May I ask whether a manual valve is also allowed to be installed at the root of the safety valve in accordance with the specifications?
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May I ask whether a manual valve is also allowed to be installed at the root of the safety valve in accordance with the specifications?
It is generally not recommended to install a manual valve at the base of a safety valve, although there is no mandatory requirement in the regulations. For equipment that operates continuously, one safety valve is installed along with a backup one, so that the safety valves can be inspected on schedule without disrupting operations. In such cases, a manual valve must be installed at the base of the safety valve; this manual valve should either be sealed with lead or locked open. Additionally, a record-keeping system for the safety valves should be established.
Appendix B of GB150.1-2011: Hand valves are generally not recommended for use; however, in cases where continuous operation facilitates maintenance, the set pressure can be taken as 1.05–1.1 times the operating pressure. The design pressure should be greater than or equal to this set pressure
How can maintenance be carried out without installing valves? It’s sufficient to lock them open or seal them with lead seals; this is the key point, and they can be installed on either end
No justification means no installation
In many designs, a manual valve is placed in front of the safety valve to facilitate maintenance. However, when the safety inspection authorities come for inspections, they may require that the handle of the manual valve in front of the safety valve be removed or sealed with wax.
Sure, a three-way ball valve can be used to prevent problems in case the safety valve fails and needs to be replaced or repaired.
Setting it is not allowed, but most safety supervision agencies accept system measures such as locking the valves
It is not recommended, but if two safety valves, one in use and one as a backup, must be installed, the main valve should be sealed with lead to prevent accidental closing or opening.
Which standard is it? I couldn’t find what you mentioned in Appendix B of GB150.1-2011 :(