200 PSI · Threaded SS316 800 PSI · Weld end forged steel.
Questions we get asked
The ones that come up on the phone.
What is the Threaded forged steel gate valve?
A rising‑stem gate valve for isolation duty with NPT threaded ends, 1/2" to 2" (DN15 to DN50), in Forged steel ASTM A105, rated 800 PSI. Designed and manufactured to API 602 / BS 5352, ends to ASME B1.20.1 NPT, inspected and tested to API 598. Tested at 21.0 MPa shell and 15.4 MPa seal.
Can I use it to control flow?
No. It is an isolation valve — fully open or fully shut. Held part‑open, flow across the partly‑raised gate makes it vibrate and erodes both the gate and its seat, and that damage is permanent: a throttled gate valve eventually will not shut off at all. To regulate flow use a globe valve.
What temperature will it take?
−29 °C to 425 °C. Gate valves reach this because they seat metal to metal and pack the stem with graphite — there is no PTFE in the pressure boundary. A PTFE‑seated ball valve stops at 150 °C. All ten compared.
Will it fit my pipework?
It is NPT threaded, to ASME B1.20.1 NPT. BSPP and NPT are not interchangeable — a mismatched pair engages, feels tight, then leaks later. If you are unsure which is on the existing pipework, send a photo before ordering.
What is it made of?
Forged steel ASTM A105. The full numbered parts list is on this page, with the manufacturer’s own item numbers preserved so a spares order matches the drawing. ⚠ This is plain carbon steel with no corrosion resistance. If stainless was specified because of the fluid or the environment, it is not a substitute.
Why is it rated 800 PSI?
Because the body is forged and small. A forged body is denser and stronger than a casting, and a small body contains pressure far more easily than a large one — so this valve is tested to 21.0 MPa, around seven times the flanged shell test in the same range. The trade is size: it stops at 2".
Do I need extra height above the valve?
Yes. This is a rising stem valve — the stem and handwheel travel up as it opens. Allow clearance above the published height plus room to turn the wheel. It is the dimension most often forgotten when replacing a valve in a tight space.
Gate valve or ball valve?
Temperature and speed decide it. Gate valves in this range work to 425 °C because they seal metal‑to‑metal with graphite packing; the PTFE‑seated ball valves stop at 150 °C. But a ball valve is a quarter turn and a gate valve is many turns. For hot service, gate. For fast or frequent isolation, ball.
What sizes do you hold in stock?
1/2" to 2" (DN15 to DN50), held in Malaysia or Singapore. Send the size and the end type and we will confirm availability and a landed price — transport, currency, duties and taxes already inside the figure.
Catalogue
Direct PDF download — no form, no email address.
Send the end type, the size and the temperature
We will confirm the NPT threaded actually matches your pipework, check the temperature against this variant, tell you if a globe valve is the right tool instead, and quote a landed price. Stock in Malaysia and Singapore.