I. Common Methods for Sealing Ductile Iron Pipe Leaks

Depending on the shape of the leak (hole, crack), the amount of leakage, and the pipe pressure, the following methods can be used:

1. Emergency and Temporary Treatment (Small Leak, Low-Pressure Environment)

Leak-Sealing Agent/Steel Plastic: Similar to "quick-drying cement for pipes," this material solidifies quickly upon contact with water. It is suitable for leaks with low pressure. First, clean the pipe surface, then press the sealant onto the leak and secure it in place, allowing it to fully cure.

Stainless Steel Clamp/Pipe Repair Clamp (Small): For smaller holes, a stainless steel clamp with a sealing gasket can be used to secure it directly to the leak. This is a classic mechanical repair method.

Welding Repair:

Brass Welding/Soldering: If the pipe pressure is low and the water supply can be completely shut off, brazing can be used to repair cracks. However, this requires high skill and can cause some damage to the pipe itself. Cold welding: Repairs are performed using special cold welding fluids and materials. This method minimizes thermal impact on the pipe, but is often used for low-pressure or temporary repairs.

Note: The above methods are primarily temporary or emergency measures and are not recommended as long-term solutions for critical main pipes, especially those bearing high pressure.

2. Reliable and Permanent Treatment (Recommended for Main Pipes)

For leaks in ductile iron main pipes, the most professional and reliable method is to use pipe repair clamps.

2. Advantages of Using Pipe Repair Clamps

Pipe repair clamps (or leak repair clamps), especially those specifically designed for ductile iron pipes, are the most commonly used and effective tools in modern pipe repairs. Their advantages are significant:

1. Efficient and Fast, Significantly Reducing Water Outage Time
Pipe repair clamps are designed with "speed" in mind. Installation requires no complex welding or tapping processes; simply clean the surface, align the position, and tighten the bolts.

The entire leak repair process can typically be completed within 1-2 hours, significantly minimizing the impact on customer water use compared to traditional methods like welding and taping, which require lengthy maintenance. 2. No Special Skills Required, Easy to Use

Installing the pipe repair clamp does not require specialized welders or advanced technicians; ordinary maintenance personnel can operate it with minimal training, reducing reliance on manual skills.

3. Safe, Reliable, and Excellent Sealing Performance

The pipe repair clamp features a one-piece, high-strength ductile iron housing, offering high mechanical strength and capable of withstanding the pipe's original operating pressure or even higher.

The built-in, high-quality, food-grade rubber seal (typically NBR or EPDM) is extremely elastic and corrosion-resistant. Under the tightening force of the bolt, it adheres tightly to the pipe surface, forming a permanent seal and preventing secondary leaks.

4. Wide Applicability

It effectively repairs various types of damage: longitudinal and transverse cracks, holes, pinholes, and joint leaks.

A variety of specifications are available, suitable for pipes of varying diameters (DN80-DN2000 and even larger).

5. Operates under pressure (in some cases)

If the leak is minor and the pressure allows, some emergency repairs can be performed without completely shutting off the water supply. Instead, installation can be completed while maintaining a certain level of system pressure, further improving repair efficiency.

6. Corrosion-resistant, durable, and long-lasting

Pipe repair clamps are typically treated with an anti-corrosion treatment (such as epoxy resin spraying), and their rubber seals are also resistant to aging. Their service life matches the pipe itself, ensuring a single repair and long-term peace of mind.

7. Economical

While the purchase cost of a single pipe repair clamp may be higher than a package of leak-proofing agent, its overall cost-effectiveness is the highest considering its shorter installation time, lower labor costs, minimal indirect losses associated with no water outage, and permanent effectiveness.

3. Pipe Repair Clamp Installation Steps

1. Shut off the water supply and release the pressure: Close the valves in front of and behind the leak and drain the water from the pipe.

2. Surface Preparation: Thoroughly clean the pipe surface around the leak, removing rust, dirt, and old coatings to expose the metal body, ensuring a smooth and clean surface. 3. Place the seal: Align the included rubber seal with the leak.
4. Install the pipe repair clamp: Close the upper and lower halves of the repair clamp onto the pipe, covering the leak and the seal.
5. Tighten the bolts: Use a torque wrench to tighten all bolts gradually and evenly, alternating diagonally, until the specified torque value is reached, ensuring even pressure distribution.
6. Open the valve for pressure testing: Slowly open the valve, restore the water supply, and observe the pipe repair clamp for leaks. Once there are no leaks, backfill the gap and complete the work.

The housing is typically made of metals such as ductile iron and carbon steel, which are corrosion-resistant and high-strength. It can last the same life as the original pipe, eliminating the need for frequent repairs. Baoshuo brand carbon steel half joints are available in a variety of rubber materials, including NBR, EPDM, FKM, and silicone rubber. The half joint body is available in Q235 carbon steel and 304 and 316L stainless steel.

The following are Baoshuo brand oil-resistant pipe repair clamps, high-temperature-resistant pipe repair clamps, acid- and alkali-resistant pipe repair clamps, stainless steel pipe repair clamps, high-pressure-resistant pipe repair clamps, and large-diameter pipe repair clamps.

4.Summary and Recommendations

For leaking ductile iron pipes, we recommend using a professional ductile iron repair clamp. It is a modern repair solution that combines efficiency, reliability, safety, and cost-effectiveness, and is particularly suitable for critical pressure piping systems such as municipal water supply and industrial water distribution.

For temporary emergency measures, you can use leak sealants or small pipe repair clamps, but a permanent repair should be planned as soon as possible. Traditional welding is riskier and requires demanding skills and conditions, so it is gradually being replaced by pipe repair clamps.

Before any repair, ensure you accurately assess the leak and select qualified repair products that match the pipe size and pressure rating.