Upload
vijayiocl
View
143
Download
12
Embed Size (px)
DESCRIPTION
Maintenance of reciprocating compessor, piston ring, rider ring, pressure packing, oil scrapper ring, intermediate packing
Citation preview
1
Maintenance of Reciprocating Compressor
.
2
- Components of Compressor -
PISTONPISTON ROD
CROSSHEAD
CONNECTING ROD
CRANKSHAFT
CYLINDERCROSSHEAD GUIDE FRAME
3
- Installation Flow -
Crankshaft
Main Bearings
Crosshead & Connecting Rod
Rod Packing
Piston
Compressor Valves
Coupling / Alignments
Bar-over Test
Ass
emb
le
Dis
asse
mb
le
4
- Location of Bearings -
CROSSHEAD PIN BEARING / BUSHCRANK PIN BEARING
CROSSHEAD SHOE
MAIN BEARING
5
- Disassembling of Main Bearings -
Disassemble frame tie rod
Remove the cap with upper metal
W ie r Rope
Se t Screw Lowe r Me ta l
Uppe r me ta l
Eye Bo l t
Install special tool into oil hole of crankshaft
Turn the crankshaft and remove the lower metal
To Tu rnD isa ssemb l ing Too l C rank Sha f t
Lowe r Me ta l
6
- Assembling of Main Bearings -
Assembling lower metal
Assembling crankshaft
Assembling upper metal with cap
Tighten the upper cap by torque wrench
(820 N-m)
7
- Construction of Crosshead & Connecting Rod -
8
9
- Assembling of Connecting Rod -
Assembling of connecting rod can be done by the opposite flow of assembling.
However, tightness of big end bolts are controlled by its elongation.
So, please measure its length before and after installation.
10
- Disassembling of Crosshead -
After disassembling of piston and connecting rod.
Tilt the crosshead by 90 ゚ and take out crosshead from window of crosshead guide or compressor frame.
11
- Assembling of Crosshead -
In case of assembling of crosshead, please take care that there are two type of crosshead shoes.
One is “C”shoe and the other is “O” shoe.
And after assembled to the crosshead guide, clearance between crosshead and crosshead guide to be recorded.
Planned clearance is 0.20 – 0.29mm and the using limit is 0.40mm.
O Shoe C Shoe
C Shoe O Shoe
Clearance
:Measu r ing Po in t
12
- Measurement of Crank Arm Deflection -
270 ゚
90 ゚
180 ゚
0 ゚1. Set the deflection gauge
(special dial gauge) between each crank arm at 0 ゚position.
2. Turn and measure the movement at 90 ゚ , 180 ゚ , 270 ゚ .
3. For example, if the measured deflection is 0 – +0.06mm, jack up the turning gear at the half of the measured value of 0.03mm.
4. Adjustment limit is 0.03mm and using limit is 0.06mm
13
- Construction of Cylinder -
PISTON ROD PACKING
DISCHARGE VALVE
SUCTION VALVE UNLOADER
CLEARANCE POCKET
SUCTION VALVECYLINDER LINER
PISTON
14
- Construction of Piston Rod Packing-
● Piston rod packing
Rod packing
Packing case
Tie bolt
Gater Spring
15
- Assembling of Piston Rod Packing -
FRAME S IDE
No .1&2R1 R0T1
R0R3 T5No .3&4
T5T5No .5
(a)
(b) (c)
There are three types of packing.
・ Butt-cut type (a)
・ Step-cut type (b)
・ Backup ring (c)
Please take special care for the direction & combination of packings.
Incorrect direction or combination will cause the leakage of gas.
After assembled to packing case, please measure the side clearance and record it.
16
- Construction of Piston -
● Piston ring
●Rider ring
● Piston rod ● Piston nut
17
- Assembling of Piston -
CHA IN BLOCK
P ISTON RODWRENCH
REMOVE THE NYLON SL ING
CYL INDER
ROD PACK ING PROTECTOR
AFTER INSERT ING ROD
WE IGHTLENGTH a
a
1ST A /B : 208 kg1ST A /B : 2145
Pro te c t ing Capfo r P i s ton Rod Pa ck ing
Assemble piston rod & piston rings to piston
Set piston rod wrench to piston nut & set protector for the
threaded portion of piston rod
Then, hoist the piston assembly and install into cylinder
Inserting the piston assembly, install the rider rings to piston
Screw in the piston rod to crosshead
18
- Assembling of Piston -
Adjust the screw travel by markings on piston rod and crosshead by using divider.
Then, tighten cross nut.
The reference length indicated on window of crosshead guide
Measure the clearances between piston & cylinder liner for four
directions
Assemble cylinder cover
Carry out bar-over test
(End clearance, runout)
19
- Assembling of Piston Rings -
(1) Two PPS ring form one set. In case of exchange exchange as set not one ring alone.
(2) At installation, install the piston rings in the direction parallel with piston axis. Don’t install from direction “b”.
(3) After assembled to piston, measure and record the side clearance.
(4) When assembling, locate the two rings 180 ゚ apart each other.
P i s ton R ing P i s ton Body
D i rec t ion "a "
D i rec t ion "b "
× ○
20
- Maintenance of Rings -
P is ton
P is ton R ing
In i t ia l Wea r L im i t
(1) Wear limit of piston rod packing is 3mm at the height of the ring. In case of replacement, do not replace one ring alone. The planed life of rod packing is 8000hrs, so maintenance required within 8000hrs.
(2) The planned life of piston ring is also 8000hrs however, only for initial operation, we recommend you to overhaul at 4000hrs to estimate the actual life.
21
- Maintenance of Rings -
Gap
0 .5mm
Wea r L im i t
×
×
×
×
×
Dimention
T ime
L i fe Expec ted Nex t Check
(1) The wear limit of rider ring is by the bottom clearance between piston and cylinder liner becomes 0.5mm. The planned life is 8000 hrs, however, for initial maintenance, we recommend you to carry out overhaul at 4000hrs to estimate the actual life.
(2) To determine the life, please plot the clearance versus operation time like the below graph.