DFP11 Underground Fire Hydrant
Devinsan offers concealed municipal safety equipment engineered for reliable, high-volume water access and protection against external damage in public areas. Designed for long-term operational security and deep freeze resistance, these DFP11 Underground Fire Hydrant units utilize a robust, tamper-proof design to meet the critical demands of modern urban safety and aesthetic requirements.
Production Standard
Nominal Dimension (DN)
Nominal Pressure (PN)
Operating Temperature
Design
Height
Connection
Coating
Testing
DN 80 – DN 100
PN 6-PN 10-PN 16
-30° / +200°
TS EN 14384
100 cm
EN 1092-2 ISO7005-2 Flanged
Electrostatic Powder Epoxy
TS EN 14384
Application Areas
The DFP11 Underground Fire Hydrant is widely used across diverse industrial and commercial sectors, delivering reliable flow control and long‑lasting performance.
1. Water and Wastewater Systems
2. Chemical Industry
3. Food and Beverage Industry
4. Pharmaceutical Industry
5. Oil and Gas Industry
6. HVAC (Heating, Ventilation, Air Conditioning) Systems
In these applications, this type DFP11 Underground Fire Hydrant ensures precise fluid control, maintains excellent sealing integrity, and supports efficient, safe operation even under demanding conditions.
The DFP11 Underground Fire Hydrant is a crucial safety asset specifically engineered to provide immediate, high-volume water access from the buried main while being fully protected below ground level. Designed to meet the stringent demands of modern infrastructure, this specialized unit ensures reliable water delivery capability, superior physical protection, and long-term durability in high-density municipal distribution systems.
At the core of the DFP11 Underground Fire Hydrant is its reliable main valve mechanism located underground, accessed via a protected spindle mechanism and a surface box. This design allows the hydrant to supply pressurized water through an underground connection to a standpipe. A primary benefit is the inherent freeze protection; since the valve is installed below the frost line and the system drains completely, water only fills the connection riser when activated.
Manufactured from high-strength, corrosion-resistant materials (such as ductile iron) and built with a compact, flanged body, the DFP11 Underground Fire Hydrant is designed to withstand continuous system pressure and vehicle traffic loads when correctly installed beneath its surface box cover. The fully buried nature of the hydrant prevents unauthorized operation, external damage from traffic, and the need for costly break-away features.
The DFP11 Underground Fire Hydrant is ideally suited for deployment in historical districts, pedestrian zones, parks, and narrow urban streets where above-ground structures are undesirable or vulnerable to damage. Its fully concealed installation and reliable underground valve system make it a preferred choice for municipal engineers seeking a secure, high-integrity, standards-compliant solution for critical urban fire safety infrastructure.
In summary, the DFP11 Underground Fire Hydrant offers an optimal combination of safety, high-volume flow capacity, and environmental protection against freezing and traffic impact. With its dependable main valve sealing, concealed design, and critical below-ground stability, this unit stands as a trusted solution for modern emergency water supply requirements worldwide.
1. General Information
The DFP11 Underground Fire Hydrant is designed for direct flanged connection to the underground water main, requiring precise alignment and stability at depth. Proper installation is essential to guarantee safe operation, long service life, and efficient emergency water availability.
2. Safety Precautions
Installation must be performed by qualified personnel only.
Ensure strict compliance with all local safety regulations and standards concerning excavation, deep trench shoring, and connecting to pressurized municipal water lines.
Wear appropriate personal protective equipment (PPE).
Confirm that the water main section is fully depressurized and isolated before attempting to install the DFP11 Underground Fire Hydrant.
3. Pre-Installation Checklist
Inspect the DFP11 Underground Fire Hydrant for any visible damage during transport or storage, paying attention to the flange face and the operation of the valve spindle.
Check that the hydrant type, size, and pressure rating match the municipal system requirements.
Verify that the hydrant interior and main valve seat are clean and free from debris.
Confirm that the mating underground pipe flange is properly aligned (vertical) and free from burrs or sharp edges. Ensure the correct surface box and access components are available for the final grade level.
4. Installation Procedure
Positioning: Install the DFP11 Underground Fire Hydrant ensuring it is vertically plumb and securely bolted to the underground flange connection, positioning the main valve below the frost line. Backfill the lower section carefully, ensuring appropriate bedding material is used to facilitate drainage around the valve body (if applicable).
Use the appropriate gasket suitable for the medium and operating conditions.
Align the hydrant precisely with the pipe flange and insert bolts, tightening them gradually and crosswise in incremental steps. Do not exceed the specified torque to prevent damage to the hydrant body or the underground pipe joint.
5. Post-Installation
Slowly open the upstream isolation valve to pressurize the hydrant, checking immediately for leaks around the flanged connection. Verify the operating spindle turns smoothly and the main valve seals completely when closed. Install the surface box cover to be flush with the final grade level, ensuring the operating key can access the spindle. Record the installation details, depth of burial, and final bolt torques for documentation purposes.
Proper maintenance extends the service life of the DFP11 Underground Fire Hydrant and ensures constant readiness for emergency use. Follow the guidelines below to maximize the longevity of this essential public safety asset.
1. Routine Operation
Visually inspect the DFP11 Underground Fire Hydrant surface box and lid regularly (e.g., quarterly) for visible damage or obstructions that might prevent emergency access. Operate the hydrant (full open to full closed) periodically using the standard key to ensure the main valve seats smoothly and the operating spindle moves freely.
2. Inspection Schedule
Monthly, check the area surrounding the surface box for signs of water leakage, which may indicate a failed main valve seal or a faulty spindle packing.
Quarterly, check the functionality of the operating spindle mechanism through the surface box, ensuring the key engages correctly.
Annually, perform a comprehensive inspection of the main valve seat and internal components by removing the spindle/bonnet assembly (after isolation).
3. Lubrication
The operating spindle threads and internal thrust bearings of the DFP11 Underground Fire Hydrant should be lubricated annually or bi-annually according to the manufacturer’s specifications. Use only approved, potable water-safe lubricants.
4. Seal and Gasket Replacement
Replace the operating spindle packing and internal seals immediately if external leakage is observed when the hydrant is pressurized and closed. The main valve seat disc should be replaced if consistent leakage is detected after fully closing the hydrant. Always isolate the hydrant from the main water line and fully bleed the pressure before performing any internal maintenance work.
5. Cleaning
Keep the interior of the surface box and the top of the operating spindle clean to prevent dirt ingress into the stem packing area. The underground body requires no external cleaning.
6. Storage and Spare Parts
Store spare parts (gaskets, operating spindles, surface boxes) in a dry, clean environment, away from direct sunlight and harsh chemicals. Maintain a detailed record of all inspections, flow tests, and repairs performed on the DFP11 Underground Fire Hydrant unit.
We prioritize quality at every stage of production to deliver durable, safe, and efficient products. Our continuous improvement and strict quality controls keep us at the forefront of the industry.
Our certifications prove our commitment to excellence and compliance with international standards, ensuring the safety and reliability of our products worldwide.
We continuously invest in innovation and quality to expand our certifications and meet evolving industry needs.
Frequently Asked Questions about the DFP11?
What are the main advantages of this valve?
The DFP11 Underground Fire Hydrant offers guaranteed high-volume water access while being fully protected from traffic impact, vandalism, and freezing due to its secure below-ground installation and robust main valve design.
Why should I choose this product?
This valve delivers outstanding performance in both sealing and durability, making it a dependable choice for demanding applications. Its straightforward design facilitates easy installation, offering flexibility during system design. With a wide range of material options, it meets the needs of various infrastructure projects, from municipal water networks to industrial facilities.
What is the function of the break-away flange on the DFP10 Ground Fire Hydrant?
The break-away flange is a safety feature that causes the upper barrel to shear off cleanly above the grade in the event of an impact (e.g., vehicle collision), preventing damage to the main valve and isolating the flow to prevent massive water loss.
How does the DFP11 Underground Fire Hydrant prevent freezing in cold weather?
The hydrant prevents freezing by incorporating an automatic drain valve located at the base. When the main valve is fully closed, this drain opens, allowing all standing water in the upper barrel to drain completely into the surrounding gravel base below the frost line.
Why is the fully buried design safer than a ground hydrant?
Its fully buried design is safer because it eliminates the risk of traffic impact damage, which can lead to uncontrolled water discharge and costly repairs. It also prevents tampering and unauthorized operation in public areas.
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