Startup operation of a reciprocating press

There is no need to close the inlet and outlet, but some refineries start up by closing the outlet; the compressor is started under pressure, and it’s sufficient to set the load to zero.

The machines here often fail to start; pressing the switch does nothing. The manager said that it’s necessary to release pressure before starting the machine, and the entrances and exits must be closed in order to do so

Under normal circumstances, it is fine to start a reciprocating machine under pressure, but it must be started with no load; otherwise, it will cause the motor to shut down.

The loading valve is broken; when operating under load, the piston rod might bend

Under normal circumstances, it is prohibited to close the inlet valve when starting a reciprocating machine, unless the compression ratio is not high and both the suction and discharge circuits are fully open； Starting under pressure: by this, the author means starting with pressure at the outlet or at the inlet. The principle for starting rotating equipment is to do so at the lowest possible load; therefore, there is no need to consider starting with pressure at the outlet. As for starting with pressure at the inlet, it is acceptable as long as the inlet pressure remains within the specified range ； When a compressor shuts down due to interlock, it is first necessary to determine what caused the interlock to activate; once the fault is resolved, the compressor can be restarted. Hope this can help you

False alarms due to electrical issues; I mean that high pressure in the engine body makes it difficult to start the engine

In either case, the machine should be started and stopped with no load.

1. Reciprocating compressors are basically driven by motors, so in principle, starting them under load is definitely not allowed. I’m not sure if by starting the machine under pressure you mean starting it while it’s under load If only system pressure is considered, a reciprocating compressor must be within a certain pressure range in order to start properly; it will not start if the pressure is below that level ； 2. Whether the machine can be started immediately after an interlock shutdown depends on the conditions that triggered the interlock; factors such as machine vibration, shaft displacement, lubricating oil conditions, and rotor temperature certainly prevent restart. If the shutdown was caused by a brief power interruption, it should be possible to resume operation in a short time ； 3. Before starting the reciprocating machine, the inlet valve must be opened; the outlet valve should be selected depending on the operating conditions. There are several situations I have encountered: First, the outlet valve is closed while the bypass valve beside the engine body is open. After starting the engine, the load is increased gradually, and at the same time the bypass valve is slowly closed. Once the outlet pressure reaches the required level, the outlet valve is gradually opened to integrate it into the system slowly ； Another type features a return line; both the inlet and outlet are open, which allows for direct increase in load, with the return line used to regulate flow.