The Non-Return Valve DN25 provides a highly efficient and protective safety solution for mid-to-high capacity hydronic heating layouts. Installers integrate this unidirectional check valve into main boiler loops, manifold pump packs, or primary distribution zones to prevent the hazardous reversal of heated water streams. Consequently, the mechanical mechanism ensures that system fluid travels strictly in one direction, safeguarding sensitive circulating pumps and secondary heat sources from damaging counter-flows or heat migration. Furthermore, the premium brass housing offers outstanding resistance to high temperatures, system pressures, and chemical additives typically present in closed heating loops. The internal spring-loaded check mechanism is precision-engineered to crack open with minimal hydraulic resistance, ensuring it does not choke pump performance during active operation.
Additionally, its standardised DN20-DN25 series profile integrates effortlessly with standard residential and light-commercial pump packs. Therefore, you can complete system piping layouts quickly while guaranteeing absolute protection against localised hydraulic backpressure.
- Unidirectional Flow Control: Restricts water movement strictly to a single direction and seals instantly if the flow attempts to reverse. Consequently, it prevents system short-circuiting and keeps active thermal zones running efficiently.
- Pump Backflow Protection: Isolates downstream pressure surges and thermal siphoning from reaching delicate pump components. Therefore, it substantially extends the operational lifespan of your primary circulating equipment.
- Robust DN25 Form Factor: Sized ideally for systems requiring flow capacities up to 70–75kW. As a result, it bridges the gap perfectly between domestic manifolds and complex commercial plant rooms.
- Low Pressure Drop Operation: The internal piston and spring assembly are optimised for low crack pressures. Additionally, this streamlined opening ensures that the valve does not cause unnecessary bottlenecks across your hydronic network.
- Heavy-Duty Brass Integrity: Manufactured from premium, corrosion-resistant alloys that endure continuous thermal expansion cycles. Subsequently, the component eliminates the risk of internal scaling or mechanical weeping over decades of service.
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DELIVERY OPTIONS:
We currently offer two shipping options to get your goods to you in a timeframe that suits:
Standard delivery to mainland UK (3-5 working days) – £9.99
Next working day delivery to mainland UK* – £11.99
*Next working day deliveries are subject to orders being placed before 1pm. The delivery window for next working day deliveries is between 8am and 5.30pm.
All orders received after 1pm on a Friday (including weekend orders), that have upgraded to next working day delivery, will be despatched on Monday for a Tuesday delivery.
Bank holidays are treated in the same way as a non-working day, so please take this additional delivery time into account when ordering.
Pallet Delivery
Next day pallet delivery to mainland UK – £72.00
Special delivery requirements
Can’t see what you’re looking for? If you require a delivery option that is not offered as standard on the website, please contact our team. Where possible we try to accommodate additional requirements, including timed delivery options and deliveries to non-mainland UK addresses.
Please note: We rely upon the services of third party couriers, and whilst we endeavour to always deliver in a timely manner there are unfortunately a few occasions when the couriers fail to deliver on the appointed day and before the specified time. Whilst this happens rarely, we cannot be held responsible for the late delivery of an item, or any costs incurred by customers’ tradespeople unable to work. Please ensure that you have your materials before booking in any trades. If your product has been delayed, we will do our best to keep you informed of any new estimated time and date of your delivery.
NEED HELP?
Our customer support team is here to help with any queries about your order and delivery requirements.
Email: customerservices@tradeunderfloor.co.uk
Call: 01283 850040
Monday to Friday | 8:30am – 4:30pm
