Water filling of spherical tank
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Question: Why can’t a fixed connection be used for the water injection line of the water injection pump in liquid hydrocarbon spherical tank assemblies? According to the specifications, a semi-fixed connection should be used; however, when it is not convenient to make adjustments using a fixed connection on site, a blind flange should be installed between the fire protection piping and the LPG pipeline. Yet this approach is not recommended – why?
By saying “a blind flange should be added between the fire protection pipeline and the LPG system,” do you mean adding a blind flange at the valve where the fire protection pipeline is connected to the LPG tank? It is likely to prevent internal leakage of the valve, so that LPG can enter the fire protection system through the fire hoses, creating potential hazards.
A semi-fixed connection is advisable; it is relatively convenient and does not cause oil leakage. Generally, the pressure of liquid hydrocarbons is higher than that of fire water in fire protection pipelines under normal conditions. If LPG is connected to the fire protection pipeline in a fixed manner without the use of blind flanges, any leakage in the valves can easily lead to LPG entering the fire protection pipeline. Dangerous**.
To prevent leaks, it is necessary to stop liquefied hydrocarbons from leaking into the fire protection pipes through fixed pipelines, as that would be very dangerous.
According to Sinopec’s corporate regulations, fixed connections with blind flanges are not recommended. One of the reasons I understand for this is that in an emergency, removing the blind flanges requires a lot of effort and time; according to those on site, it takes around 15 minutes to complete the task (I can’t remember exactly the time; it was a project carried out 3 years ago). In the event of an accident, such a response time is simply unacceptable. . .
We use quick-connect fittings, which facilitate installation and removal and eliminate the risk of cross-contamination between water lines and liquefied gas lines
According to the specifications for the water injection lines of liquid hydrocarbon sphere tank assemblies, semi-fixed connections are used so that pipes can be connected quickly for water injection in emergency situations. When fixed connections are used on-site and it is not convenient to make adjustments, blind flanges should be installed between the fire protection pipelines and the LPG. These blind flanges are intended to prevent LPG from mixing with the fire protection water, but their use is not recommended, as there is a risk that in an emergency you might need to remove them, which could delay the process of filling the system with water
The water injection line for the pump in the liquid hydrocarbon spherical tank assembly uses a semi-fixed connection, which prevents cross-contamination of materials when not in use, while ensuring timely connection when it is needed – ready for use!
There is no need to use blind plates; generally, the water inlet pipes for fire-fighting water and liquefied gas tanks are equipped with dual valves, and proper sealing of these valves ensures isolation. Of course, it is also possible to install two valves at the outlet of the fire pump, with a pressure gauge and a drain valve installed in between at an interval of about 30 centimeters. During regular inspections, it is important to monitor pressure changes – an increase in pressure indicates that one of the water inlet valves is leaking, making operation and identification straightforward
Yes, to prevent material from mixing. Thank you:handshake