Copper prohibited for control valves
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Why is it required that copper be avoided in the actuators of general control valves and their pneumatic accessories?
Is it due to insufficient strength? I want to know that too
It depends on the type of factory; generally, factories that produce ammonia require copper-free conditions. Copper is widely used in many accessories for air separation control valves used in methanol or steel industries.
There’s no such rule, right? Petrochemical plants do not have such a requirement; currently, most pneumatic signal lines are still made of copper tubes with a plastic coating on the outside.
Could you describe in detail: what process media, what scenarios, etc.? A simple sentence, but analyzing it involves a wide range of aspects.
Copper pipes are commonly used for air supply pipes; white steel pipes are also available, but they are not easy to bend. Your situation requires consideration on a case-by-case basis. If the process medium reacts violently with copper, then copper must be avoided – not only in control valves but also in other equipment. Our factory produces pesticides and uses materials such as pyridine, methanol, and ethyl acetate; I haven’t heard of any ban on copper.
It can’t really be considered a ban; it’s just not very practical. The hardness and strength of copper don’t seem that good
Our phthalic anhydride plant uses stainless steel gas pipes, but the problem is that modifying them is extremely difficult
Copper is prohibited in valves and accessories because the medium flowing through them can cause corrosion of copper. The air in the area where this valve is located may contain small amounts of such medium, which can also affect copper-containing accessories; hence, the use of copper is prohibited. Like cables, which have an insulating layer; since the medium cannot be contacted, there is no need to prohibit the use of copper! Whether copper is prohibited or not is determined by the manufacturing process!
There are no regulations prohibiting the use of copper; the choice is mainly based on the process requirements. Nowadays, many factories use copper pipes for their gas supply lines, and even some filters are made of pure copper.