GB/T 50114-2010Standard for heating, ventilation and air conditioning drawings (English PDF)

2.1 Graph line

2.1.1 The basic width b and line width group of the drawing line shall be determined according to the proportion, category and usage method of the drawing.

2.1.2 The basic width b should be 0.18, 0.35, 0.5, 0.7, 1.0mm.

2.1.3 When only two line widths are used in the drawing, the line width group should be b and 0.25b. The line width groups of the three line widths should be b, 0.5b and 0.25b, and should meet the requirements in Table 2.1.3.

Note. It is not suitable to use a line width of 0.18 and thinner for drawings that require miniature

2.1.4 In the same drawing, the thin lines of different line width groups can uniformly use the thin lines of the smallest line width group.

2.1.5 The line types and their meanings used in HVAC professional drawing should comply with the provisions in Table 2.1.5.

2.1.6 Custom graphs and their meanings can also be used in the drawings, but they should be clearly stated, and their meanings should not conflict with this standard.

2.2 Scale

2.2.1 The general plan and the proportion of the plan should be consistent with the leading specialty of project design, and the rest can be selected according to Table 2.2.1.

3.1 Water and steam pipelines

3.1.1 Water and steam pipelines can be distinguished by line type or code. The codes of water and steam pipelines should be adopted according to Table 3.1.1.

3.1.2 The self-defined codes of water and steam pipelines should not contradict the provisions of Article 3.1.1 of this standard, and should be explained on the corresponding drawings.

3.1.3 The legends of water and steam pipeline valves and accessories should be adopted according to Table 3.1.3.

3.2 Duct

3.2.1 The air duct code should be adopted according to Table 3.2.1.

3.2.2 The self-defined air duct code should not contradict the provisions of Table 3.2.1 of this standard, and should be explained on the corresponding drawings.

3.2.3 The legends of air ducts, valves and accessories should be adopted according to Table 3.2.3-1 and Table 3.2.3-2.

3.3 HVAC equipment

3.3.1 The legend of HVAC equipment should be adopted according to Table 3.3.1.

3.4 Control devices and instruments

3.4.1 The legends of control devices and instruments should be adopted according to Table 3.4.1.

4.1 General provisions

4.1.1 The design drawings of each project and each stage shall meet the corresponding design depth requirements.

4.1.2 The numbers of the professional design drawings should be independent.

4.1.3 In the same set of engineering design drawings, the drawing line width group, legend, symbols, etc. should be consistent.

4.3.3 The piping system diagram may not be drawn according to the axonometric projection method if it does not cause misunderstanding.

4.3.4 The basic elements of the piping system diagram should correspond to the plan and section diagram.

4.3.5 The system diagrams of water and steam pipelines and ventilation and air-conditioning pipelines can be drawn with single lines.

4.3.6 The overlapping and dense places of pipelines in the system diagram can be drawn by disconnection. Disconnections should be indicated by the same lowercase Latin letters, and thin dashed lines can also be used to connect them.

4.3.7 For the design of outdoor pipe network engineering, it is advisable to draw the general plan of the pipe network and the longitudinal section of the pipe network.

4.3.8 The schematic diagram may not be drawn according to the scale and projection rules.

4.3.9 The basic elements of the schematic diagram should correspond to the plan view, section view and piping system diagram.

4.4 System number

4.4.1 When there are two or more different systems such as heating, ventilation and air conditioning in one project design, the system numbers shall be carried out.

4.4.2 The HVAC system number and entrance number shall consist of system code and sequence number.

4.4.3 The system code is represented by uppercase Latin letters (see Table 4.4.3), and the sequence number is represented by Arabic numerals, as shown in Figure 4.4.3.When a system branches, the drawing method in Figure 4.4.3(b) can be used.

4.4.4 The system number should be marked on the system manager.

4.4.5 For the vertical piping system arranged vertically, the vertical pipe number shall be marked (Fig. 4.4.5). If it does not cause misunderstanding, only the serial number can be marked, but it should be clearly different from the building axis number.

4.5 Pipeline elevation, pipe diameter (pressure), dimensioning

4.5.1 In drawings where the vertical dimension cannot be marked, the elevation shall be marked. Elevation should be in m and should be accurate to cm or mm.

4.5.2 The elevation symbol shall be represented by a right-angled isosceles triangle. When there are many standard floors, only the relative elevation to the floor (ground) slab of this floor may be marked (Figure 4.5.2).

4.5.3 If the marked elevation of water and steam pipes is not specified, it shall be expressed as the pipe center elevation.

4.5.4 When marking the outer bottom or top elevation of water and steam pipes, the words "bottom" or "top" should be added before the numbers.

4.5.5 The marked elevation of the rectangular air duct shall indicate the elevation of the pipe bottom; the marked elevation of the circular air duct shall indicate the elevation of the pipe center. When this method is not used for marking, it shall be explained.

4.5.6 The specification of welded pipes for low-pressure fluid transmission shall be marked with nominal diameter or pressure. The mark of the nominal diameter shall consist of the letter "DN" followed by a numerical value expressed in millimeters; the code of the nominal pressure shall be "PN".

4.5.7 For seamless steel pipes, spiral seam or straight seam welded steel pipes, copper pipes, and stainless steel pipes used for conveying fluids, when the outer diameter and wall thickness need to be indicated, it should be expressed as "D (or) outer diameter × wall thickness". When it does not cause misunderstanding, the nominal diameter can also be used to express.

4.5.8 The outer diameter of plastic pipes should be indicated by "de".

4.5.9 The cross-sectional size of the circular air duct shall be expressed in diameter "", and the unit shall be mm.

4.5.10 The cross-sectional size of the rectangular air duct (air duct) shall be expressed in "A×B". "A" should be the side length dimension of the projection plane of the view, and "B" should be the other side dimension. The unit of A and B should be mm.

4.5.11 The elevation of the pipeline without slope requirement in the plan may be marked in brackets after the section size of the pipeline. If necessary, the words "bottom" or "top" should be added before the elevation number.

4.5.12 The specification of the horizontal pipeline should be marked on the top of the pipeline; the specification of the vertical pipeline should be marked on the left side of the pipeline. For pipes represented by double lines, their specifications can be marked in the outline of the pipe (Figure 4.5.12).

4.5.13 When the inclined pipe is not within the 30° range shown in Figure 4.5.13, its pipe diameter (pressure) and size shall be marked on the oblique upper side of the pipe in parallel. If the method in Figure 4.5.13 is not used for marking, it can be marked with lead lines.

4.5.14 See Figure 4.5.14 for the specification marking method of multiple pipelines.

4.5.15 Refer to Figure 4.5.15 for the representation of tuyere.

4.5.16 Dimensions in the drawings shall be carried out in accordance with the relevant provisions of the current national standards.

4.5.17 If the positioning dimensions and elevations of continuously arranged equipment or pipelines need to be marked on the plan and section drawings, there should be at least one error-free section (Fig. 4.5.17).

4.5.18 The radiator installed on the wall shall indicate the installation height.

4.5.19 The dimensioning of equipment processing (manufacturing) drawings shall be carried out in accordance with the relevant provisions of the current national standard "Mechanical Drawing Dimensioning Method" GB 4458.4.Welds shall be carried out in accordance with the relevant provisions of the current national standard "Size, Proportion and Simplified Representation of Weld Symbols in Technical Drawings" GB 12212.

4.6 Drawing methods of pipe turning, branching, overlapping and dense places

4.6.1 Refer to Figure 4.6.1 for the drawing method of single-line pipeline turning.

4.6.2 See Figure 4.6.2 for the drawing method of double-line pipeline turning.

4.6.3 See Figure 4.6.3 for the drawing method of single-line pipe branch.

4.6.4 The drawing of the branch of the double-line pipeline is shown in Figure 4.6.4.

4.6.5 Refer to Figure 4.6.5 for the drawing method of the air supply pipe turning.

4.6.6 Refer to Figure 4.6.6 for the drawing method of the return air duct turning.

4.6.7 When the pipes in the plan view and section view need to be disconnected due to overlap and density, the method of disconnection shall be adopted (Fig. 4.6.7).

4.6.8 When the pipeline is interrupted in this drawing and transferred to (or introduced from) other drawings, the number of the drawing to (or from) should be indicated (Figure 4.6.8).

4.6.9 Refer to Figure 4.6.9 for the drawing method of pipeline crossing.

4.6.10 Refer to Figure 4.6.10 for the drawing method of pipeline spanning.