Should a manual valve be installed in front of the breather valve on the storage tank? Is it allowed to install? What about the safety valve?
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Should a manual valve be installed in front of the breather valve on the storage tank? Is it allowed to install? What about the safety valve?
By default, it is always turned on. It is mainly used for maintenance and inspections of safety valves; it would be troublesome if there were no shut-off valves for such maintenance and replacement!
But it seems there are regulations stating that hand valves are not allowed, for safety reasons
It is not mandatory to remove it; installation is allowed, but it must remain in operation at all times. The handwheel should be sealed with wax so that it cannot be moved under normal circumstances.
Storage tanks generally do not require valves; they usually have only one breather valve, and the pressure is relatively low. When the pressure exceeds a certain level, air is released to the outside. Safety valves, on the other hand, do require valves – there are backup valves in place, and in case of internal leaks, the manual valve serves to switch things around
Generally, there is no need to install manual valves; if your operating system requires it, they can be installed, with the manual valves remaining in the open position during normal operation.
A breather valve is generally not installed, while a safety valve should be installed to facilitate disconnection for testing.
A manual valve is generally not installed in front of the breather valve; although its installation is allowed, it must be sealed with lead. Manual valves can be installed before and after the safety valve to facilitate inspection, maintenance, and annual checks.
It is not recommended to install a manual valve in front of the safety valve, but standards do not prohibit its installation. If it is installed, it must be sealed with lead; in some organizations, the key is destroyed after sealing it. Appropriate procedures must be in place to ensure that the manual valve does not get closed accidentally during operation.
I know that a safety valve should be equipped with a manual valve and that its seal must be kept intact. I would like to ask: if a vent valve and a flame arrester are already in place, is it still necessary to have a safety valve as well? Do I need to set both?
Two concepts: Simply put, a safety valve is used in pressure vessels and pressure pipelines, while the material in such systems can only flow out, not in； A breathing valve is a safety device used in atmospheric pressure tanks; it helps to maintain the pressure inside such tanks at normal levels, reduces the evaporation losses of volatile liquids within the tanks, and protects them from damage caused by excessive pressure or vacuum. The internal structure of a breather valve consists of a low-pressure safety valve (i.e., the exhalation valve) and a vacuum valve (i.e., the inhalation valve). Two that are not used at the same time.