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SKU: APO-ECV15/850

APO ECV15/850 15mm ½" 850kPa ECV Expansion Control Valve (AVG, Tomson, Reliance H50 Compatible)

Insulation Option
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    Click here to be notified by email when APO ECV15/850 15mm ½" 850kPa ECV Expansion Control Valve (AVG, Tomson, Reliance H50 Compatible) becomes available.


    The APO ECV15/850 15mm (1/2") 850kPa ECV expansion control valve is used to regulate the water pressure inside hot water services, including heat pumps, electric, gas storage and solar water heaters across all mainstream brands in Australia such as Rheem, Vulcan, Rinnal, Dux, Aquamax, Thermann, Apricus and Solahart. 

    The APO ECV expansion control valve features the same threads, fitments and similar physical sizes with many other valve manufacturers such as Reliance H50, AVG, Tomson, Nefa and Reflex. This makes the APO ECV valve a perfect direct replacement to an existing valve in an old hot water heater. 

    The ECV expansion control valve regulates the pressure caused by water volume expansions during normal heating cycles in a hot water service. The ECV expansion control valve relieves this increase in pressure by a controlled water dripping into a drain line typically of 2 to 5 liters per day depending on the hot water usage.

    The ECV expansion control valve is color coded and used in conjunction with a matching color coded PTR pressure temperature relief valve of a higher pressure setting in a hot water system. Therefore, the ECV valve is designed to open first before the PTR valve does. Because the ECV expansion control valve is installed to the cold water supply line, this means the cold water is dripped out first, instead of hot water otherwise via the PTR valve. This cold water dripping feature ensures a better safety and promotes energy saving at the same time. The reduced duty cycle on the PTR valve can promote the PTR valve service life span too. 

    A functioning ECV expansion control valve is a requirement by law in many Australian states by plumbing authorities for safety. A typical sign for a faulty ECV valve is when there is a large amount of water leakage in a stream, rather than a controlled dripping. The worn out or leaking ECV valve must be replaced immediately. 

    An optional ECV valve insulation jacket is available which can reduce the heat loss and improve the hot water services' overall thermal efficiency. 

    Engineer's Notes

    The small black plastic part opposite the discharge port is called an auxiliary and serves as an emergency fail safe device by blowing itself out in case of a blockage in the discharge drain pipe. However, this auxiliary can become a failure point itself over time by unintended leakage or blow out due to manufacturing defects. The auxiliary is a threaded part and can be easily screwed in/out. The auxiliary can be replaced cheaply, instead of buying the whole valve.

    Although a faulty ECV valve itself is the most common cause for excessive leakages, this can also be caused by a faulty or insufficient pressure limiting valve, which regulates the inlet cold water supply pressure from the street mains into the tank. If the pressure limiting valve is faulty and allows excessive pressure into the water system, the ECV can leak when not faulty. In some extreme cases, the local mains street pressure may be so high to a point that the pressure limiting valve can become insufficient to limit the pressure to a typical 500kPa even with no faults. In these scenarios, a pressure limiting valve may need to be replaced or a pressure limiting valve must be used instead to limit the inlet water pressure sufficiently. 

    Lastly, plumbing codes require the ECV and PTR discharge pipes connected to a nearby drain or roof down pipes, so the discharging water is not directly dripping to the ground. In cases of no or difficult access to an actual drain, a fake drain may be allowed by the plumbing rules by digging a hole on the ground and make up a fake drain using a PVC pipe section. 

    Buy from the engineering company. Buy from All Plumbing Online.                                             

    Technical Details

    • Brand: APO
    • Model: ECV15/850
    • Watermark License Number: WMK26608
    • Pressure Rating: 850 kPa
    • Color Code Color: Green
    • Matching PTR Valve: 1000kPa Green PTR
    • Thread Size: 1/2" BSP (15mm) Male MI thread and female FI thread
    • Thread Size Physical Measurements: 20.995mm external male and internal female thread diameter (refer to the BSP sizing chart in the photo gallery)
    • Expansion Rating: 20 kW 
    • Replaceable Auxiliary 
    • Dry Spring Internal Mechanism with High Temperature Boots and Seals
    • Material: DR Brass Valve Body and Stainless Steel Levers
    • Intended Use: Electric tanks, solar tanks, gas storage tanks and heat pumps
    • SKU: APO-ECV15/850 and APO-ECV15/850-i

    Package Contents

    • APO ECV15/850 15mm (1/2") 850kPa ECV Expansion Control Valve
    • Package Weight: 300g (350g with the insulation jacket)


    All listed items are in stock. Dispatch next business day. Local pick up is available.


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