Issues regarding the media suitable for glass-lined equipment
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According to GB25025, glass-lined equipment is suitable for media that can be almost completely ionized in aqueous solutions (excluding fluoride ions), except for hydrofluoric acid, concentrated phosphoric acid (concentration > 30%, temperature ≥ 180°C), and strong bases (pH > 12, temperature > 100°C). Recently, I encountered a glass-lined equipment with an inner cylinder of DN1300 and a wall thickness of 18 mm; the medium stored in it contains chlorine, and the operating pressure is 0.6 MPa. Can glass-lined equipment still be used in such operating conditions?
I feel the pressure is a bit high; if there is stirring, leakage is very likely to occur
There is no stirring; the flanges of the glass-lined equipment are slip-on flanges, which obviously do not meet the requirements specified in the relevant standards
Too much chlorine is introduced into the glass-lined inner cylinder; generally, chlorine is used in small amounts at low pressure, and it is introduced below the liquid level of the material.
Glass-lined equipment can definitely be used, but slip-on flanges cannot be employed; instead, necked flanges should be used. If the equipment is of the open type, even the large flanges must be high-neck welded flanges
Clamps cannot be used for the equipment flanges; double-headed studs should be employed instead.
Chloromethane presents even more severe conditions than those you are dealing with, and the equipment required is very large; your current conditions are no problem； Regarding the issue of slip rings mentioned below, it is caused by inconsistencies among various standards. Enameled steel products are used in many high-hazard media; I have also encountered cases involving phosgene. The special nature of the enamel production process makes the use of slip ring flanges inevitable.
Do you know that if double-ended studs are used, long-neck welded flanges with bolt holes will be necessary, which means the flanges will be very large. Enameled equipment has to be put into a furnace for many heating cycles at around 900 degrees Celsius, and after so many cycles it becomes severely deformed. I have done what the original poster mentioned regarding the corresponding devices. 1. Enameled steel equipment can be used. 2. Large flanges are usually welded with long necks and connected using clamps, while small pipe ends still use slip-on flanges; this is determined by the special characteristics of enamelled steel equipment. If strict standards were followed, it would be impossible to manufacture such products, and inspection agencies are well aware of this.
There are no issues at all with glass-lined equipment; we have many units of such equipment that can operate at a pressure of 1.2 MPa.