Regarding the types of valves on flue gas pipelines

If a 1% internal leakage rate is acceptable, then a ventilation butterfly valve, which is commonly used in flue gas pipelines, can be chosen. There is no seal between the butterfly disc of such a valve and its body, which is why it has a 1% internal leakage rate. If no internal leakage is allowed, then a triple-eccentric butterfly valve should be selected. The price of a triple-eccentric butterfly valve is much higher than that of a ventilation butterfly valve. Is the operating temperature at your site 440°C? At 440°C, it is best to use 304 material. WCB can theoretically withstand temperatures of up to 450°C, but for safety reasons, it is recommended to choose 304

A high-temperature flue gas butterfly valve can be selected, with the valve disc and seat made of 2520 stainless steel~~

I wonder if there are any with a lower price.

The price is ridiculously low; I wouldn’t dare to use it~ Hehe

For valve bodies operating at 440°C, it is not necessary to use material 2520; material 304 is sufficient. Material 2520 is required only when the instantaneous temperature reaches 1000°C or the normal temperature is 800°C, whereas for this temperature range, material 304 is adequate

For a cast-steel ventilation butterfly valve with a diameter of DN1000, the price is around 10,000 yuan; those made of 304 stainless steel cost a little over 20,000 yuan. After all, given such a large diameter, the price can’t be too low. If it is too cheap, one should be cautious, as the dimensions of the valve body may not be standard. In April this year, I had a client who needed a ventilation butterfly valve capable of withstanding a maximum operating temperature of 750°C; the valve body in question was made of 2520 material. The price I quoted was about one-third higher than that of another supplier from whom he purchased the valve. Within less than two months of using it, the valve stopped closing properly and couldn’t be opened anymore. Upon disassembly, it was found that the disc had deformed. It was only after communicating with him on-site that I learned the thickness of the disc there was 6 mm, while the thickness of the valve flange was 12 mm. The thickness of the valve body couldn’t be measured on-site, so it wasn’t provided. But just from these two thicknesses, it’s clear that the valve there was too thin. Here, the thickness of the disc is 12 mm, and the thickness of the valve flange is 18 mm. In the end, they had no choice but to purchase the valve from us again. Your required temperature isn’t too extreme, but it’s important to pay attention to quality – one shouldn’t solely focus on low prices. It’s necessary to consider the cost-performance ratio; remember, cheap products are often of poor quality. Everyone is in business, and no one is stupid. If several suppliers offer similar prices, then there’s no problem. But if one supplier offers a significantly lower price, there’s definitely something wrong with that product.

Thank you for your analysis and guidance; quality comes at a price, and we will take everything into consideration.

You’re welcome. You can also ask several other manufacturers for quotes and consider them all before making a decision.