[Haichuan Chemical Valve Management] Series Posts -- Specifications for Safety Valve Tears (Tear Holes, Drain Holes) and Their Bases

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Proper management of valves is the foundation for stable operation. Everyone is welcome to engage in discussions and share insights on this series of posts: 【HaiChuan Chemical Valve Management】 series of posts: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5719309 ---------------------------------------------------------------- Disclaimer: The content contained in this article is intended solely for technical exchange and reference purposes only; it does not constitute any form of professional engineering advice, design basis, or operational guidance. -----------------------------------------------------------------------------------1. GB/T 12243-2021 \"Safety valves with direct spring loading\": Clause 4.4.5 of this standard specifies that, in order to prevent liquid from accumulating below the sealing surface of the valve seat, safety valves used for steam and liquid media must be equipped with drain bolt holes (i.e., weep holes) at the lowest point where liquid can accumulate. For safety valves with a nominal diameter greater than 65 mm, the diameter of the tear hole should not be less than 9.5 mm ； For those with a nominal diameter not exceeding 65 mm, the tear hole diameter should not be less than 6.5 mm. If the safety valve does not have its own drain hole or no drainage outlet is used, a weep hole must be provided at the bottom of the pipe near the outlet of the safety valve. 2. GB50517-2010 (2023 edition) \"Code for Acceptance of Construction Quality of Metal Piping in Petrochemical Projects\": Article 8.6.2 requires that when the outlet pipe of a safety valve leads vertically upward, a weep hole with a diameter of 6 mm to 10 mm shall be provided at the lowest point of the outlet pipe; the inspection shall be carried out through visual inspection and measurement. 3. SH/T 3012-2011 \"Code for Design of Layout of Metal Piping in Petrochemical Industries\": Clause 10.2.9 stipulates that on the outlet pipe of a safety valve that leads directly upward to the atmosphere, a drainage hole (tear hole) with a diameter of Φ6~Φ10 mm should be provided near the elbow at the lower end ； The weep holes on the steam pipes must be led to a safe location. At the same time, the specification emphasizes that the placement of tear holes should avoid conflicts with pipe supports, welds, and other such elements, to ensure smooth drainage. 4. HG/T 20570.2-1995 \"Installation and Selection of Safety Valves\": It requires that a tear hole with a diameter of φ6～φ10mm be installed at the lowest point of the outlet pipe of the safety valve used to discharge gaseous media; a wire mesh should be attached to the pipe opening to prevent birds from nesting there, and the discharge outlet must be cut so that its opening faces upward, away from the operation platform and pedestrian pathways.