Regarding the installation of safety valves and the issue of pre-cut valves for safety valves
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I would like to ask the experienced experts on this forum about the standards regarding the installation of safety valves – what are the specific regulations that dictate where such valves should be installed. What are the standard clauses that specify when a front shut-off valve should be installed in such situations? For the safety valve of the low-pressure vinyl chloride intermediate tank, it was stated during the last inspection that the shut-off valve in front of the safety valve must be locked to prevent it from being closed arbitrarily. During this inspection, it was stated that the front shut-off valve must not be locked, so as to ensure it can be closed in emergency situations. They are all the experts’ suggestions for improvement; I don’t know how to make the necessary changes. Please ask the experienced experts for guidance.
So when your experts speak, you can politely ask them for the basis on which they are making those statements.
Experts with law enforcement powers, oh :(
Experts on law enforcement powers. . What’s the matter? They mentioned it politely – how can they still issue you a fine right away;P
““To prevent it from not being able to be shut down in an emergency.” Where did this expert come from? If it can be shut down in an emergency, then what’s the need for a safety valve? Shutting the valve in an emergency – is that meant to create a bomb?:
The standards regarding the installation of safety valves are as follows: Regulations for the Technical Supervision of Fixed Pressure Vessels TSG21-2016 7.2.3.1 Safety Valves 7.2.3.1.1 Inspection contents and requirements (4) If a stop valve is installed between the safety valve and the discharge outlet, it is necessary to check whether the stop valve is in the fully open position and whether its seal is intact； (This clause demonstrates that when a root valve is installed in front of a safety valve, effective measures such as lead seals or locks must be used to ensure that the valve remains fully open.) 9.1.3 Requirements for the installation of overpressure relief devices: (1) Overpressure relief devices should be installed in the gaseous space above the liquid level of the pressure vessel, or on pipes connected to the gaseous space of the pressure vessel ； The safety valve should be installed vertically ； (This item indicates the installation location of the safety valve.) (4) It is generally not advisable to install a stop valve between the overpressure relief device and the pressure vessel ； To enable online calibration of safety valves, a burst disc device can be installed between the safety valve and the pressure vessel ； For pressure vessels that contain media with extremely high, high, or moderate toxicity, explosive media, corrosive or viscous media, or valuable media, in order to facilitate the cleaning and replacement of safety valves, a stop valve may be installed between the overpressure relief device and the pressure vessel, provided that it is approved by the person in charge of safety management at the using unit and that reliable preventive measures are put in place. During normal operation of the pressure vessel, the stop valve must remain fully open (either sealed with lead or locked); its structure and diameter must not interfere with the safe operation of the overpressure relief device ； (This clause specifies under what circumstances a root stop valve can be installed in front of the safety valve)
In accordance with the requirements of major regulatory standards and relevant product standards. For example, GB/T12337.
This post was last edited by xlxuiin on 2021-5-13 at 13:22. 5.0.2 Safety valves must be installed in containers that fall under any of the following conditions: 5.0.2.1 Independent pressure systems (separated from other systems by isolation valves). This system refers to those that are entirely gas-phase, entirely liquid-phase, or have a gas connection; 5.0.2.2 Containers where there is no safety valve at the source of the pressurized material; 5.0.2.3 Containers and pipes whose design pressure is lower than that of the pressure source; 5.0.2.4 Outlet pipes of positive-displacement pumps and compressors; 5.0.2.5 Containers that experience overpressure due to the accumulation of non-condensable gases; 5.0.2.6 When there is a shut-off valve or control valve on the outlet pipe of a heating furnace, a safety valve should be installed upstream of such valve; 5.0.2.7 Areas where overpressure occurs as a result of process accidents, automatic control failures, power failures, fires, or utility failures; 5.0.2.8 Areas where liquids experience thermal expansion due to valves being closed at both ends; 5.0.2.9 Steam outlet pipes of condensing turbines; 5.0.2.10 In some cases, a safety valve should be installed on the inlet pipe of a pump due to leaks in the pump’s outlet check valve; 5.0.2.11 Other locations where safety valves should be installed.
Which idiot expert said that such a requirement is equivalent to killing people?