OVERHAULING PROCEDURE OF CENTRIFUGAL COMPRESSOR AND RECIPROCATING COMPRESSOR

OVERHAULING PROCEDURE FOR BARREL TYPE COMPRESSOR:

• Proper safety clearance getting from concerned operation 

• remove coupling spacer from driver, turbine or motor. remove coupling by use of coupling puller like hydraulic puller or special tools.  

• before check the thrust clearance of the compressor shaft with thrust bearing.

• before you to do remove the head should be check that all oil lines are dismantled.

• remove cover and remove the instrument probe like thrust and radial probe with help of instrumentation.

• remove bearing housing cover and take care cover gasket for maintaining thrust clearance

• remove thrust bearing and thrust disc by removing of lock nut.

• remove split journal bearing two side and make mark, which side is coming 

• remove seals like floating seals with 3 rings. remove shear rings use of special tools an should be measure dimension where its locked and inspect the anti lock pin ok or not

• remove head locking shear ring and pull up the head by use of jack bolt and special puller use lifter to tight with head and transfer to the safer place.

• before removing the rotor, you should tight the diaphragm and rotor itself by use stud bolts for no need to remove one by one, pull out rotor with diaphragm to end position of barrel casing.

• use belly band like clamp for holding and transfer the rotor and diaphragm to where you need

• remove split diaphragm and clean well. check the rotor any damage and check the wear ring clearance, inner stage labyrinth clearance, rotor balancing and run out

• perfect inspection to be done on each and every part for any damage, score, marks, white metal pieces and tidy

• assembling is the reversal procedure for dismantling and the following factors should be considered  while before assembling rotor run out, balancing the rotor and check the inter stage labyrinth clearance, check the seals are properly seated, bearing clearance thrust an radial.

OVERHAULING PROCEDURE FOR HORIZONTALLY SPLIT TYPE COMPRESSOR:

• remove coupling guard and coupling to disconnect from driver. ensure auxiliary lines are disconnected from the compressor like suction and discharge lines, lines for lube oil, seal oil lines, buffer gas, etc.,

• remove bearing case of inboard with top split of compressor and remove end cover and out board bearing split case from the top split casing

• let the top casing free and remove casing bolts and pulled up top casing using jack bolts

• provide guide rods before lifting to avoid any impacts of parts and safe guarding labyrinth

• now we can check the all viewed parts of rotor, diaphragm visually for any damage 

• check free rotation, bearing radial and thrust clearance before dismantling and record readings 

• dismantle and remove seals of both side and after bearing retainer and top of bearing split housing of both sides

• takeout rotor from its position carefully

• remove bearing bottom housing and inspect each and every parts for any damage, score, rubbing, wear of labyrinths of al places, diaphragms, ports for seal oil, buffer gas

• recondition is better than change new one. keep always one rotor as standby to overhaul

• while assembling fixation of seal should be followed after the top case boxed up. use proper sealing compound in between joints of upper and lower casing.

• assembling is the reverse procedure of dismantling. the following factors should be while after assembling are, labyrinth clearances of all areas, ports free condition, proper seating of parts and o-rings, clearance between seal rings and bushing, bearing radial and thrust clearances, measurements with in design, free rotation, alignment and etc.,,

OVERHAULING PROCEDURE FOR RECIPROCATING COMPRESSOR

• Disconnect all auxiliary lines like discharge, air inlet, loader air, cooling lines

• Decouple coupling to disconnect with driver and remove crank case foundation bolts to transfer total unit to workshop for carrying overhaul.

• Remove the both suction valves with loader and discharge valve from head.

• open all inspection doors provided and loose the nut connects cross head and piston an takeout piston assembly with rod through head side. while removing care should be take about piston rings falling.

• dismantle piston plates, piston rings, expander rings, wear band and rod.

• Remove cylinder house with crank case with distance piece and disconnect distance piece dismantle wiper packings and gland. 

• Remove wrist pin and take out cross head

• Dismantle connecting rod big end and bearing cover and remove split big end bearing and take connecting rods outside

• Remove coupling hub and flywheel

• Remove lube oil pump connected with outboard of crank shaft and inboard cover

• Remove main bearings of connecting rod top half and take out crank shaft outside 

• Remove bottom half of main bearings

• Now complete dismantling is over. perfect inspection of each and every parts to be done while and after dismantling of any damage, score, break and etc.,

• Better is changing new one instead of reconditioning damaged parts

• assembly is the reverse procedure of dismantling.

• When assembling the following factors should be considered are main bearing radial and thrust clearances, connecting rod big end bearing and small end pin clearance, web deflection, rotor runout, wear band clearance, piston plate clearance with cylinder bore, bore surface finish, piston ring end and side clearance, piston end clearance,  oil tubes condition, valve lift an passing, loader piston freeness action, wiper packing clearance, free rotation and alignment. 

CHECKING THE CLEARANCE DURING OVERHAUL PROCEDURE:

• PISTON END CLERANCE

• PISTON RING SIDE CLEARANCE

• PISTON RING END CLEARANCE

• DIAMETRICAL CLEARANCE BETWEEN PISTON WITH CYLINDER / LINEAR, 

• RIDER RING DIAMETRICAL CLEARANCE

• WEB DEFLECTION 

• PISTON ROD RUNOUT

• CONNECTING ROD BIG & SMALL END BEARING CLEARANCE

• CRANK SHAFT MAIN BEARING CLEARANCE

• CRANK SHAFT THRUST ALLOWANCE

• CROSS HEAD WITH CROSS SIDE CLEARANCE

• GAS AND OIL WIPER PACK CLEARANCE