Mariner Mani

  Types of Maintenance Procedures 1)   Preventive or Scheduled Maintenance System It is famously known as the PMS or Planned Maintenance System. In this type of system the maintenance is carried out as per the running hours like 4000 hrs, 8000 hrs etc., or by the calendar intervals like 6 monthly, yearly etc. of the machinery. The maintenance is carried out irrespective of the condition of the machinery. The parts have to be replaced if it is written in the schedule, even if they can be still used. 2)  Corrective or Breakdown Maintenance In this system, maintenance is carried out when the machinery breaks down. This is the reason it is known as breakdown maintenance. This is not a suitable and good method as situations may occur wherein the machinery is required in an emergency. The only advantage of this system is that the working of machinery parts is used to its full life or until it breaks. This system might get costly as during breakdown several other parts may also get damaged. 3

  What is meant by a single-stage double-acting reciprocating compressor?      In a double-acting air compressor, the air is admitted alternatively to both sides of the piston. When one side is performing the suction stroke, the other side will be performing compression & delivery of compressed air. Theoretically, a double-acting compressor will deliver twice the amount of compressed air compared to a single-acting compressor of the same size and speed. Define volumetric efficiency and clearance ratio Volumetric efficiency: Volumetric efficiency is defined as the ratio of the volume of free air sucked into the compressor per cycle to the stroke volume of the cylinder. Clearance ratio: Clearance ratio is defined as the ratio of clearance volume of swept volume (or) stroke volume. What are the drawbacks of single-stage compression?      The size of the cylinder will be too large. Due to compression, there will be a rise in air temperature and it will be difficult to reject the heat i