compressor cylinder components a/b

Question 1

Rod reversal to the movement of the crosshead pin under alternating forces of compression and tension.

a) true
b) false

Answer 1

True

Question 2

Piston speed is constant while travelling from BDC and TDC.

a) true
b) false

Answer 2

False: It depends on the angle of crank throw

Question 3

Piston ring end gap is checked with the rings installed on the piston.

a) true
b) false

Answer 3

False: Piston ring end gap is checked with the rings installed in the cylinder without piston.

Question 4

On a large, two-stage, double-acting compressor, it is most likely that the first-stage piston is made of aluminum while the second-stage piston is made of cast iron to help to balance the reciprocating weight.

a) true
b) false

Answer 4

True

Question 5

Decreasing suction pressure results in __ compressor rod loading.

a) increasing
b) lowering

Answer 5

Increasing

Question 6

The proper way to set clearance between the piston and the cylinder head is to have 2/3 on the head end and 1/3 of the total clearance left on the crank end.

a) true
b) false

Answer 6

True

Question 7

What happens if the surface on the piston rod is scratched or damaged?

Answer 7

It could ruin the seal through the packing seal area or oil wiper area.

Question 8

What is the purpose of properly setting the piston to head clearances?

Answer 8

It prevents the piston from hitting the head during operation.

Question 9

Inlet cooling water temperature should be slightly warmer than the inlet gas temperature.

a) true
b) false

Answer 9

True

Question 10

When a cylinder is hydro-tested after an overhaul, the test pressure used is 1 1/2 times normal operating pressure.

a) true
b) false

Answer 10

True

Question 11

Name two (2) types of cylinders liners.

a) ____
b) ____

Answer 11

a) dry

b) wet

Question 12

We inspect (measure) cylinders to see if they are:

a) straight
b) round
c) within specified dimensions
d) all of above

Answer 12

d) all of above

Question 13

A honed surface on a cylinder surface promotes what two (2) things?

a) ______
b) ______

Answer 13

a) cylinder and ring lubrication

b) ring sealing and break-in

Question 14

The top of the cylinder is the best location for the cooling water inlet to keep the cylinder full of coolant.

a) true
b) false

Answer 14

False: The bottom is the best location for the cooling water inlet to prevent trapping air

Question 15

Clearance pockets are used primarily to control pressure.

a) true
b) false

Answer 15

False: Clearance pockets control output

Question 16

List the four (4) different ways that a compressor packing must be able to move in order to work effectively.

a) ____
b) ____
c) ____
d) ____

Answer 16

a) axially
b) rotate
c) laterally
d) expand/contract

Question 17

The markings on the oil wiper rings must face the cylinder side for proper installation.

a) true
b) false

Answer 17

False: The markings on the oil wiper rings must face the crank end

Question 18

What are balanced nuts used for?

Answer 18

Used to fin tune the weight balancing oppossing multi stage reciprocating compressors parts

Question 19

What is the rule of thumb for setting piston clarance when there is no manufacturers specificatione?

Answer 19

1/3 piston to crank end and 2/3 piston to head

Question 20

What ring do you use when piston rides over valve ports?

Answer 20

Uncut rider band

Question 21

What are 3 types of piston rings?

Answer 21

Butt joint, angle joint, step joint,

Butt joint is the most common used on compressor and oil control rings.

Step joint reduce leakage when a more sufficient seal is needed.

Question 22

What temp do you want the cooling water come in at and where does it enter at and leave at?

Answer 22

5 to 10°C higher Then the incoming gas. Water should enter from the bottom of the cylinder and exit at the top to ensure the water jacket is full of cooling water with out any air pockets.

Question 23

Using water that is too cold for compressor cooling can result in what?

Answer 23

Using water that is too cold for compressor cooling can result in condensation inside the cylinder which washes out lubrication and accelerates wear

Question 24

What are clearances pockets?

Answer 24

Used to control the output of a compressor while keeping up with the pressure they can be either fixed or variable control clearance pockets

Question 25

What. Does VVCP mean?

Answer 25

Variable volume clearance pocket

Question 26

When should you adjust a VVCP ?

Answer 26

When the machine is not running