To replace old steel heating pipes with copper pipes, you will first need to turn off the water supply to the heating system. Next, use a pipe cutter to remove the old steel pipes and clean the ends of the copper pipes that will be replacing them. Then, use soldering equipment to connect the copper pipes in place of the old steel pipes. Finally, test the new copper pipes for leaks before turning the water supply back on. It is recommended to consult a professional plumber if you are not experienced with this type of work. **

Soft steel pipes are not recommended for heating applications because they are not able to withstand the high temperatures and pressure that are typically involved in heating systems. Soft steel pipes are more prone to corrosion and can easily deform or burst under the stress of heating. It is better to use pipes made of materials specifically designed for heating applications, such as stainless steel or copper, to ensure safety and efficiency. **

To separate two jammed steel pipes, you can try using a lubricant such as WD-40 to help loosen them. If that doesn't work, you can also try using a pipe wrench or a pair of pliers to grip the pipes and twist them in opposite directions to break the jam. If the pipes are still stuck, you may need to apply heat using a torch to expand the metal and make it easier to separate them. Remember to take safety precautions when using heat and always wear protective gear. **

There are several methods for connecting steel pipes without welding. One common method is using threaded fittings, which involves screwing the pipes together using threaded connectors. Another method is using compression fittings, which involve using a compression nut and ferrule to create a tight seal between the pipes. Additionally, push-fit fittings can be used, which simply require pushing the pipes into the fitting to create a secure connection. These methods provide a reliable and efficient way to connect steel pipes without the need for welding. **

One can buy 15m thick steel pipes from specialized steel suppliers or manufacturers that produce and distribute industrial-grade steel pipes. These suppliers can be found online or through industrial directories. Additionally, construction and engineering companies may also have access to sources for purchasing such specialized steel pipes. It is important to ensure that the supplier meets the necessary quality and safety standards for the intended use of the steel pipes. **

Copper pipes with stainless steel connections are generally safe for use in plumbing systems. Stainless steel is a durable and corrosion-resistant material, making it a suitable choice for connecting copper pipes. However, it is important to ensure that the connections are properly installed and sealed to prevent any potential leaks or issues. Additionally, it is always recommended to consult with a professional plumber to ensure that the materials and connections used are appropriate for the specific plumbing application. **

Drainage pipes are typically more stable than KG pipes because they are designed to handle the weight of soil and water above them. Drainage pipes are usually made of materials such as PVC or corrugated metal, which are strong and durable. KG pipes, on the other hand, are typically used for non-pressure applications and may not be as sturdy as drainage pipes. Overall, drainage pipes are better suited for underground applications where stability and durability are important factors. **

Steel heating pipes do not rust on the inside because they are typically filled with hot water or steam, which creates an environment that is not conducive to rust formation. The high temperature of the water or steam helps to prevent the formation of rust by accelerating the evaporation of any moisture that may be present inside the pipes. Additionally, the constant flow of hot water or steam can help to remove any potential rust-causing impurities from the inside of the pipes, further reducing the likelihood of rust formation. Finally, many heating systems are treated with corrosion inhibitors to further protect the pipes from rust. **