Unidirectional Fixed Throttle Check Needle Valve
Fixed-orifice throttle check valve — it combines a preset flow restriction with an integrated check valve in a compact inline body. Where a fixed, repeatable flow rate is required without field adjustment, this valve delivers consistent restriction without risk of tampering or drift.
The orifice diameter (F hole size) is specified at time of ordering, and a range of cracking pressures is available to suit different circuit requirements.
Key Specifications
- Type: Unidirectional fixed throttle with integrated check
- Port sizes: 1/4", 3/8", 1/2", 3/4", 1", 1-1/4", 1-1/2" BSPP
- Max. pressure: 350 bar (all port sizes)
- Max. flow: 15 l/min (1/4") up to 300 l/min (1-1/2")
- Orifice (F hole) diameter: configurable from Ø0.1 mm to Ø2.0 mm at time of order
- Cracking pressure options: 0.5–0.7 bar (std), 1 bar, 3 bar, 5 bar, 8 bar
- Seal options: NBR (standard) — Viton available on request
- External finish: Zinc plated
- Fluid temperature: -20°C to +90°C
- Filtration standard: ISO 4406
| Thread (P-T) | Max. Pressure (bar) | Max. Flow (l/min) |
| 1/4 BSPP | 350 | 15 |
| 3/8 BSPP | 350 | 30 |
| 1/2 BSPP | 350 | 50 |
| 3/4 BSPP | 350 | 90 |
| 1" BSPP | 350 | 150 |
| 1" 1/4 BSPP | 350 | 200 |
| 1" 1/2 BSPP | 350 | 300 |






