What causes the loss of pipeline pressure

The fluid flowing through the piping system will be subject to pressure drop due to the flow through the throttle valve and the control valve. Stop the flowing fluid and the pressure in the pipeline will increase to the upstream pressure.

When fluid flows from a high-pressure source into a low-pressure system, there is an obvious place where the system will withstand higher pressure by activating the isolation valve. This different point is called the norm "pressure break" point. Piping valves and fittings upstream of this point must be designed to withstand higher pressures.

The design of piping and equipment must take into account the possible source pressure that the system may withstand. This means that the isolated pipe section of the downstream pressure relief device must be designed to withstand the upstream pressure. Typically, this "design" pressure will be set by the set pressure of the upstream pressure relief device or the pressure generated by the upstream source (pump, compressor, or wellhead). Pressure loss sometimes occurs on the isolation valve, and the placement of the isolation valve must be carefully considered in the design of the pressure piping system.

The check valve will leak or even fail to open, it allows pressure to pass from the high-pressure side to the low-pressure side. (In the event of a leak, a check valve should still be used to minimize backflow, but the check valve cannot be relied upon to prevent overpressure.)

Among them: the control valve (including the independent regulator) can be in the open or closed position, whichever way allows the pipe section to withstand the pressure.

The shut-off valve can be placed in the open or closed position, no matter which position produces the pressure.

High-pressure sensors cannot provide adequate overvoltage protection. The pressure relief valve operates steadily due to the high reliability of its design. (In emergency services, the operator needs to install a backup pressure relief valve on the main pressure relief device to improve reliability).

When checking the rules, the easiest way is to start with the main relief valve (designed for plugging) and trace the upstream pipeline (including all branches) to the plugging valve or control valve. Assuming the valve is closed, the pipeline flows upstream (including all branches) to the next pressure relief valve. The pipeline from the shut-off valve to the upstream relief valve or pressure source should be rated according to the pressure set by the relief valve. The pressure at each position of each branch upstream of the shut-off valve should be set to the pressure, at which position it can be isolated from the downstream relief valve.
check valve