GB 17888.3-1999 Mechanical safety - Fixed means of access to machinery and industrial equipment - Part 3: Stairs, steps and guardrails
Some standard content:
GB17888.3—1999
This standard is equivalent to ISO/DIS14122-3:1996 in terms of technical content. The main differences between them are as follows: 1. The introduction in ISO/DIS14122-3 is rewritten in accordance with domestic conditions. 2. In the "referenced standards" chapter of ISO/DIS14122-3, 17 European standards or draft standards are listed, and most of these referenced standards are not mentioned in the technical content of the standard. Therefore, in the referenced standards of this standard, only a few corresponding national standards mentioned in the text of the standard are listed, and the rest are deleted. This standard is the third part of the series of standards for fixed facilities for access to machines and industrial equipment. This series of standards consists of four standards, and the other three standards are:
Part 1: Selection of fixed facilities for access between two levels. Part 2 Working platforms and passages.
Part 4: Fixed vertical ladders.
This standard was proposed by the State Bureau of Machinery Industry. This standard is under the jurisdiction of the National Technical Committee for Machinery Safety Standardization. The responsible drafting unit of this standard is the Mechanical Science Research Institute. Participating drafting units are: Jilin Province Labor Protection Science Research Institute, China Standardization and Information Classification and Coding Research Institute.
The main drafters of this standard are: Ma Xianzhi, Shi Junwei, Xiao Jianmin, Zhang Mingxu, Li Qin, Yongcai, Xiao Wei. 62
GB 17888.3-1999
ISO Foreword
This standard was developed by CEN/TC114 Working Group 17. It is the third part of the Machinery Safety Standard. The parts of this standard are: Part 1: Selection of fixed facilities for access between two levels. Part 2: Working platforms and passages.
Part 3: Stairs, steps and guardrails.
Part 4: Fixed ladders.
The use of non-metallic materials (wood, composite materials, etc.) does not change the application of this standard. Permanent means of access to machines and industrial plants" 63
National Standard of the People's Republic of China
Safety of machinery
Permanent means of access to machines and industrial plants-Part 3: Stairways, stepladders and guard-rails0 Introduction
GB17888.3-1999
This standard is an improvement and refinement of the basic safety requirements proposed in 6.2.4 "Safe access to machinery" of GB/T15706.2-1995.
1 Scope
This standard specifies the safety requirements and preventive measures applicable to straight stairways and steps. The definition of stairs and steps is shown in GB 17888.1.
This standard sets out requirements for guardrails, stairs, steps, platforms, work platforms, passages and places where people enter machines and industrial equipment. This standard does not apply to places where the public can enter. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T15706.1-1995 Basic concepts and general principles for the safety of machinery Part 1: Basic terms and methodology GB/T15706.2-1995
Basic concepts and general principles for the safety of machinery Part 2: Technical principles and specifications GB17888.1-1999 Mechanical safety of fixed access to machines and industrial equipment Part 1: Fixed access between two levels
GB17888.2-1999 Mechanical safety of fixed access to machines and industrial equipment Part 2: Working platforms and passageways GB17888.4-1999 Mechanical safety of fixed access to machines and industrial equipment Part 4: Fixed vertical ladders 3 Definitions
This standard uses the following definitions.
3.1 Stairway and step ladder A series of continuous horizontal surfaces (treads or flight platforms) of different heights that can be walked on. Its components are shown in Figure 1 and explained in 3.1.1 to 3.1.4.
3.1.1 Climbing height The vertical distance between the base and the flight platform (H in Figure 1). Approved by the State Administration of Quality and Technical Supervision on October 18, 199964
Implemented on October 1, 2000
3.1.2 Flight
The uninterrupted portion between two flight platforms. 3.1.3 Going
GB 17888.31999
The horizontal distance between the protruding edges of two adjacent steps (g in Figure 1). H—rising height g—step; e-headroom; h—height of riser (of tread); p-length of platform; r—overlap part zα—slope—width, s1—diagonal line Figure 1 Parts of stairs and steps
3.1.4 Headroom
The minimum vertical distance after removing all obstacles (such as beams, pipes, etc.) above the diagonal line (e in Figure 1). 3.1.5 Landing
The horizontal resting plane at the end of a flight (force in Figure 1). 3.1.6 Overlap
The part of the tread that can be extended horizontally to cover the previous plane (in Figure 1). 3.1.7 Pitch of the stairway or stepladderThe angle between the diagonal line and its projection on the horizontal plane (α in Figure 1). 3.1.8 Riser height
The vertical distance between two adjacent tread surfaces (h in Figure 1). 3.1.9 step
Horizontal surface on which one walks when walking up or down a staircase or flight of steps. 3.1.10 step nosing
Top edge in front of the step.
3.1.11 straight flight stairwayA stairway with a straight line of ascent.
3.1.12 stringer
Side frame member supporting the step.
3.1.13 width
Distance between the two sides of the step (1 in Figure 1). 3.2 guard-rails
Device to prevent accidental falls or accidental entry into a hazardous area. It can be installed on stairs, steps or flight platforms, operating platforms, or in passageways. Typical parts of guard-rails are shown in Figure 2 and defined in 3.2.1 to 3.2.5. 65
3.2.1 Handrail
GB 17888. 3-1999
①-handrail, ②-crossbar, ③-kickboard ④-stanchion, ?-base Figure 2 Examples of parts of typical guardrail structure
The top component that is intended to be grasped by hand to support the body. It can be used alone or as the upper part of the guardrail (① in Figure 2). 3.2.2 Kneerail
A guardrail component installed parallel to the handrail, which can provide additional protection for the passage of the body (② in Figure 2). 3.2.3 Stanchion
A vertical structural component of the guardrail that fixes the guardrail to the operating platform, stairs, etc. (in Figure 2). Other components of the guardrail (handrail, crossbar, baffle are fixed to this component.
3.2.4 Self closing The guardrail part of the gate that is easy to open. When the gate is not held open by a person, it will automatically close with the help of gravity or springs.
3.2.5 Toe-plate
The solid part at the bottom of the guardrail set to prevent objects from falling from the floor plane (③ in Figure 2). 4 General requirements and/or measures on materials and dimensions 4.1 The selection of materials, dimensions and construction modes of each component shall meet the safety requirements of this standard. 4.2 The performance of the materials used or after treatment shall be resistant to corrosion caused by the environment. 4.3 Certain parts that may come into contact with the user shall be designed not to cause injury or obstruction (such as avoiding sharp corners, welding burrs, rough edges, etc.).
4.4 Each pedal and stair platform shall have good anti-slip properties. 4.5 Opening or closing the movable part (door) shall not cause further danger to the user or other people nearby (such as shearing or accidental falling).
4.6 To ensure safety, the accessories, hinges, supports, bearings and mountings used for assembly shall have sufficient rigidity and stability. 4.7 The size of the pedals and frames shall be designed so that they can withstand the expected load. 4.8 The frame load used in the industrial field can be selected between 1500N/m2 (occasional passage or no load) and 4000N/m2 (frequent passage or load passage).
4.9 The protruding edge of each pedal shall be able to withstand a load of 1500N. If the width 1 is less than 1200mm, the load acts on an area of 100mm×100mm; if the width 1 is greater than or equal to 1200mm, a load of 1500N shall be added at every symmetrical 600mm. 4.10 The deflection of the frame and the treads shall not exceed 1/300 of the span. 5 Safety requirements and/or facilities for stairs
5.1 The step g and the height of the riser h shall satisfy the following formula:66
Note: α is between 30° and 38°.
GB 17888. 3 --1999
600≤g2h≤660
5.2 The overlapping part r of the treads shall not be less than 10mm. 5.3 The height of the risers shall be consistent on the same flight. In the case where this height cannot be observed between the starting plane and the first step, it may be reduced by up to 15%. This height may also be increased if it is proven to be reasonable, for example in the case of some movable machines. 5.4 The uppermost step shall be at the same level as the flight platform (see Figure 3). h
Figure 3 Position of the uppermost step
5.5 The clearance height e shall be at least 2300mm. b)
5.6 For stairs for single-person passage, the clear width between the two inclined beams or guardrails should be at least 600mm, preferably 800mm. 5.7 When the stairs are frequently subjected to the crossing of several people at the same time, the width should be increased to 1200mm. This width is necessary when the stairs can be used as an evacuation route for personnel. 5.8 The rising height H of a flight of stairs should generally not exceed 3m. In special cases, this height should not exceed 4m. Otherwise, an additional flight platform is required before reaching another flight of stairs. The length of the flight platform should be at least 800mm and greater than or equal to the width of the stairs.
6 Safety requirements and/or facilities for stairs
6.1 The maximum height h of the vertical board should be 250mm, and the minimum step g should be 100mm. 6.2 The clear width between the two inclined beams or guardrails should be between 500 and 800mm, preferably 600mm. 6.3 When there is insufficient space around the machine or in the industrial equipment and it is not possible to use these values, other values may be used. In this case, additional safety facilities should be provided to ensure safe use (such as preventing the protruding edge of the tread from slipping). 6.4 The height of the risers should be consistent in the same flight. In the case where it is not possible to avoid this height between the starting plane and the first step, the height can be reduced. If it is justified, the height between the starting plane and the first step can be increased, such as in the case of some movable machines.
6.5 The clearance height e should be at least 2300mm. 6.6 The rising height H of a flight should not exceed 3m. If this height is exceeded, a flight landing needs to be added before reaching another flight. The length of the flight landing should be at least 600mm and not greater than the width of the step. 7 Safety requirements and/or facilities for guardrails
7.1 Horizontal guardrails (see Figure 4)
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Figure 4 Example of horizontal guardrails
GB 17888.3—1999
7.1.1 Guardrails shall be provided wherever there is a risk of falling. 7.1.2 Guardrails shall be installed when the height from which a possible fall may exceed 500 mm. 7.1.3 Guardrails are not required if the distance between the operating platform and the machine frame or wall is less than 200 mm and the protection of the frame is equivalent to that of the guardrails. However, when the distance between the operating platform and the adjacent frame is greater than 30 mm, a toeboard shall be provided. 7.1.4 The minimum height of the handrail shall be 1100 mm. 7.1.5 The guardrail shall include at least one intermediate crossbar or some other equivalent protection. The free space between the handrail and the crossbar and between the crossbar and the toeboard shall not exceed 500 mm.
7.1.6 When vertical poles are used instead of horizontal poles, the maximum horizontal spacing between vertical poles is 180mm. 7.1.7 Skirting boards with a minimum height of 100mm should be placed no more than 10mm from the base surface. 7.1.8 The distance between the axes of each support should be limited to 1500mm. If this distance is exceeded, special attention should be paid to the fixing strength of the support and the fixing device.
7.1.9 In the case of interrupted handrails, the maximum clear distance between two sections of guardrails should not exceed 120mm. If there is a large opening, self-closing doors should be used.
Self-closing doors should have handrails and crossbars of the same height as the handrails and crossbars of the guardrails (for the exit section of the ladder, see GB 17888.4).
7.2 Guardrails for stairs and steps (see Figure 5). 7.2.1 Stairs should contain at least one handrail. Stairs with a width greater than or equal to 1200mm and all steps should have two handrails. 7.2.2 When the rise of a staircase exceeds 500 mm and there is a lateral spacing of more than 200 mm on the outside of the diagonal beam, a guardrail should be attached to its side.
Figure 5 Example of stair-passageway connection guardrail
7.2.3 The vertical height of the handrail should be at least 900 mm. In order to ensure a safe grip, the diameter of the handrail should be a circular cross-section between 25 and 50 mm or an equivalent cross-section that is easy to grasp by hand. 7.2.4 The guardrail should include at least one crossbar or some equivalent device. The clear spacing between the handrail and the crossbar and between the crossbar and the diagonal beam should not exceed 500 mm.
7.2.5 There should be no obstacles within 100 mm of the handrail, except for the lower end face of the fixed support. 7.3 Strength criteria
GB 17888. 3-1999
Figure 6 Position of the deflection gauge
Guardrails shall be supported so that a lateral load greater than or equal to Fmin is applied along the most unfavorable part of the handrail without permanent deformation and the maximum deflection does not exceed 30 mm.
Fmin = 300 N/m × L
L is the maximum distance between the axes of two adjacent pillars (L in Figure 6, unit: m). 8 Inspection of safety requirements and/or facilities
8.1 General toilet
The facilities specified may be checked by visual inspection, measurement or calculation. 8.2 Test of guardrails
The load F.min = 300 N/m × L is applied to the handrail step by step, without impact, and horizontally. The deflection (f1, f) produced along the center line is measured by the deflection gauge positioned horizontally as shown in Figure 6. 8.2.1 Pre-loading stage
Apply load Fmin vertically to the pillar for 1 min as shown in Figure 7, then remove the guardrail load and reset the meter to zero. 8.2.2 First measurement
Apply load Fmn for 1 min as shown in Figure 7.
The deflection f measured during loading should not exceed 30 mm. Fmin
Figure 7 First measurement
8.2.3 Second measurement
Apply load Fmin as shown in Figure 8.
The deflection measured during loading should not exceed 30 mm. After unloading, there should be no residual deformation.
17888.3—1999
Second measurement4 The uppermost step should be on the same level as the staircase platform (see Figure 3). h
Figure 3 Position of the uppermost step
5.5 The clearance height e should be at least 2300mm. b)
5.6 For stairs for single-person passage, the clear width between the two inclined beams or guardrails should be at least 600mm, preferably 800mm. 5.7 When the stairs are frequently crossed by several people at the same time, the width should be increased to 1200mm. This width is necessary when the stairs can be used as an evacuation route for personnel. 5.8 The rising height H of a staircase should generally not exceed 3m. In special cases, this height should not exceed 4m. Otherwise, an additional staircase platform is required before reaching another staircase. The length of the staircase platform should be at least 800mm and greater than or equal to the width of the stairs.
6 Safety requirements and/or facilities for stairs
6.1 The maximum height h of the riser should be 250 mm and the minimum step g should be 100 mm. 6.2 The clear width between two inclined beams or guardrails should be between 500 and 800 mm, preferably 600 mm. 6.3 When there is insufficient space around the machine or in the industrial equipment and it is not possible to adopt these values, other values may also be adopted. In this case, additional safety facilities should be provided to ensure safe use (such as preventing the protruding edge of the step from slipping). 6.4 The height of the riser should be consistent in the same flight. If it is impossible to avoid this height between the starting plane and the first step, the height can be reduced. If it is justified, the height between the starting plane and the first step can be increased, such as in the case of some movable machines.
6.5 The clearance height e should be at least 2300 mm. 6.6 The rising height H of a flight should not exceed 3 m. If this height is exceeded, an additional flight platform is required before reaching another flight. The length of the stair platform should be at least 600 mm and not greater than the width of the step. 7 Safety requirements and/or facilities for guardrails
7.1 Horizontal guardrails (see Figure 4)
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Figure 4 Example of horizontal guardrails
GB 17888.3—1999
7.1.1 Guardrails should be provided whenever there is a risk of falling. 7.1.2 Guardrails should be installed when the height of a possible fall exceeds 500 mm. 7.1.3 Guardrails are not required if the distance between the operating platform and the machine frame or wall is less than 200 mm and the protection of the frame is equivalent to that of the guardrails. However, when the distance between the operating platform and the adjacent frame is greater than 30 mm, a toeboard should be provided. 7.1.4 The minimum height of the handrail should be 1100 mm. 7.1.5 The guardrail should include at least one intermediate crossbar or some other equivalent protection. The free space between handrails and crossbars and between crossbars and skirting boards should not exceed 500mm.
7.1.6 When vertical bars are used instead of crossbars, the maximum horizontal spacing between the vertical bars is 180mm. 7.1.7 Skirting boards with a minimum height of 100mm should be placed no more than 10mm from the base surface. 7.1.8 The distance between the axes of each support should be limited to 1500mm. If this distance is exceeded, special attention should be paid to the fixing strength of the support and the fixing device.
7.1.9 In the case of interrupted handrails, the maximum clear spacing between two sections of guardrails should not exceed 120mm. If there is a large opening, self-closing doors should be used.
Self-closing doors should have handrails and crossbars of the same height as the handrails and crossbars of the guardrails (for the exit section of the ladder, see GB 17888.4).
7.2 Guardrails for stairs and steps (see Figure 5). 7.2.1 Stairs shall include at least one handrail. Stairs with a width greater than or equal to 1200 mm and all steps shall have two handrails. 7.2.2 When the rise of a staircase exceeds 500 mm and there is a lateral spacing of more than 200 mm on the outside of the diagonal beam, guardrails shall be attached to its side.
Figure 5 Example of stair-passageway connection guardrail
7.2.3 The vertical height of the handrail shall be at least 900 mm. To ensure a safe grip, the diameter of the handrail shall be a circular cross-section between 25 and 50 mm or an equivalent cross-section that is easy to grasp by hand. 7.2.4 The guardrail shall include at least one crossbar or some equivalent device. The clear spacing between the handrail and the crossbar and between the crossbar and the diagonal beam shall not exceed 500 mm.
7.2.5 There shall be no obstructions within 100 mm of the handrail, except for the lower end face of the fixed support. 7.3 Strength criteria
GB 17888. 3-1999
Figure 6 Position of the deflection gauge
Guardrails shall be supported so that a lateral load greater than or equal to Fmin is applied along the most unfavorable part of the handrail without permanent deformation and the maximum deflection does not exceed 30 mm.
Fmin = 300 N/m × L
L is the maximum distance between the axes of two adjacent pillars (L in Figure 6, unit: m). 8 Inspection of safety requirements and/or facilities
8.1 General toilet
The facilities specified may be checked by visual inspection, measurement or calculation. 8.2 Test of guardrails
The load F.min = 300 N/m × L is applied to the handrail step by step, without impact, and horizontally. The deflection (f1, f) produced along the center line is measured by the deflection gauge positioned horizontally as shown in Figure 6. 8.2.1 Pre-loading stage
Apply load Fmin vertically to the pillar for 1 min as shown in Figure 7, then remove the guardrail load and reset the meter to zero. 8.2.2 First measurement
Apply load Fmn for 1 min as shown in Figure 7.
The deflection f measured during loading should not exceed 30 mm. Fmin
Figure 7 First measurement
8.2.3 Second measurement
Apply load Fmin as shown in Figure 8.
The deflection measured during loading should not exceed 30 mm. After unloading, there should be no residual deformation.
17888.3—1999
Second measurement4 The uppermost step should be on the same level as the staircase platform (see Figure 3). h
Figure 3 Position of the uppermost step
5.5 The clearance height e should be at least 2300mm. b)
5.6 For stairs for single-person passage, the clear width between the two inclined beams or guardrails should be at least 600mm, preferably 800mm. 5.7 When the stairs are frequently crossed by several people at the same time, the width should be increased to 1200mm. This width is necessary when the stairs can be used as an evacuation route for personnel. 5.8 The rising height H of a staircase should generally not exceed 3m. In special cases, this height should not exceed 4m. Otherwise, an additional staircase platform is required before reaching another staircase. The length of the staircase platform should be at least 800mm and greater than or equal to the width of the stairs.
6 Safety requirements and/or facilities for stairs
6.1 The maximum height h of the riser should be 250 mm and the minimum step g should be 100 mm. 6.2 The clear width between two inclined beams or guardrails should be between 500 and 800 mm, preferably 600 mm. 6.3 When there is insufficient space around the machine or in the industrial equipment and it is not possible to adopt these values, other values may also be adopted. In this case, additional safety facilities should be provided to ensure safe use (such as preventing the protruding edge of the step from slipping). 6.4 The height of the riser should be consistent in the same flight. If it is impossible to avoid this height between the starting plane and the first step, the height can be reduced. If it is justified, the height between the starting plane and the first step can be increased, such as in the case of some movable machines.
6.5 The clearance height e should be at least 2300 mm. 6.6 The rising height H of a flight should not exceed 3 m. If this height is exceeded, an additional flight platform is required before reaching another flight. The length of the stair platform should be at least 600 mm and not greater than the width of the step. 7 Safety requirements and/or facilities for guardrails
7.1 Horizontal guardrails (see Figure 4)
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Figure 4 Example of horizontal guardrails
GB 17888.3—1999
7.1.1 Guardrails should be provided whenever there is a risk of falling. 7.1.2 Guardrails should be installed when the height of a possible fall exceeds 500 mm. 7.1.3 Guardrails are not required if the distance between the operating platform and the machine frame or wall is less than 200 mm and the protection of the frame is equivalent to that of the guardrails. However, when the distance between the operating platform and the adjacent frame is greater than 30 mm, a toeboard should be provided. 7.1.4 The minimum height of the handrail should be 1100 mm. 7.1.5 The guardrail should include at least one intermediate crossbar or some other equivalent protection. The free space between handrails and crossbars and between crossbars and skirting boards should not exceed 500mm.
7.1.6 When vertical bars are used instead of crossbars, the maximum horizontal spacing between the vertical bars is 180mm. 7.1.7 Skirting boards with a minimum height of 100mm should be placed no more than 10mm from the base surface. 7.1.8 The distance between the axes of each support should be limited to 1500mm. If this distance is exceeded, special attention should be paid to the fixing strength of the support and the fixing device.
7.1.9 In the case of interrupted handrails, the maximum clear spacing between two sections of guardrails should not exceed 120mm. If there is a large opening, self-closing doors should be used.
Self-closing doors should have handrails and crossbars of the same height as the handrails and crossbars of the guardrails (for the exit section of the ladder, see GB 17888.4).
7.2 Guardrails for stairs and steps (see Figure 5). 7.2.1 Stairs shall include at least one handrail. Stairs with a width greater than or equal to 1200 mm and all steps shall have two handrails. 7.2.2 When the rise of a staircase exceeds 500 mm and there is a lateral spacing of more than 200 mm on the outside of the diagonal beam, guardrails shall be attached to its side.
Figure 5 Example of stair-passageway connection guardrail
7.2.3 The vertical height of the handrail shall be at least 900 mm. To ensure a safe grip, the diameter of the handrail shall be a circular cross-section between 25 and 50 mm or an equivalent cross-section that is easy to grasp by hand. 7.2.4 The guardrail shall include at least one crossbar or some equivalent device. The clear spacing between the handrail and the crossbar and between the crossbar and the diagonal beam shall not exceed 500 mm. wwW.bzxz.Net
7.2.5 There shall be no obstructions within 100 mm of the handrail, except for the lower end face of the fixed support. 7.3 Strength criteria
GB 17888. 3-1999
Figure 6 Position of the deflection gauge
Guardrails shall be supported so that a lateral load greater than or equal to Fmin is applied along the most unfavorable part of the handrail without permanent deformation and the maximum deflection does not exceed 30 mm.
Fmin = 300 N/m × L
L is the maximum distance between the axes of two adjacent pillars (L in Figure 6, unit: m). 8 Inspection of safety requirements and/or facilities
8.1 General toilet
The facilities specified may be checked by visual inspection, measurement or calculation. 8.2 Test of guardrails
The load F.min = 300 N/m × L is applied to the handrail step by step, without impact, and horizontally. The deflection (f1, f) produced along the center line is measured by the deflection gauge positioned horizontally as shown in Figure 6. 8.2.1 Pre-loading stage
Apply load Fmin vertically to the pillar for 1 min as shown in Figure 7, then remove the guardrail load and reset the meter to zero. 8.2.2 First measurement
Apply load Fmn for 1 min as shown in Figure 7.
The deflection f measured during loading should not exceed 30 mm. Fmin
Figure 7 First measurement
8.2.3 Second measurement
Apply load Fmin as shown in Figure 8.
The deflection measured during loading should not exceed 30 mm. After unloading, there should be no residual deformation.
17888.3—1999
Second measurement7 The skirting board with a minimum height of 100mm should be placed no more than 10mm from the base surface. 7.1.8 The distance between the axes of each support should be limited to 1500mm. If this distance is exceeded, special attention should be paid to the fixing strength of the support and the fixing device.
7.1.9 In the case of interrupted handrails, the maximum clear distance between two sections of guardrails should not exceed 120mm. If there is a large opening, self-closing doors should be used.
Self-closing doors should have handrails and crossbars of the same height as the handrails and crossbars of the guardrails (for the exit section of the ladder, see GB 17888.4).
7.2 Guardrails for stairs and steps (see Figure 5). 7.2.1 Stairs should contain at least one handrail. Stairs with a width greater than or equal to 1200mm and all steps should have two handrails. 7.2.2 When the rise of a staircase exceeds 500 mm and there is a lateral spacing of more than 200 mm on the outside of the diagonal beam, a guardrail should be attached to its side.
Figure 5 Example of stair-passageway connection guardrail
7.2.3 The vertical height of the handrail should be at least 900 mm. In order to ensure a safe grip, the diameter of the handrail should be a circular cross-section between 25 and 50 mm or an equivalent cross-section that is easy to grasp by hand. 7.2.4 The guardrail should include at least one crossbar or some equivalent device. The clear spacing between the handrail and the crossbar and between the crossbar and the diagonal beam should not exceed 500 mm.
7.2.5 There should be no obstacles within 100 mm of the handrail, except for the lower end face of the fixed support. 7.3 Strength criteria
GB 17888. 3-1999
Figure 6 Position of the deflection gauge
Guardrails shall be supported so that a lateral load greater than or equal to Fmin is applied along the most unfavorable part of the handrail without permanent deformation and the maximum deflection does not exceed 30 mm.
Fmin = 300 N/m × L
L is the maximum distance between the axes of two adjacent pillars (L in Figure 6, unit: m). 8 Inspection of safety requirements and/or facilities
8.1 General toilet
The facilities specified may be checked by visual inspection, measurement or calculation. 8.2 Test of guardrails
The load F.min = 300 N/m × L is applied to the handrail step by step, without impact, and horizontally. The deflection (f1, f) produced along the center line is measured by the deflection gauge positioned horizontally as shown in Figure 6. 8.2.1 Pre-loading stage
Apply load Fmin vertically to the pillar for 1 min as shown in Figure 7, then remove the guardrail load and reset the meter to zero. 8.2.2 First measurement
Apply load Fmn for 1 min as shown in Figure 7.
The deflection f measured during loading should not exceed 30 mm. Fmin
Figure 7 First measurement
8.2.3 Second measurement
Apply load Fmin as shown in Figure 8.
The deflection measured during loading should not exceed 30 mm. After unloading, there should be no residual deformation.
17888.3—1999
Second measurement7 The skirting board with a minimum height of 100mm should be placed no more than 10mm from the base surface. 7.1.8 The distance between the axes of each support should be limited to 1500mm. If this distance is exceeded, special attention should be paid to the fixing strength of the support and the fixing device.
7.1.9 In the case of interrupted handrails, the maximum clear distance between two sections of guardrails should not exceed 120mm. If there is a large opening, self-closing doors should be used.
Self-closing doors should have handrails and crossbars of the same height as the handrails and crossbars of the guardrails (for the exit section of the ladder, see GB 17888.4).
7.2 Guardrails for stairs and steps (see Figure 5). 7.2.1 Stairs should contain at least one handrail. Stairs with a width greater than or equal to 1200mm and all steps should have two handrails. 7.2.2 When the rise of a staircase exceeds 500 mm and there is a lateral spacing of more than 200 mm on the outside of the diagonal beam, a guardrail should be attached to its side.
Figure 5 Example of stair-passageway connection guardrail
7.2.3 The vertical height of the handrail should be at least 900 mm. In order to ensure a safe grip, the diameter of the handrail should be a circular cross-section between 25 and 50 mm or an equivalent cross-section that is easy to grasp by hand. 7.2.4 The guardrail should include at least one crossbar or some equivalent device. The clear spacing between the handrail and the crossbar and between the crossbar and the diagonal beam should not exceed 500 mm.
7.2.5 There should be no obstacles within 100 mm of the handrail, except for the lower end face of the fixed support. 7.3 Strength criteria
GB 17888. 3-1999
Figure 6 Position of the deflection gauge
Guardrails shall be supported so that a lateral load greater than or equal to Fmin is applied along the most unfavorable part of the handrail without permanent deformation and the maximum deflection does not exceed 30 mm.
Fmin = 300 N/m × L
L is the maximum distance between the axes of two adjacent pillars (L in Figure 6, unit: m). 8 Inspection of safety requirements and/or facilities
8.1 General toilet
The facilities specified may be checked by visual inspection, measurement or calculation. 8.2 Test of guardrails
The load F.min = 300 N/m × L is applied to the handrail step by step, without impact, and horizontally. The deflection (f1, f) produced along the center line is measured by the deflection gauge positioned horizontally as shown in Figure 6. 8.2.1 Pre-loading stage
Apply load Fmin vertically to the pillar for 1 min as shown in Figure 7, then remove the guardrail load and reset the meter to zero. 8.2.2 First measurement
Apply load Fmn for 1 min as shown in Figure 7.
The deflection f measured during loading should not exceed 30 mm. Fmin
Figure 7 First measurement
8.2.3 Second measurement
Apply load Fmin as shown in Figure 8.
The deflection measured during loading should not exceed 30 mm. After unloading, there should be no residual deformation.
17888.3—1999
Second measurement
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