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English Views: 0 Author: Jodie Publish Time: 2026-08-11 Origin: Site
Compact tubular flow control valve · G1/4 BSP thread · 315 bar · manual adjustment
The STU-G1/4 is a compact hydraulic flow control valve. It limits flow in one direction and lets oil return freely in the opposite direction. A knurled knob on top adjusts the throttle opening. A built-in check valve handles the reverse flow.
The valve screws directly into a G1/4 BSP pipe thread. It needs no valve block and takes very little space. That makes it a simple, low-cost choice for speed control on small hydraulic cylinders and motors. For more options, see our hydraulic flow control valves.
Turn the knurled knob to change the throttle opening. The feel is clear and repeatable. Once the flow is set, the position stays stable during normal operation.
Oil flows from port C to port V through the throttle. When oil flows back from V to C, the check valve opens. Reverse flow has very low resistance, so return strokes stay fast.
The carbon steel body has G1/4 female threads on both ends. It installs inline between two tubes or hoses. The surface is zinc or nickel plated to resist corrosion in normal hydraulic service.
Parameter | STU-G1/4 |
|---|---|
Series | STU unidirectional throttle check valve |
Thread | G1/4 BSP parallel (ISO 228) |
Nominal bore | approx. 6 mm |
Max working pressure | 315 bar (31.5 MPa) |
Max flow | 12–20 L/min (depends on pressure drop and viscosity) |
Check valve opening pressure | ≤ 0.05 MPa |
Media | Mineral hydraulic oil, ISO VG32–VG68 |
Media temperature | -20°C to +80°C |
Body material | Carbon steel, zinc/nickel plated |
Seal material | NBR standard; FKM optional |
Weight | approx. 0.15–0.30 kg |
This valve suits small to medium flows where you need speed control in one direction and fast return in the other. Common uses include:
Machine tool feed units — steady feed, quick retract.
Injection molding ejectors and cores — controlled speed, less mold shock.
Small hydraulic power units — simple speed limiting for cylinders.
Agricultural and construction equipment pilot lines.
Repair and replacement — STU series sizes are widely interchangeable.
Check the flow mark on the body. For throttled flow, oil should go from C to V.
Apply thread sealant or a bonded washer. Screw the valve inline between the tubes.
Set the flow at low pressure. Turn the knob slowly until the actuator speed is correct.
Do not use the valve as a shut-off valve. Add a ball valve if you need full closure.
Keep oil clean. Filtration at 25 µm or better protects the throttle gap.
Hand Hydraulic tests each STU-G1/4 valve before shipment. The carbon steel body is machined from bar stock, not cast, so tolerances stay tight. We provide material reports and pressure test records on request. Standard G1/4 sizes ship fast, and custom thread or seal options are available for OEM orders.
STU is the series code for a unidirectional throttle check valve. G1/4 means the valve has a 1/4 inch British Standard Pipe Parallel thread. The valve throttles flow in one direction and allows free return flow in the opposite direction.
No. The STU-G1/4 is a flow control valve, not a shut-off valve. Even when the knob is fully closed, a small amount of fluid may pass. Use a ball valve or stop valve if you need zero leakage.
The valve body shows a flow direction mark from port C to port V. Flow from C to V is throttled by the adjustable knob. Flow from V to C opens the built-in check valve and returns freely with very low resistance.
The valve works with mineral-based hydraulic oil, typically ISO VG32 to VG68. Standard NBR seals suit oil temperatures from -20 to 80 degrees Celsius. FKM seals are available for higher temperatures.
Send your system pressure, flow, media, and thread size to Hand Hydraulic through the contact page. The team will confirm the correct STU series size, seal material, and price, then prepare stock or custom parts for shipment.
Hydraulic check valves — one-way flow without throttle control.
Hydraulic needle valves — fine metering in both directions.
Hydraulic flow control valves — full STU, STB, and Z2FS series.
Hydraulic valve selection guide — how to choose the right size.
Tell us your pressure, flow, media, and thread size. We will confirm the right STU valve and send pricing.
Email: info@handhydraulic.com
WhatsApp: +86 18258773126