The ZL-4012 Ball Valve Set upgrades manifold isolation with an integrated temperature gauge on every valve, giving the installer immediate visual confirmation of flow and return temperatures at the manifold without separate sensor pockets or clip-on thermometers. Supplied as a matched pair in colour-coded red (flow) and blue (return), these 1" nickel-plated brass ball valves combine positive quarter-turn isolation with at-a-glance temperature monitoring — making them the preferred choice for commissioning and ongoing system diagnostics.
1"
BSP Size
Temp Gauge
Integrated
Pair
Supplied
Nickel Plated
Brass Body
Red & Blue
Colour Coded
Compatibility Note: Sized for the 1" MT flat-sealing connections on the ZL-117502–ZL-117512 stainless steel manifold range and most other standard 1" UFH manifolds. The red valve connects to the flow (supply) port; the blue valve to the return port. Fit before system fill to allow correct commissioning sequence.
Diagnostic Advantage: With temperature gauges fitted at both the supply and return, the installer can instantly read the temperature differential (ΔT) across the manifold during commissioning. A ΔT of 5–10°C across the circuit is the target for most UFH systems — confirming that loop flows are correctly balanced before handover.
Integrated Temperature Gauge
Each valve in the pair incorporates a direct-reading dial thermometer in the valve body. This gives a real-time temperature display at the manifold without additional sensor pockets, wiring, or clip-on accessories — reducing installation complexity and keeping the manifold assembly compact.
Nickel-Plated Brass Body
The nickel-plated brass construction provides corrosion resistance superior to uncoated brass in systems where condensation or damp conditions may affect external surfaces. The smooth nickel finish also resists flux residue and system inhibitor staining, keeping the manifold assembly looking professional long after installation.
Full-Bore Quarter-Turn Isolation
A full-bore ball valve mechanism delivers negligible pressure drop in the open position — the pipe bore is completely unobstructed when the valve is open. Quarter-turn operation ensures definitive open/closed positions with no risk of partial seating, giving reliable isolation for pressure testing or servicing.
O-Ring Sealed Faces
Flat-face connections are sealed with O-ring gaskets that compress evenly under tightening, providing a reliable leak-free joint without requiring excessive torque. This protects the manifold body threads and ensures a sound seal is achieved every time.
| Technical Specification — ZL-4012 |
| Part Number |
ZL-4012 |
| Description |
1" Ball Valve with Temp Gauge Set — Red & Blue (Pair) |
| Valve Size |
1" BSP |
| Valve Type |
Full-bore ball valve, quarter-turn |
| Body Material |
Nickel-plated brass |
| Connection Type |
BSP Male–Female with O-ring sealing faces |
| Handle Colours |
Red (flow/supply) & Blue (return) |
| Temperature Gauge |
Integrated dial thermometer on each valve |
| Quantity |
Pair (2 valves) |
| Application |
UFH manifold supply & return isolation with temperature monitoring |
| Compatible Manifolds |
ZL-117502 to ZL-117512 stainless steel manifold range and most 1" UFH manifolds |
Frequently Asked Questions
Why choose the ZL-4012 over the ZL-4130 plain ball valve set?
The ZL-4012 adds an integrated temperature gauge to each valve, allowing both flow and return temperatures to be read directly at the manifold — without separate sensor pockets or contact thermometers. This is particularly valuable during commissioning (to verify ΔT) and for ongoing diagnostics (to confirm the blending valve is delivering the correct supply temperature).
What temperature range do the gauges display?
The integrated dial thermometers are calibrated for typical hydronic heating temperatures, covering the range applicable to both conventional boiler circuits (up to ~80°C) and heat pump low-temperature systems (down to ~30°C). For precise calibration ranges, refer to the product datasheet available on request.
Do these valves include a drain or fill port?
No — these are isolation ball valves only. System fill, drain, and flush connections are provided by the integrated end-set on the ZL-series manifold body itself. The ball valves isolate the manifold from the primary circuit; the end-set manages the UFH loop side.
Can these be used with a heat pump primary circuit?
Yes. The nickel-plated brass is fully compatible with closed heat pump circuits using all standard inhibitors. The integrated temperature gauges are particularly useful on heat pump systems, where maintaining the correct low flow temperature (typically 35–45°C) is critical for SCOP performance — the gauges give immediate confirmation that the blending valve is set correctly.
