Issues with LPG tank drain pipes
Thread Content
According to Article 9.3.5 of GB51142-2015, a short pipe should be used to connect the two valves at the tank’s drain outlet, and anti-freezing measures should be taken. Question: Why is a short pipe used between the two valves, and what is the purpose of this? Is it necessary to add a safety valve between the two valves? If it’s in the south, are freeze protection measures necessary?
I haven’t studied the specifications in detail, but I think a small check valve (DN15 or DN20) should also be installed on the short pipe to facilitate the inspection of the drainage situation. The waste discharged is mainly water, and there is no need to install a safety valve between the two valves. Whether anti-freezing measures should be taken depends on local weather data – specifically, whether the lowest temperatures in winter fall below zero degrees. In some areas in the south, the temperatures also drop below zero in winter.
This standard applies to gas stations, not to petrochemical enterprises. Please check whether it is applicable to your own company
The petrochemical regulations also have similar requirements when connecting intermittently used utility pipes with process pipes, requiring the installation of inspection valves
What about the tank drain outlet that the original poster is discussing?
LPG requires sealed waste discharge, but in practice it is all discharged directly