Coliter ® Straight Return Valve – 1.0 MPa, 0–100°C, for Hydronic Heating Systems
NQ3001 Straight Return Valve – Brass Manual Balancing Valve for Radiator and Underfloor Heating Circuits
The Coliter® NQ3001 Straight Return Valve is a high-quality brass return valve designed for flow balancing, circuit isolation, and system maintenance in hydronic radiator and underfloor heating installations. Featuring a straight-through configuration, it ensures minimal pressure drop and straightforward integration into return lines. Constructed from forged lead-free brass, it includes a manual handwheel for precise flow adjustment and complete shut-off. Rated for a nominal pressure of 1.0 MPa and operating temperatures from 0°C to 100°C, it delivers reliable, long-term performance with excellent corrosion resistance. The valve complies with ISO 228 (BSP parallel) threading standards and is available in two standard sizes: DN15 (G1/2") with L=72 mm, H=26.5 mm, and DN20 (G3/4") with L=75 mm, H=29 mm. Compatible with standard radiator tails and manifold connections, the NQ3001 supports efficient heat distribution and simplified system commissioning—ideal for residential and commercial heating applications.
Installation diagram
Product Description
| DN | G | L | H |
| 15 | G1/2" | 72 | 26.5 |
| 20 | G3/4" | 75 | 29 |
Technical Specifications
Nominal Pressure: 1.0 MPa
Working Medium: Water
Working Temperature: 0℃ ≤ t ≤ 100℃
Pipe Threads: ISO 228
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Faq - Frequent questions
Introduction to Return Valve
Coliter®’s return valves are essential components for balancing and isolating return lines in hydronic radiator and underfloor heating systems. The series includes the NQ3001 straight return valve, NQ3002 angle return valve, and NQ3008 straight return valve with drain function—all featuring high-quality brass construction, PV10 (1.0 MPa) pressure rating, and operating temperatures up to 110°C. Designed with manual handwheels for precise flow adjustment and full shut-off, they enable system balancing, maintenance isolation, and easy air venting or drainage (on NQ3008). Compatible with standard radiator tails and manifold connections, these valves ensure efficient heat distribution, leak-free performance, and long-term reliability in residential and commercial heating installations.
