What safety procedure should an operator follow before starting a large reciprocating machine without unloaders?

The proper safety procedure to follow before starting a large reciprocating machine without unloaders is to open the suction valve and discharge bypass. This action ensures that the machine can operate safely without building excessive pressure, which could cause damage to the system or pose a risk to personnel. By opening the suction valve, the machine is allowed to draw in fluid properly, and the discharge bypass ensures that any fluid that would typically return to the discharge line can be redirected appropriately, preventing pressure build-up.

The need for this specific procedure becomes critical in preventing hydraulic lock or damage to the machine from operating under conditions it was not designed for, which can occur if the machine is started without providing an appropriate flow path for the fluid.

While checking oil levels is a vital part of routine maintenance and operational safety, it does not directly relate to preventing issues associated with starting the machine without unloaders. Similarly, closing all valves would lead to a risky situation, and running the motor without a load could be harmful if necessary bypasses and valves are not adjusted to ensure safe operation. It is essential to prioritize procedures that directly ensure safe operating conditions for large reciprocating machines.