Certification: UL certification/ FM approval
Standard: Manufactured according to ASME B16.3, B16.14 (Malleable iron castings) or EN 10242 standard.
Temperature: -20℃ to 200℃.
Working pressure: 1.6 MPa to 2.5 MPa (approx 232 psi – 362 psi).
Surface Finish: Hot-dip galvanized / Electro-galvanized / Yellow-zinc plated / Black.
Thread Standard: Compliant with ISO 7/1 (BSPT) or NPT standard.
Malleable Iron Backnut is hexagonal nuts with female threaded connection, and it is used to tighten nipple or other pipe joint, so to avoid slippage.
This product is a malleable iron threaded locknut, a key pipe fitting used for locking, fixing, anti-loosening and anti-leakage in pipeline systems. It is mainly used with male threaded fittings and full thread nipples to fasten, position and enhance sealing, ensuring stable transmission of media such as water, oil, gas and steam.
Are you looking for a pipe locking accessory with firm locking, high strength and corrosion resistance? Our malleable iron Backnut Fig 310 BSPT is made of high-quality material through high-temperature annealing forging, with dense internal structure and high thread precision, capable of withstanding working pressures up to 1.6Mpa (16kg), effectively solving the problems of loosening and leakage at pipe joints. The surface is treated with uniform anti-rust coating, which is continuous and burr-free, with high locking fit, greatly improving the stability of pipeline connection and service life of the product.
The product is available in various nominal diameters from DN15 (1/2″) to DN100 (4″) and offers multiple surface treatment options such as natural and yellow-zinc plated. It can be widely used in various working conditions including fire protection, water supply, gas, chemical industry, and plumbing installation.
| SIZE | A (MM) | S (MM) | PCS/CTN. | |
| 1/2” | DN15 | 9 | 29 | 700 |
| 3/4” | DN20 | 10 | 36 | 500 |
| 1” | DN25 | 11 | 45 | 400 |
| 1 1/4” | DN32 | 11 | 56 | 300 |
| 1 1/2” | DN40 | 12 | 63 | 240 |
| 2” | DN50 | 13 | 77 | 160 |
| 2 1/2” | DN65 | 15 | 93 | 60 |
| 3” | DN80 | 18 | 109 | 50 |
| 4” | DN100 | 21 | 137 | 40 |
Intended Use:
Fire Protection Systems: Used for locking and anti-loosening of fire sprinkler pipe networks, full thread nipples and male threaded fittings, suitable for wet or dry fire protection pipe networks.
Commercial Buildings: Applied in locking and fixing of joints in air conditioning pipelines and water supply and drainage systems in banks, hotels and shopping malls.
Industrial Plants: Suitable for anti-loosening and sealing of pipeline joints conveying non-strongly corrosive media such as steam, coal gas and compressed air.
Residential Plumbing: Used for locking and positioning of male threaded joints, valves and fittings in home decoration water circuit modification to prevent loosening and leakage.
Compatibility:
Perfectly compatible with galvanized steel pipes, black steel pipes, full thread nipples and male threaded fittings.
Must be used with PTFE tape or oiled hemp for thread sealing.
Can be used together with elbows, tees, caps, unions and other fittings of the same specification.
Installation Guide:
1.Inspection: Before installation, check the internal and external surfaces of the Backnut Fig 310 BSPTfor sand holes and cracks, ensure threads are complete without breakage.
2.Cleaning: Remove iron chips and dirt from the pipe ends.
3.Assembly: First screw the Backnut Fig 310 BSP Tin to the male threaded fitting/pipe, then install the butt joint fitting, and finally lock the Backnut Fig 310 BSP Tin reverse.
4.Tightening: Tighten evenly with a wrench with moderate force to avoid cracking the fitting, and ensure no looseness or leakage at the joint.
Maintenance Tips:
1.Inspection Cycle: It is recommended to visually inspect the Backnut Fig 310 BSPT every six months, especially at threaded connections, checking for signs of rust, looseness or leakage.
2.Cleaning Method: Wipe the surface dust with a clean, damp cloth. For rust removal, use a wire brush to clean and then apply anti-rust paint.
3.Replacement Cycle: Generally, if there is no mechanical damage or severe corrosion, it can be used for over 10 years. If the Backnut Fig 310 BSPT has thread slipping, deformation or corrosion, replace it immediately.
Product List:
Steel Pipe: Match with standard galvanized steel pipes of the same specification (e.g., DN25, DN50).
Pipe Hangers/Supports: Provide matching U-bolts, hanger rods for fixing pipeline direction.
Other Fittings: Full thread nipples, street elbows, caps, unions, female elbows.
Sealing Materials: High-quality PTFE tape or liquid pipe sealant.
Combining these with our hot-dip galvanized steel pipes and seismic bracing systems builds a sturdy, durable, and code-compliant complete pipeline system. This ensures the pipeline does not loosen and fluid delivery is uninterrupted during a fire or emergency.
OEM is available. We can customize the product according to your specific requirements, including logo printing and packaging design.
The MOQ is 500 pieces. For customized products with special sizes or surface treatments, the MOQ may vary.
After order confirmation and receipt of the advance payment, we will arrange production. Generally, the products can be ready for shipment within 15-20 working days. Once dispatched, we will notify you and provide all necessary documents for customs clearance.
All products are 100% new and undergo strict quality inspections, including pressure testing and dimensional checks, before delivery. We use sturdy wooden crates or cartons to ensure the products are well-protected during transportation.
Yes, we provide detailed installation instructions in English and other major languages. Our technical support team is also available for online consultation and guidance if needed.
Sales Inquiry:
Provide contact information for sales inquiries.
Email: [email protected]
Phone: +86 13012223295
If you have any questions regarding product installation, commissioning, operation or maintenance, please contact our technical support team for professional assistance:
Email: [email protected]
