High-Pressure Bleed Back Line to Prevent Overpressure in Tie-in from Compressed Gas System to Receiving Tank
Publication Date: 2005-Mar-22
The IP.com Prior Art Database
Figure 1 (which is taken from Figure 5A of US Patent No. 6,786,245 (Eichelberger et.al.) shows an example of a tie-in (5) from a compressed gas supply system (such as a fueling station for gaseous hydrogen) to a receiving tank. A valve (110) is used to control the flow in order to meet a desired fill rate. A pressure transmitter (114) directly measures the pressure in the piping downstream of valve 110 and in a hose (8). A three-way valve (199) is used to provide isolation at the end of hose 8 and also provides a connection to a vent system (6). The nozzle (22) connects to the receiving tank. The piping downstream of valve 110 can also be depressurized through vent system 6 by opening a valve (136); a check valve (104) is included to prevent flow from the vent system 6 entering the tie-in 5 from the compressed gas system. A pressure relief device (139) is provided to protect against overpressure of the tie-in 5; the discharge of this relief device is fed to the vent system 6 (not shown).
When compressed gas is fed from the supply system to the receiving tank, the pressure at the end of the filling process in tie-in 5 may approach the rated pressure of the system and near the pressure at which the pressure relief device 139 may lift. If the tie-in is first used early in the day and then isolated, the change in ambient temperature may be sufficient to caus...