Color coding for chemical pipelines

According to British standards, chlorine is delivered through yellow pipes.

I know the color codes for ordinary water, steam, nitrogen, and hydrogen. I admire LZ!

Actually, it’s mainly sufficient to mark the utility pipes and special pipes. In our company, circulating water is marked in green, vacuum drainage in white, wastewater in black, production air compressors and instrument air compressors in blue, and fire protection systems in red. Pipes used for insulation or cooling are usually coated with anti-rust paint; after that, they are insulated or cooled, and there is no color marking on their outer layer, and so on. Of course, the corresponding storage tanks are also marked in different colors, with various styles depending on each company’s specific products and intermediates. This post was last edited by sisism on 2007-4-26 at 21:06.]

SH-J 43-1991 Colors and Markings on the Surfaces of Equipment and Piping in Petrochemical Enterprises

1.3 Equipment identification instructions: 1.3.1 Equipment identification used in production workshops – The signboard is 110 mm long and 90 mm wide； “\"Shiyao Group\" shall be in black font size 2, \"Visheng Pharmaceutical (Shijiazhuang) Co., Ltd.\" shall be in bold black font size 2, while all other text shall be in black Song typeface size 3. The suspension mechanism should be installed 10 mm above the top edge of the plate, with circular holes of 3 mm in diameter made on each side at a distance of 20 mm from that edge. For the specific identification format, see Figure 1. 1.3.2 Laboratory instrument labeling: The label is 90 mm in length and 60 mm in width ； “\"Shiyao Group\" shall be in black font size 2, \"Visheng Pharmaceutical (Shijiazhuang) Co., Ltd.\" shall be in black font size 3; all other text shall be in black Song typeface, size 3. The suspension mechanism should be installed 10 mm above the top edge of the plate, with circular holes of 3 mm in diameter made on each side at a distance of 20 mm from that edge. For the specific identification format, see Figure 2. 1.3.3 Identification for standby, operating, sealed, under maintenance, and scrapped equipment: The identification tag is 100 mm in length and 50 mm in width, with blue background and white text. See Figure 3 for details. 1.3.4 The material of the signboard is aluminum-plastic panel or stainless steel. 1.4 Location of fixed asset identification tags for equipment: Each workshop shall select an appropriate placement location based on the actual conditions of various pieces of equipment. The specific requirements are as follows: a. For equipment with a production status tag, the fixed asset identification tag should be affixed next to the production status tag. b. For equipment without a production status label and that has a flat surface, attach the fixed asset label to that flat surface. c. Others: For example, install brackets at the pipe connections for pumps, and attach fixed-asset identification tags to those brackets. It is also eye-catching, easy to operate, and oriented toward the main inspection routes. When the equipment is under maintenance, maintenance workers must hang a “Maintenance in Progress” sign at the maintenance site. 1.5 Management of device identification: Device identification is uniformly established and issued by the Equipment Department. Each workshop is responsible for hanging the identification tags (a two-person verification system is required for hanging – one person operates while another verifies), and ensuring that these tags remain clean and in good condition. The workshop or department in question shall compile monthly records of damaged or newly added equipment, submit requests to the Equipment Department, which will then handle the production and customization of the tags. 2. Pipeline identification 2.1 To facilitate the differentiation of pipelines carrying various media, different colors should be applied to the outer protective layer of the pipelines; the coloring method is monochromatic. a. For pipes with a DN50 diameter (including the thickness of the insulation layer), the labeling shall use font sizes of 35 (50) or 80; the arrow shall be 50 mm in total length and 10 mm in width, with its head being an isosceles triangle having an apex angle of 30 degrees and a height of 30 mm. b. For pipes with DN50–125, use size 150 characters; the total length of the arrow is 75 mm, its width is 15 mm, and the head portion is an isosceles triangle with a vertex angle of 30 degrees and a height of 35 mm. c. For DN125–150 pipes, use size 150 arrows; the total length of the arrow is 150 mm, the width is 20 mm, and the tip forms an isosceles triangle with an apex angle of 30 degrees and a height of 70 mm. d. For DN150–250, use font size 250; the total length of the arrow is 150 mm, its width is 20 mm, and its head is an isosceles triangle with an apex angle of 30 degrees and a height of 70 mm. For e.DN250 and above, 400-point font is used. The total length of the arrow is 150 mm, its width is 35 mm; the head of the arrow is an isosceles triangle with a vertex angle of 45 degrees and a height of 70 mm. The pipe identifier is located in a prominent position on the operation main plane or on the pipe, in the color Orange 204 or Scarlet 101. All fonts are bold sans-serif. To keep pipes of different specifications in the same row neat, the same style of font and arrows can be used. The medium name should be placed behind the flow arrow (e.g.: circulating water →). The discharge hose must indicate the type of medium. 2.2 Location of pipe markings: They should be marked at pipe elbows, where pipes pass through walls, and in areas where pipes are densely arranged making identification difficult; such markings must be placed on a straight pipe section at least 500 mm away from the elbow ； If the distance between two elbows is less than 1000 mm, the middle position should be chosen, and the identification of the pipes that are directly connected to the equipment should be marked in a visible location. 2.3 Management of pipeline markings: Pipeline markings are established uniformly by the Equipment Department; each workshop is required to apply these markings in accordance with the specified standards, and any damage detected must be repaired promptly.

Is this uniform across the country, or do different design institutes have different *practices?

I suggest that those friends upstairs, since they’ve taken the effort to provide color coding standards, please also provide the corresponding implementation standards and their sources; one must have evidence when making statements

It depends on the standards used; of course, different standards yield different results

I’ve seen several versions of this already