Reciporcating compressors

Question 1

reciprocating compressor oil sumps are usually painted with an oil resistance coating to

keep the oil contaminants out of the oil

prevent corrosion

trap any casting sand that might be left in the sump

both the 2nd and 3rd answer is correct

Answer 1

Both second and third answers are correct

Question 2

when designing a foundation, you must make sure that it

keeps the frame from distorting

allows proper alignment of the compressor to the driver

has sufficient mass and be isolated from rest of the building

all the above

Answer 2

All of the above

Question 3

when doing a wire alignment on a compressor, you need to know _______________ to accomadate for wire sag between the 2 end points of the wire

the size of the wire and the weight of the wire

the size of the wire and the amount of weght attached to the end of the wire

the size of the wire, the amount of weight attached and the distance between the 2 end points

the wire will not have sag in it

Answer 3

the size of the wire, the amount of weight attached and the distance between the 2 end points

Question 4

in a multi-stage compressor, to balance the inertial forces, pistons are

made of aluminium

heat treated

hollowed out

both the 1st and 3rd answer are correct

Answer 4

Both first and third answers are correct

Question 5

chroming is done to rods and journal surfaces to make them long wearing

true

false

Answer 5

True

Question 6

when balancing crankshafts you would_______________ to resolve reciprocating forces

use apposed throws and counter-weights

used apposed throws and add inertial forces

use counter weights traveling in the same direction as force

use counter-weights and add inertial forces

Answer 6

Use apposed throws and counter weights

Question 7

if you could put a 0.002 feeler gage under the shaft at one of the main bearings, when the shaft is sitting in the bottom of all the main bearings, what would happen if you ran it this way

nothing, it is ok to run it this way

the bearings beside it would fail more quickly

the crank would have more axial float

oil flow would be minimal thru this bearing

Answer 7

The bearing beside it would fail more quickly

Question 8

for every rvolution of the crankshaft you will have one suction stroke and one compression stroke. this would be a

double acting piston

single acting piston

Answer 8

Single acting piston

Question 9

piston rods

are used to join the piston to the crosshead

are chrome plated to increase their life

are screwed into and locked onto the crosshead with a nut

all the above

Answer 9

All of the above

Question 10

rod loading is when the rod

is under compression

is under tension

both the 1st and 2nd answers are correct

none of the above

Answer 10

Both first and second answers are correct

Question 11

rod reversal is

the reversal of the rod laod from compression to tension

good for lubrication

improved with a tail rod

all the above

Answer 11

All of the above

Question 12

excessive rod loading does ____________________ to happen

not allow misalignment

not allow corrosion

not allow full film lubrication

allows full film lubrication

Answer 12

Not allow full film lubrication

Question 13

in a double acting piston, when the piston is at TDC, the valves are_____________

open

closed

open and closed

none of the above

Answer 13

Closed

Question 14

no oil rings exist on double-acting compressors or non-lubricated compressors

true

False

Answer 14

True

Question 15

cast iron piston rings are used because

they are cheap

they are brittle

they conform quickly and are self-lubricating

both the 1st and 3rd answers are correct

Answer 15

First and Third answers are correct

Question 16

oil control rings control the flow of oil on cylinder walls by

allowing oil to flow onto the wall on the up-stroke thru holes in the ring

scraping oil off the cylinder walls with the oil ring

not having an expasion ring

both the 1st and 2nd answer are correct

Answer 16

Both first and second answers are correct

Question 17

installation of piston rings should have the gap staggered _______ degrees when the piston has 2 pressure rings

90

45

180

360

Answer 17

180 degrees

Question 18

synthetic rings out last metallic rings in enviroments such as

abrasion

acidic gasses

corrosion

all the above

Answer 18

All of the above

Question 19

you would check for piston ring end gap when the ring is

on the psiton and the piston is in the cylinder

in the cylinder at the smallest diameter

on the piston in the piston groove

on the bench without being installed on anything

Answer 19

In the cylinder at the smallest diameter

Question 20

piston rider bands

prevent the piston from touching cylinder during startup and operation

support 100% of the piston weight and 100% of the piston rod weght

have a tongue and groove cut ring

all the above

Answer 20

Prevents the piston from touching the cylinder during start up and operation

Question 21

uncut rider bands are machined with a interference fit. when stretched on and into their grooves, they will

shrink to a snug fit in the groove

stay loose in the groove

need a backup ring to support it

both the 2nd and 3rd answers are correct

Answer 21

shrink to a snug fit in the groove

Question 22

a special clamping device and torque multiplier will be needed to install the ___________ into the ______________

rod, crosshead

rod, piston

crosshead, crankshaft

crankshaft, rod

Answer 22

Rod, Piston

Question 23

the piston rod is screwed into the crosshead and locked in place with

lock nuts

balancing nuts

set screws and lock wire with the lock nut

all the above

Answer 23

All of the above

Question 24

when removing the piston and rod from the crosshead and out of the cylinder, you will

need to record the number of turns to remove the rod from the crosshead

rotate the driver to move the crosshead out of the way

carefully pull piston and rod out thru the cylinder without scoring it

all the above

Answer 24

all of the above

Question 25

if setting the piston clearances, when the compressor is cold, you will set the crank head clearance at 2/3 and the head end clearance to 1/3 of the total clearance set the crank head clearance to 1/3 and the head end clearance to 2/3 of the total clearance set both head end and crank head clearance to 50% make sure there is no contact at either end

Answer 25

Set the crank head clearance at 1/3 and the head end clearance to 2/3 of the total clearance

Question 26

_________________ are used to fine tune the weight balancing of opposing multi-stage reciprocating compressor parts balancing nuts lock nuts set screws lock wires

Answer 26

Balancing nuts `

Question 27

clearance pockets can be fixed or variable and they help match the output of the compressor to the demand of the system can be a plug or bottle type can be VVCP all the above

Answer 27

all of the above

Question 28

when reversing a clearance plug, the compressor capacity will be increased reduced stay the same none of the above

Answer 28

Reduced

Question 29

you can only adjust the VVCP when the compressor is running true false

Answer 29

False when not running

Question 30

hydro-testing a cylinder, you would pressurize the cylinder to 1.5 times the max working pressure true false

Answer 30

True

Question 31

when you have a large industrial compressor with a cylinder of 3 meters extending from the main frame, you will need to support it so the frame and distance piece do not take all the load or weight. the support is pre-loaded to take some of the weght true false

Answer 31

True

Question 32

what is the shim move needed if R = 0.01, L = 36", S = 6" R/S=X/L X= shim move 0.050 0.060" 0.075" 00.80"

Answer 32

0.060

Question 33

the packing prevents excessive leakage of compressed gas along the piston rod and into the distance piece true false

Answer 33

True

Question 34

free floating mechanical packing moves in all directions has cups has segmental sealing rings all the above

Answer 34

All of the above

Question 35

which of the following is NOT a type of packing ring pressure breaker radial cut tangential cut cup cut

Answer 35

Cup cut

Question 36

the pressure breaker ring is located in the middle of the packing closest to the frame closest to the cylinder does not matter

Answer 36

Closest to the cylinder

Question 37

on low pressure single sealing (one-direction) the radial ring is doweled to the tangent ring. the radial ring must be installed on the pressure side with the markings (dots) on both rings facing the pressure side true false

Answer 37

True

Question 38

the double acting ring combination, seals in both directions true false

Answer 38

True

Question 39

packing case design is dictated by type of application, pressure and compressor speed, this will determine the # of cups and rings if cooling is needed if lubrication is needed all the above

Answer 39

All of the above

Question 40

cup joints can be lapped with an O-ring, gasket joint or tongue and groove which helps seal between the cup faces true false

Answer 40

True

Question 41

when using lubricated and vented packing, the vent is located on the top bottom

Answer 41

Bottom

Question 42

the oil wiper ring is located next to the cylinder in the distance piece middle of the distance piece crank side of the distance piece anywhere in the distance piece

Answer 42

Crank side of the distance piece

Question 43

in operation, the 1st oil wiper ring turns back most of the oil to the crankcase and the rest is scraped off by the internal scraping of the ring true false

Answer 43

True

Question 44

the distance piece is used to prevent cylinder leakage from pressurizing the main frame prevent oil from the crankcase getting into the cylinder access the packing, wipers and checking rod runout all the above

Answer 44

All of the above

Question 45

you could use a 2 compartment distance piece to totally seal off an explosive gas coming form the compressor chamber true false

Answer 45

True

Question 46

the purpose of the crosshead is to centre the piston rod in the packing case true false

Answer 46

True

Question 47

adjustable crossheads with removable shoes can use shims at the bolt locations to alter the clearance between the crosshead and guides

Answer 47

True

Question 48

the rod nut face must be smooth and free of burrs and dirt. the mating face of the lock nut should be perpendicular to the rod nut face true False

Answer 48

False must be parallel

Question 49

the lock nut is used to adjust the position of the piston by allowing the piston rod to turn into and out of the crosshead true False

Answer 49

True

Question 50

the connecting rod has a bias cut when you have to pull the the connecting rod thru the cylinder bore true False

Answer 50

True

Question 51

you need dowel pins on both sides of the parting line of the rod cap to hold the 2 halves in proper alignment true False

Answer 51

True

Question 52

when taking the connecting rod out, make sure to match mark the 2 pieces true false

Answer 52

True

Question 53

if plasitigage is not reading the proper clearance, you would look at __________ as the cause dirt under the bearing insert wrong size of bearing insert beraring insert caught on tag or tap all the above

Answer 53

All of the above

Question 54

when using locking plates to retain the crosshead pin, the device requires connecting rod and crosshead to be separated before pulling the unit true false

Answer 54

False Cannot remove beforehand?????

Question 55

with single a single acting compressor, you must remove the connecting rod thru the cylinder true

Answer 55

True

Question 56

oil starvation to the bearings causes the bearing surfaces to over heat wipe away have their clearances decrease both the 1st and 2nd answers are correct

Answer 56

Both the first and second answers are correct

Question 57

measurments taken between the crosshead and guides should measure between ____________" 0.12 to 0.15 0.17 to 0.20 0.007 to 0.010 0.001 to 0.002

Answer 57

.007 to .010

Question 58

to check for rod runout, you would put the dial indictor on top of the rod in the distance piece and cycle the crankshaft form BDC to TDC true false

Answer 58

True

Question 59

the largest factor effecting a compressors efficiency is piston and ring wear leaky packing improper valve operation the clearance volume

Answer 59

Improper valve operation

Question 60

the 4 components of compressor valves are sealing element, valve seat, assembly elements and valve gaurd true false

Answer 60

True

Question 61

when using v-shape rings and flat rings for cylinder head valves, which one has a smoother flow path and less chance of deposits forming v-shape flat no difference

Answer 61

V-Shaped

Question 62

for the size of the valve, which valve allows for the least restriction to flow, since there are no flow reducing webs ring plate

Answer 62

Ring

Question 63

dampen disc valves are used to reduce compressor valve flutter true false

Answer 63

True

Question 64

alve flutter is a condition where the sealing element rebounds off the piston true false

Answer 64

False Look up right answer

Question 65

feather valves do not use pressure differential to move the strip suction springs all the above

Answer 65

Springs

Question 66

bringing cooling water temperatures to above incoming gas temperatures will prevent slugs cause condensation in the cylinders cause coking all the above

Answer 66

Prevent plugs

Question 67

coking is caused by too much water on a hot discharge valve too much oil on a hot discharge valve lack of heat of compression valve flutter

Answer 67

to much oil on hot discharge valve

Question 68

too little lift in a sealing element will cause ____________________ which causes lower compressor capacity an increase in both horsepower and gas temperature increased valve wear leaky valves an increase in compressor capacity

Answer 68

An increase in both horsepower and gas temperature

Question 69

to test compressor valves and their seats for leakage, you would ___________________ and tap the valve plate and seat to clean the seal area after a slight pressure build up during the test use a pressure drop test use a flow meter test use a HP test both the 1st and 2nd answer are correct

Answer 69

Both first and second answers are correct

Question 70

when removing valves from a reciprocating compressor, you should make sure to vent the cylinder by backing off the valve cover nuts a few turns and tapping the cover to jar it loose from its seat true false

Answer 70

True

Question 71

valve covers should have some clearance between them and the cylinder housing after the bolts are torqued true false

Answer 71

True

Question 72

there is very little physicl difference between suction and discharge valves except the direction they are orientated. you can check for orientation by pushing on the sealing element. a discharge valve will open _____________________ away from the nut towards the nut

Answer 72

Towards the nut

Question 73

in oil systems, the most important aspect of oil in a compressor system is the oils viscosity true false

Answer 73

True

Question 74

the best oil system for double acting compressors is splash gravity splash and gravity full pressure

Answer 74

Full pressure

Question 75

pressure in a positive displacement pump system is created by the pump maximum pressure relief valve bearing clearances none of the above

Answer 75

Bearing clearances

Question 76

the maximum pressure relief valve is there to protect the compressor oil system from excessive lube pressure true False

Answer 76

True

Question 77

filter systems for the lube system are usually partial flow full flow mixed flow unfiltered

Answer 77

Full flow

Question 78

metered oil is used in the packing cases main frame cylinders both the 1st and 3rd answers are correct

Answer 78

Both first and third answers are correct

Question 79

divider valves ae used to supply metered oil to many points with 1 pump true false

Answer 79

True

Question 80

the divider block lubrication system cannot tolerate dirt, air, gas or leaks. it must b full of oil and free of air to work properly true false

Answer 80

True

Question 81

you would use a venture silencer with paper filter elements with a screw compresor vane compressor reciprocating compressor none of the above

Answer 81

Reciprocating compressor

Question 82

the filter that spins the dirty incoming air to help separate the dirt from the air is the fabric oil-wetted labyrinth scrubber inertial

Answer 82

Inertial

Question 83

when cylinder cooling, the coolant should start near the discharge vlaves and exit near the suction valves true false

Answer 83

True

Question 84

piston rod run out would have a proximity sensor that would measure rod drop true False

Answer 84

True

Question 85

by opening a clearance pocket to a larger size in a compressor, you would increase its capacity decrease its capacity increase valve lift decrease valve lift

Answer 85

Decrease its capacity

Question 86

valve designs for high speed compresors will have high lift valves wide ports low lift valves no ports

Answer 86

Low lift valves

Question 87

the minimum, H2S gas amount that could kill you within 8 to 48 hrs is 0.010 % 0.050 % 00.40 % 0.030 %

Answer 87

0.010

Question 88

filling out permits will alert you to potential dangers that may be overlooked and ensures you will follow established safety routines. you will also meet with everyone involved to review the safety procedures true false

Answer 88

True

Question 89

following manufactures specifications will help you with understanding the procedures involved true False

Answer 89

True

Question 90

OEM is the best place to find someone with equipment knowledge and system knowledge of their equipment true false

Answer 90

True

Question 91

organizing parts and labeling of the parts will help your team (when different people will be working on the same equipment at different times or shifts) true false

Answer 91

True

Question 92

rotating crankshafts when compressors are in storage, would help stop brinelling false brinelling spalling flaking

Answer 92

False brinelling

Question 93

before starting up a large compressor, you should make sure to __________ after an overhaul or on a first start up prelube the bearings check rotation of prime mover and compressor bar compressor over a full 360 degrees all the above

Answer 93

all of the above

Question 94

when starting a compressor, you must shut down the compressor immediately (within 5 seconds of not having oil pressure)--- normally about 45 psi true False

Answer 94

True

Question 95

rapidly wearing packing could be caused by an incompatible gas being compressed true False

Answer 95

True

Question 96

when doing a flush of the lubrication system in a reciprocating compressor system, it is necessary to bar over the compressor a 1/4 of a rotation every 15 to 20 minutes during this flush true false

Answer 96

True

Question 97

a tail rod is used to equalize the surface area which reduces tha capacity of the compressor but ensures rod reversal true false

Answer 97

True

Question 98

failure analysis collects and analyzes data to find out the causes of a failure. operator logs are an excellent source of info for analysis true False

Answer 98

True

Question 99

changes in oil sample readings can help detect wear rates of bearings the oils viscosity and additive levels the filters efficiency level all the above

Answer 99

All of the above

Question 100

why should you check for proper rotation if a 3 phase motor drives the compressor and it was replaced compressor is driven in the proper direction lube pump driven in proper direction the wires could be reversed all the above

Answer 100

All of the above

Question 101

labyrinth compressors use ___________to help control pressure drop across the cylinder wall and piston piston rings oil rings grooves on the cylinder and piston all the above

Answer 101

Grooves on the cylinder and pistons

Question 102

diaphragm compressors are used where _______________is needed pulsation free air is needed oil free air is needed leakage is acceptable all the above

Answer 102

Oil free air is needed

Question 103

intercoolers are used to cool the compressed air between stages decrease the amount of power required to compress the gas remove moisture from the air all the above

Answer 103

All of the above

Question 104

displacement is the total volume of air moved out of the compressor cylinder the total volume of air the compressor compresses divided by the compression ratio the total volume of air moved out of the compressor cylinder in a given unit of time total volume of air the compressor takes in divided by the compression ratio in a given unit of time

Answer 104

the total volume of air moved out of the compressor cylinder in a given unit of time

Question 105

swept volume is equal to the area of the piston area times the length of stroke does not include the clearance volume includes venting both the first and second answers are correct

Answer 105

Both first and second answers are correct

Question 106

the difference between venting and purging is venting is pressure release while purging is cleaning the system with inert gas venting is cleaning the system with inert gas while purging is pressure release they both mean the same thing all the above

Answer 106

venting is pressure release while purging is cleaning the system with inert gas