What is good for pipes used to transport chlorine gas?
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What is suitable for pipes used to transport chlorine gas? Can PP-R be used?
For transporting chlorine with a water content of 400 ppm or less, ordinary carbon steel pipes are used; for wet chlorine at very low pressures, non-metallic pipes are employed.:lol
It seems that those in the chemical industry think things more complicatedly. We are a water treatment plant that uses chlorine for disinfection; the chlorine is in the form of liquid chlorine in bottles, which is then vaporized and delivered – with basically no moisture contained in it. The amount of chlorine is also very low; we used PVC in the past, and now we’re considering whether it’s possible to switch to another type of plastic pipe. It’s so cheap and not prone to corrosion, but I’m not sure if PP-R (random copolymerized polypropylene) will work
1. For dry chlorine gas, 20-grade carbon steel pipes can generally be used, but low-alloy steel pipes such as 16Mn are preferred; TIG welding is employed, and the welds are heat-treated to relieve stress. 2. Wet chlorine gas must be handled using nickel-based material steel pipes, or PTFE-lined pipes.
Our pipelines for transporting chlorine are under negative pressure. Many factories use PVC, and there’s no problem with that; it’s just that the material cannot be used for too long. We use 4-inch PVC pipes, and they have been in use for 7 years now. Given that PVC is brittle, has low strength, and a short lifespan, we are considering whether we can switch to PP-R (polypropylene)
Supporting the above claim is quite professional.
Our company uses PVC pipes for wet chlorine and seamless carbon steel pipes for dry chlorine.
Follow in the footsteps of those who came before you. If anything goes wrong when you use PP-R pipes, it will be your fault. In chemical pipelines, can PVC really be used for handling such highly toxic substances? Hehe, am I thinking too much? Negative pressure also means there is pressure present, so it can’t be designed based on normal pressure. PVCl used in the chemical industry seems to operate at a pressure of 1 MPa; however, for highly toxic applications, the pressure level needs to be increased. Therefore, it is best to use carbon steel pipes; lining them with PVC is also an option. This advice is for reference only.
PVC/FRP composite pipes are acceptable; we have used them before. Coating them with fiberglass can increase their strength. It is a more advanced process than using PVC lining with carbon steel. Moreover, fiberglass is also corrosion-resistant.
It’s not clear which is more stable to chlorine gas, PVC or PP-R pipes. Although, in theory, dry chlorine gas is being transported, special situations involving water ingress cannot be ruled out.
PP-R cannot be used. Because the strong oxidizing property of chlorine will quickly damage the pipes. I recommend FRP-lined PVC pipes.
Dry chlorine is generally transported using carbon steel pipes, while wet chlorine is more often conveyed through PVC pipes. Although PVC pipes age easily, their cost is still much lower than that of nickel pipes!
Random PP copolymers exhibit strong resistance to acids, bases, alcohols, low-boiling hydrocarbon solvents, and many organic chemicals. At room temperature, PP copolymers are practically insoluble in most organic solvents. Moreover, when exposed to soap or soap alkaline solutions. In aqueous reagents and alcohols, they do not suffer from environmental stress cracking damage like many other polymers. When in contact with certain chemicals, especially liquid hydrocarbons. Chlorinated organic compounds and strong oxidizing agents can cause surface cracks or swelling. Non-polar compounds are generally more easily absorbed by polypropylene than polar compounds.
For safety reasons, it is best to use a carbon steel pipe lined with a plastic pipe.