Control valve packing

There is now a high-temperature resistant filler. I bought it recently.

Asbestos cannot be used; only fillers based on graphite can be employed at high temperatures

Graphite fillers include pure graphite and malleable graphite; their characteristics are as follows. It is recommended to use flexible graphite instead: lol Flexible graphite, also known as expanded graphite, is produced by using flake graphite as raw material and undergoing chemical treatment to form interlayer compounds. At high temperatures of 800–1000°C, the interlayer compounds turn into gas, causing the flake graphite to expand by about 200 times; this gives it properties such as good thermal conductivity and overcomes its brittleness, resulting in excellent sealing performance. Loose and porous, with elasticity. It remains stable chemically, does not decompose, deform, or age when operating under high temperature, high pressure, or radiation conditions. The emergence of flexible graphite marked the end of the old era in the field of chemical sealing. Compared to asbestos gaskets, flexible graphite has the following obvious advantages: – It is radiation-free and pollution-free. Flexible graphite does not contain any components harmful to the human body, whereas asbestos products pose a risk of radiation to humans and can also pollute the environment. 　　II. High-temperature resistance. The flexible graphite-reinforced composite gasket can withstand high temperatures of up to 1650°C; even if chemical equipment melts, it remains intact. At 500°C, the crystalline water within asbestos products decomposes, causing them to disintegrate and lose their effectiveness. 　　III. Wide range of applications. In addition to strongly oxidizing acids, flexible graphite can withstand most chemical media, including those used in radioactive applications; whereas asbestos products have poor compatibility and cannot be used with radioactive media. For some chemical towers, heat exchangers, etc., it is required that the connection points not be insulated, and flexible graphite can meet this requirement, while slate products cannot. 　　IV. It is easy and quick to use. The gasket coefficient of flexible graphite is only half that of asbestos products; in other words, to achieve the same sealing effect, much less force is required to tighten the screws. In addition to the aforementioned notable properties, flexible graphite also features excellent sealing capabilities, good compressibility and elasticity, as well as oxidation resistance. It possesses strong self-lubricating properties and plasticity, and at the same time has good electrical conductivity, a high specific gravity, and a high density. It can be used to manufacture various components such as gaskets for pipes and flanges in diesel engines, compressors, and other devices.

Ours has air at over 500 degrees – can we use that?

There’s no problem at all. Please fabricate one set to give it a try; for another set (for example, one consisting of 5 rings), use graphite filler, with graphite rings in the middle section (3 rings), and metal and graphite-wound rings at the top and bottom. This will prevent the filler gland from being too tight, which could otherwise cause damage to the graphite: lol

The medium is high-temperature air, which is relatively pure; therefore, flexible graphite gaskets and packing are sufficient.

PTFE is generally used; graphite packing is used for high temperatures, and those designed for high temperatures and pressures use ones with metal rings.