ESP Manual: Ash Removal and Electrostatic Precipitators Maintenance

1. General

1.1 Purpose
The purpose of this manual is to enhance the management of the maintenance process for the
equipment involved in the ash removal handling system. It aims to normalize maintenance
procedures and establish guidelines for the maintenance of equipment within the ash removal
handling system.

1.2 Scope
This document outlines the maintenance protocols for:
● Pneumatic ash removal handling system
● Compressed air system
● Limestone secondary conveyor system
● Bed material system

1.3 Abbreviations

Abbreviation Meaning

ASH HOP Ash Hopper

AUTO Automatic

BEAR Bearing

BELT Belt
BIN Bin

BFV Butterfly Valve

CHK V Check Valve

CPRESS AIR Compressed Air

CTNR Container

FLAN Flange

HDR Header

HTR Header

IND WTR Industrial Water

LUB OIL Lubricant Oil

PIP Pipe
PNMTC Pneumatic

PREC Precipitator

PRESS, P Pressure

PULSE Pulse

PMP, P Pump

RTN (OIL, WTR) Return (Oil, Water)

SEPTR Separator

SLAG REMOVER Slag Remover

SPR Spray

STM SRC Steam Source

STOREH Store House

SYS System

SWTH Switch

TEMP, T Temperature

TRANS Transportation

TRNG Turning Gear

Valve
VLV, V

3. References
● Air Compressor and Post Processing Equipment Technical Agreement
● Pneumatic Conveyor System Technical Agreement
● Ash Silo Equipment Technical Agreement
● Blower and Electric Heater Equipment Technical Agreement
● ESP Technical Agreement
 ● Impulse Bag Filter Technical Agreement
● General Design Description
● P&ID of Fly Ash System
● P&ID of Bottom Ash System
● P&ID of Limestone Handling System
● P&ID of Bed Material System
● P&ID of Air Compressed System
● Ash Silo Equipment Factory Data
● Shanxi Junma Pakistan Thar Project Limestone Powder Secondary Conveyor System
Data
● Gasification Blower and Electric Heater Factory Data
● Qingdao Songling Bucket Elevator and Bed Material Silo Factory Data
● Qingdao Songlin Chain Bucket, Bucket Elevator, and Slug Silo Factory Data
● Maintenance and Operation Manual for Dense Phase Pneumatic Handling System
● Thar Project As-Built Documents

4. Equipment Maintenance Project Summary

4.1 Removal of Ash Transfer Vessel and Ash Conveyance Pipeline Maintenance Project
1. Transfer Vessel Transmitter Inspection and Maintenance
2. Manual Inspection Door Inspection or Replacement
3. Expansion Joint Inspection or Replacement
4. Radius Inspection or Welding Repair
5. Intake Valve Inspection or Replacement
6. Ash Pipeline Inspection, Welding Repair or Replacement
7. Economizer Feed Valve Check or Replacement
8. Intake Valve Check or Replacement
9. Check Valve Replacement or Repair
10. Blower Check or Replacement
11. Manual Thin Gate Valve Inspection or Replacement
12. Inspection of Air Ducts or Replacement

4.2 Maintenance Items of Ash Silo Equipment

1. Ash Silo Inspection
2. Staircase Inspection and Weld Repair
3. Inspection of Bottom Pneumatic Chute Pneumatic Plate Welding
4. Seal Plate Inspection and Replacement
5. Check Valve Replacement at Warehouse Top
6. Bag Filter Bag Inspection and Replacement
 7. Check and Repair or Replace:
● Air Bag
● Drain Valve
● Impulse Control Device
● Electromagnetic Pulse Valve
● Air-Water Separator
● Aluminum Alloy Venturi
● Galvanized Keel
● Vacuum Pressure Release Valve
● Exhaust Fan Combination of Bag Filter

4.3 Vaporizer Fan Maintenance Project

Maintenance Tasks
1. V-Belt Inspection and Replacement
2. Mouth Muffler Filter Check and Replacement
3. Exhaust Muffler Inspection and Replacement
4. Elastic Connector Inspection and Replacement
5. Safety Valve Inspection and Replacement
6. Thermal Resistance Inspection and Replacement
7. Check Valve Inspection and Replacement
8. Roots Pump Inspection or Disassembly Maintenance
9. Check and Replace:
● Cylinder
● Cover
● Flange
● Cyclone of the Ash Storage Tank
10. Check and Replace:
● Ash Bucket Heater Body
● Cover Plate
● Flange
● Cyclone Baffle

4.4 Overhaul of Automotive Bulkheads

Maintenance Tasks
 1. Inspection of the Bottom Retractable Discharge Cover
2. Inspection and Maintenance of Bulk Elevator Lifting Mechanism, Wire Rope
Replacement
3. Outlet and Inlet Connector Inspection
4. Decelerator Repair and Maintenance

4.5 Double Shaft Mixer Maintenance Project

Maintenance Tasks
1. Dual Shaft Mixer Body Inspection and Weld Repair
2. Outlet and Inlet Connector Inspection
3. Water Spray Device Inspection and Replacement
4. Blade Inspection and Replacement
5. Inspection and Maintenance of the Electric Air Lock Body
6. Checking or Disassembling the Reducer
7. Drive Inspection
8. Feed Valve Check or Replacement
9. Gray-Conditioning Wet Pump Inspection or Disassembly Maintenance
10. Inspection or Disassembly of the Sewage Pump
11. Inspection Platform Inspection and Maintenance

4.6 Steel Supports, Stairs, and Platform Maintenance Items

Maintenance Tasks
1. Steel Bracket Inspection and Weld Repair
2. Stairs and Platforms for Inspection of Welding and Corrosion Protection

4.7 Ash Air Compressor Maintenance Project

Maintenance Tasks
1. Inspection or Disassembly of Compressor Body (Bearing Inlet)
2. Transmission Inspection and Maintenance
3. Air Filter Inspection: Clean or Replace the Filter
4. Exhaust Check Valve Inspection or Replacement
5. Oil and Gas Separator Inspection and Maintenance
6. Pressure Maintenance Valve Inspection or Replacement
7. Drain (Sewage) Valve Check or Replacement
8. Oil Cooler Inspection and Maintenance
 9. Oil Filter Inspection
10. Safety Valve Inspection or Replacement
11. Three-Way Solenoid Valve Inspection or Replacement
12. Air Outlet Check Valve Check or Replacement
13. Oil Level Lens Cleaning or Replacement
14. Intake Regulator Check or Replace
15. Filter Oil or Replace Grease

4.8 Dryer Inspection Items

Maintenance Tasks
1. Inspection and Maintenance of Cold and Dry Machine
2. Degreasing Filter Cleaning or Replacement
3. Dust Filter Cleaning or Replacement
4. Expansion Valve Inspection or Replacement
5. Check of the Gas Tank Body
6. Air Tank Automatic Drain Valve, Automatic Drain Valve Front Cast Steel Valve, Full-
Open Safety Valve Check or Replace

4.9 Safety Precautions

General Guidelines
1. Work Permit Formalities:
● Before commencing any inspection or repair work, ensure that all work permit
formalities are completed. This includes confirming that various safety measures
have been correctly implemented and that the work permit is signed.
● Safety measures, potential hazards, and control measures must be clearly
explained to all staff before maintenance work begins.
2. Personal Protective Equipment (PPE):
● Staff must adhere to safety regulations regarding attire. The following are
prohibited on the job site:Shorts
3. Tool and Equipment Safety:
● Workers must use only qualified tools and equipment for maintenance tasks.
● Damaged or incomplete tools must not be used to prevent unnecessary personal
injury.
4. Handling Spare Parts:
● During inspection and repair work, ensure that all spare parts and materials being
carried or moved are safe and reliable.
● Unauthorized movement of parts or articles is strictly prohibited.
 5. Post-Overhaul Safety:
● After completing overhaul work, ensure that no hidden hazards remain on the job
site. All areas should be left clean and safe.
6. Equipment Commissioning:
● For equipment commissioning, retain the work permit at the work permitter's
office.
● Upon successful trial operation, confirm that the work is complete.
● If further maintenance is required, all safety measures must be restored and
confirmed as correctly implemented (or a new work permit must be applied for)
before proceeding with additional maintenance tasks.

Chapter I: Maintenance Manual of Ash Removal Air Compressor

1. Overview
The air supply center is strategically located next to the Electrostatic Precipitator (ESP). The
system comprises six water-cooled screw-type air compressors, with four units operational and
two units on standby. An additional installation location for an air compressor has been reserved.

Specifications:
● Type of Air Compressor: M315-W8-2S
● Parameters:
● Capacity (Q): 62.1 Nm³/min
● Pressure (P): 0.85 MPa
● Power (N): 315 kW
●
In addition to the compressors, six sets of post-processing equipment are included, which consist
of combined-type air dryers, oil filters, and dust filters. Similar to the compressors, four sets are
operational while two sets serve as backups.

Post-Processing Equipment Parameters:

● Capacity (Q): 70 Nm³/min
● Pressure (P): 0.85 MPa

1.1 Applicable Conditions of Air Compressor

Overview
The air supply system includes six water-cooled screw-type air compressors, comprising four
operational units and two standby units. These compressors are designed to perform normal and
long-term safe operations under specific environmental conditions.

Operating Conditions
● Maximum Temperature: The compressors can operate safely at a maximum temperature
of 50°C.
● Relative Humidity: They are capable of functioning in environments with a relative
humidity of 71% or more.

Performance Specifications
● The oil-ejected screw-type air compressors are engineered for low vibration, low noise,
and high efficiency.
● The compressors, along with auxiliary equipment, are installed on a chassis to form a
complete box-type unit that integrates power and control systems.

Cooling and Air Inlet Conditions

● When the inlet cooling water temperature at the rear cooler is 38°C, the air inlet
temperature of the compressor must not exceed 15°C.
● The discharge pressure should be no less than 0.75 MPa, with an output capacity of at
least 50 Nm³/min.

Separator Requirements
● The air-oil separator must ensure that the air content (including oil droplets, suspended
particles, and oil vapors) at the outlet is controlled below 5 ppm.
● The size of oil particles should be limited to below 1 μm.
● The dew point of the air at the outlet under discharge pressure must not exceed 2°C.

Inlet Air Filtration

● Each air compressor inlet is equipped with a high-efficiency air filter or a combined
silencer filter.
● The maximum airflow rate through the filter should not exceed 1.0 to 1.3 m/s, with an
acceptable pressure loss ranging from 10 to 25 mmH₂O.

Additional Operating Parameters

 ● The compressors should operate normally in ambient temperatures not exceeding 55°C,
with cooling water inlet temperatures capped at 40°C.
● The return temperature of the compressor lubricant must not exceed 70°C.

Compression Mechanism
The core component of the screw air compressor is its main unit, which functions as an air
volume displacement compressor.
● Compression Process:
● Air compression is achieved through changes in volume created by the
engagement of male and female rotors within a precisely fitting housing.
● As the rotors rotate, they periodically change the volume of air between their
slots, pushing it along the axis from the suction side to the discharge side. This
process completes three stages: suction, compression, and exhaust.
●
The technology used in manufacturing twin-screw rotors determines the performance level and
positioning of the screw air compressor in its product category. This structured format enhances
clarity and readability while ensuring that all critical information is presented effectively

Air Compression Process

The air compressor operates through a systematic process to compress atmospheric air into a
usable form. The working principle can be broken down into the following stages:
1. Air Intake:
● Air enters the compressor through an intake filter, where it is filtered to remove
dust and other contaminants.
2.
3. Single-Stage Compression:
● The air is drawn into the single-stage compression chamber, where it is
compressed to an interstage pressure.
● As the air flows towards the second-level device, it passes through a cooling oil
curtain, which significantly reduces the intake temperature of the compressed air
by fully contacting the cooling oil.
4.
5. Second-Level Compression:
● In this stage, the air is further compressed to achieve its final exhaust pressure.
● The compressed air is then expelled from the second-level machine through an
exhaust flange and directed into a separator.
6.
7. Separation of Oil and Air:
 ● In the separator, cooling oil is removed from the compressed air.
● The cooling water, after performing its function, returns to the compressor inlet
for reuse.
● The air then enters a rear cooler from the separator, where it is cooled down to its
final exhaust temperature.
8.
9. Condensate Management:
● A water separator is employed to remove condensate from the compressed air,
which is drained out via a bleed valve.
● High-quality air is finally exhausted from the unit at the appropriate exhaust
pressure.
10.

Cooling System
● The cooling system consists of an oil bath, cooler, temperature control valve, and filter.
● During operation, cooling oil is pressurized and circulated to all bearings within the
compressor to maintain optimal operating temperatures.

Control Systems
● The machine features an "On-off line" loading control system that maintains a set exhaust
pipeline pressure during operation.
● An automatic restarting system is included for applications where air consumption
fluctuates significantly.

Instrumentation and Safety Features

● The instrument panel displays all working conditions and overall status of the air
compressor.
● When switching between On-off line and modulation modes in response to changes in air
consumption, the modulation system can expand to include modulation and auto control
models.
● Electrical components are housed within a metal plate electrical control cabinet for easy
maintenance.
● Safety mechanisms are in place to automatically stop the compressor in case of excessive
temperature, electrical overloads, or high system pressure.

1.2.2 Structural Features

1. Design and Configuration

 1. Air Inlet and Outlet:
● The air inlet is located at the upper end of the casing, while the air outlet is
situated at the lower part.
● Inside the casing, two high-precision rotors (main and auxiliary) are mounted
horizontally and parallel to each other.
2.
3. Rotor Specifications:
● The main rotor features five teeth, whereas the auxiliary rotor has six teeth.
● The diameter of the main rotor is larger than that of the secondary rotor, with a
spiral tooth shape rounding the outer edge of each rotor.
● The meshing of the two rotors is supported by bearings:Cylindrical roller bearings
4.
5. Transmission Mechanism:
● The compressor utilizes a direct transmission mode.
● A coupler connects the motor to the main unit, and a set of high-precision speed-
increasing gears is employed to enhance the rotating speed of the main rotor.
6.

2. Compressor Type
● The screw-type air compressor is classified as a single-stage double-screw oil injection
compressor.
● It employs a high-efficiency belt (or shaft) transmission to drive the main unit for air
compression.
● The compression chamber is cooled and lubricated through oil injection.

3. Separation Process
● After compression, exhaust air and oil mixtures are separated using coarse and fine
separation methods.
● The oil in the compressed air is effectively removed, resulting in clean compressed air.

4. Advantages of Twin-Screw Compressors

● Twin-screw air compressors are recognized for their excellent reliability and offer several
advantages:
● Light Weight: Facilitates easier installation and mobility.
● Low Vibration: Enhances operational stability and reduces wear on components.
● Low Noise: Operates quietly, making it suitable for noise-sensitive environments.
● Ease of Operation: Simple controls make it user-friendly.
● Fewer Vulnerable Parts: Reduces maintenance needs and enhances durability.
● High Operating Efficiency: Provides effective performance with lower energy
consumption.

Structure of screw air compressor shown in Figure:

-
2. Equipment Main Technical Data

M315WCλΔ LV

Parameter Value

Pressure 7 bar (L) 8 bar (M) 10.0 bar (H) 12.5 bar (XV)

Air Volume 65.0 m³/min 62.1 m³/min 56.2 m³/min 50.6 m³/min

Full-load Current (MAX) at

695 Amps
400V

Weight O.D.P 7350 kg

M315WCλΔ HV

Parameter Value

Pressure 7 bar (L) 8 bar (M) 10.0 bar (H) 12.5 bar (XV)

Air Volume 65.0 m³/min 62.1 m³/min 56.2 m³/min 50.6 m³/min
 Full-load Current of Fan (MAX)

At 380V 2.6 Amps

At 415V 2.5 Amps

Starting Current of Fan (MAX)

At 380V 18.2 Amps

At 415V 46.4 Amps

Full-load Current – Main

46.4 Amps
Motor at 6000V

Weight O.D.P 7550 kg

3. Operation of Air Compressor System

3.1 Inspection Before the Startup of Air Compressor

Before starting the air compressor, the following inspections should be conducted to ensure safe
and efficient operation:
1. Cooling Water Pipeline System:
 ● Ensure that the cooling water pipeline system has been washed and accepted as
conforming to standards.
2. Control Power Confirmation:
● Confirm that the control power of the air compressor is off (indicated by the
control power box light being off and no display on the air compressor control
panel).
● Open the shell door of the air compressor to check for debris on the floor and
equipment inside.
● Verify that power supply wiring and measuring points are securely connected.
● Ensure that the inlet air filter is clean and free of debris, and that the ventilation
fan and vent are unobstructed.
3. Visual Inspection:
● Check that the appearances of both the air compressor and air reservoir are intact
and complete.
4. Cooling Water Valves:
● Verify that the inlet and outlet doors for cooling water in the air compressor are
open, while ensuring that the water discharge doors of the inlet and outlet pipes
are closed.
● Confirm that cooling water pressure is within normal limits.
5. Oil-Gas Separator Check:
● Ensure that the water discharge valve at the bottom of the oil-gas separator is
closed, with no oil leakage present.
● Check that oil levels in both the oil-gas separator and tank are above the minimum
level.
6. Electrical Safety Checks:
● Inspect the in-situ electrical accident button to ensure it is intact and undamaged,
with the emergency stop button in the pop-up position.
7. Foundation Security:
● Confirm that foundation bolts are secure, complete, and not loose.
● Ensure that protective covers are intact and all connections are firm.
8. Control Panel Settings:
● Check that the small shift switch on the control panel is set to the non-load
position (“non-load/normal”).
9. Power Supply Connection:
● After completing all checks, contact for power supply from 11KV and ensure
connection to the control panel for the air compressor.
10. Electrical and Valve Functionality:
● Verify that all electrical and thermotechnical wiring for valves in the air
compressor system can be operated remotely.
 ● Ensure that opening and closing actions of valves are flexible and reliable, with
remote states consistent with in-situ states.
11. Valve Inspection:
● Conduct an inspection and interlocking test of valves within the air compressor
system.
12. Shut-Off Valve Status:
● Open the shut-off valve between the screw compressor, tank, and pipeline.
13. Panel Alignment:
● Before commissioning, re-align both the control panel and machine door.
14. Setting Value Check:
● Review setting values and make adjustments as necessary.
15. Bleed Screw Operation:
● Open the bleed screw of the rear cooler to exhaust any trapped air from it.

This structured format organizes all inspection steps clearly, making it easy for operators to
follow during pre-startup checks of the air compressor system.

3.2 Air compressor startup

1Air Compressor Operational Features

1. Start
● Functionality: The air compressor can be started when the main image is activated.
 ● Remote Control: The remote control mode will be reactivated.
● Fault Reset: The fault reset can be used as the confirmation key.

2. Manual Unloading
● Condition: Under a loading state, the machine can be uninstalled.
● Operation: The unloading key will be deactivated if it is not pressed.

3. Manual Loading
● Condition: In the unloading state, press the loading key.
● Operation: The machine will load until the pressure reaches the set threshold for
unloading.

4. Stop
● Functionality: Any interface can be pressed to stop the machine.
● Delay Mechanism: The stop command does not execute immediately; there is a delay
until the stop process is completed.

5. Liquid Crystal Interface Function Key

● Operation: Perform corresponding operations based on the displayed interface.

6. Liquid Crystal Interface Direction Key

● Functionality: Used for navigating up and down through pages and modifying parameter
values.

7. Power Indicator
● Status: The controller indicator is always illuminated, indicating power is on.

8. Running Light
● Status: The running light indicates that the air compressor is operational and running
continuously.

9. Alarm Indicator Lamp

● Warning Status:
● Flashing light indicates a warning condition for the air compressor.
● A solid light indicates a serious failure.
●
10. Communication Indicator Lamp
● Status: The communication indicator is continuously illuminated, indicating active
remote communication.

4. Air Compressor Operational Guidelines

1. Load Operation
● Functionality:
● The inlet valve opens.
● Air is inhaled into the compressor, raising the pressure.
● Compressed air is discharged to the back line.

2. Unloading Operation
● Functionality:
● The inlet valve closes (with a small amount of slot admission).
● The compressor operates with very low compressed air.
● Air is returned to the inlet via the air valve, and the unit does not discharge from
the pipe.

3. Oil Level Observation

● Guidelines:
● During loading, observe the oil level in the cylinder.
● The oil level should be in the middle green area; higher levels are not necessarily
better.
● Do not check the oil position when unloading or stopping.

4. Safety Measures
● Emergency Stop:
● If there is a risk to personnel or equipment, pressing the stop button will not halt
operations immediately (there is a delay).
● For an immediate stop, use the controller located next to the button; this is not
considered an emergency stop.

5. Exhaust Temperature Monitoring

● Normal Range:
 ● The normal exhaust temperature of the host should be between 85°C and 97°C.
● Warning Alerts:
● A warning alert is triggered at 103°C.
● The alarm will stop operations at 109°C.

6. Pre-Start Check
● Important Confirmation:
● Before starting the air compressor, ensure that the exit valve of the unit has been
opened.

5. Cautions for Air Compressor Operation

1. Do not touch pipes or components of any compressor during operation.
2. Use only hose fittings and connections of the correct type and size.
When venting through a hose or air line, ensure the open end is secured. If the open end
is placed randomly, it may move suddenly and cause injury. Before disconnecting the
hose, make sure it is fully depressurized.
3. Remote Control Safety:
Personnel who turn on the power of the remote control machine should take adequate
precautions to ensure that no one is inspecting or operating the machine. Corresponding
notifications should be posted on the remote starting device.
4. Avoid Inhaling Hazardous Air:
Do not operate the machine when it is possible to inhale flammable or toxic air, vapors,
or particles.
5. Operating Limits:
Do not operate the machine below or above the rated limit.
6. Door Safety:
Keep all doors of the machine frame closed during operation. These doors may only be
opened briefly for routine inspections and other operations. When opening doors, wear
ear protectors. On uncompressed compressors, wear ear protectors around the machine.
7. Hearing Protection:
Personnel who stay in an environment or house where the sound pressure level reaches or
exceeds 80 dB (A) should wear ear protectors.
8. Air Quality Precautions:
If the hot cooling air discharged from the compressor is used in an air heating system (for
example, to warm a work room), take precautions to prevent air pollution and possible
contamination of respiratory air.
9. Sound Insulation:
Do not disassemble or tamper with any sound insulation material.
 10. Safety Devices:
Do not disassemble or tamper with the safety devices, protective devices, or insulators
installed on the machine. One or more pressure relief devices should be used as necessary
to protect each pressure vessel or auxiliary device installed outside the machine and
containing air pressure in excess of atmospheric pressure.

Fault Cause Solution

1. Check controller fuse

1. “Power-on” indicator is
No control voltage 2. Check transformer secondary
not on
winding control voltage

Check according to the display

Control circuit is cut off
2. Controller trips information. Reset controller to zero.
by safety device
No further check not required.

1. Check cooling oil level

2. Check cooling oil for cleanliness

3. Air compressor stops at Lack of circulation of 3. Check cooling oil system for
high temperature cooling oil leakage

4. Check high-temperature control

valve

Thermistor resistance fault

Poor connection with
protection at high temperature
 environment. Unit stops due to
electrical device
open/short circuit.

1. Check if cooling flow is blocked

at:

- Intake grid

Poor cooling effect - Cooling fins

- Exhaust port

2. Check whether air guide pipe (if

any) has an appropriate size

Ambient temperature is
Improve ventilation in the air
very high (higher than
compressor room
46°C)

1. Check actual working pressure;

reduce setting value if too high.
4. Machine stops Thermal overload relay
2. Cut off power supply to check
automatically, with “motor trips due to too large
whether motor can run smoothly.
overload” shown current
3. Check pressure reduction of
separating core
 2. Check whether main power
voltage reduces to below rated value

5. Machine stops
automatically, with “pressure Isolating valve is closed Open the isolating valve and restart
is too high” shown

1. Check loading solenoid valve

Low efficiency of gas 2. Check unloading solenoid valve

exhaust system and dismantle for cleaning if
necessary

6. Air compressor pressure Check for leakage and whether gas

Too much gas
cannot increase to rated supply valve is opened; assess if gas
consumption
pressure consumption is large

Check the tripping pressure setting

Tripping pressure is low
value

1. Cut off all power supplies, then

7. Air compressor is not Intake valve is not check whether the intake valve can

loaded opened be opened freely.

2. Check the stepper motor

 1. Check intake valve

2. Check the stepper motor

3. Check tripping pressure / rebound

8. Lack of gas supply in air
pressure setting values
compressor

4. Check air intake filter for

pollution; if blocked, indicator shall
be on

9. Large consumption of
Oil return pipe blocked Remove impurities
cooling oil

Oil separating core

Replace oil separating core
damaged

1. Working cycle too fast – increase

10. Cycle is fast, or air
Loading/unloading air volume in system
cylinder cannot exhaust gas
cycle is fast 2. Switch Intellisys controller to
to unloading pressure
show adjusting working mode

Min pressure valve is Dismantle the valve to check, and

blocked when opening repair it if necessary

11. When the air compressor Min pressure valve is Dismantle the valve to check, and
is loaded continuously,
blocked when closing repair it if necessary
safety valve will be opened

Check the setting value and rated

Safety valve failed
pressure of safety valve

If machine is a water (seawater)

cooled unit, check whether it is
12. Machine stops
filled with cooling water.
automatically; too high Poor cooling effect
Check whether water-cooled system
temperature shown
is charged with air and whether filter
is blocked.

7.Maintenance of air compressor

Maintenance Task Details

7.1 Regular Checks

1. Protective Devices All protective devices are in place and securely secured.

2. Hoses and Pipes All hoses and/or pipes in the machine are in good condition, safe and
 reliable, free of wear and leaks.

3. Fasteners and All fasteners are tightened and all electrical leads are safe and
Electrical Leads orderly.

Safety valves and other pressure relief devices are not blocked by
4. Safety Valves
dirt or paint.

The exhaust valve and the air pipe network (pipes, couplings,
5. Exhaust Valve and
manifolds, valves, hoses, etc.) are well-maintained without wear or
Air Pipe Network
abuse.

The controller menu logs the running hours of the compressor,

7.2 Controller Menu which cannot be modified; record this for future maintenance
reference.

Maximum time: 2000 hours; clean every 600-700 hours by blowing

Air Filter Replacement compressed air from inside out; replace when pressure difference is
large.

Maximum time: 2000 hours; replace timely upon machine alarm;

Oil Filter Replacement
lubricate the contact surface before installation.

Oil Separation Core Theoretical usage time: 4000 hours; check for dust; remove internal
 oil tubing before opening the cover.

Grease every 2000 hours for front and rear bearings of the main
Main Motor Bearings
motor.

Compressor Oil Change every 8000 hours or annually; during oil change, replace oil
Replacement filter and oil separation core to avoid contamination of new oil.

Use of Original Spare To ensure reliable operation of the compressor, use original factory
Parts spare parts.

S/N Period Maintenance Contents

Within 24h Visually check the unit for leakage, dust clogging, or abnormal
1
after startup noise/vibration; if in doubt, please contact Ingersoll Rand.

2 Daily - Check cooling oil level, and add if necessary.

- When warning is shown on oil separating core, check pressure

difference; replace if it decreases to zero or exceeds 1 bar (15 psig).

- Check air filter.

 - Check hoses and all fittings for leaks.

- Check records; if consumables have reached the replacement cycle,

they must be shut down and replaced.

- Inspect records; if the main engine exhaust temperature reaches or

approaches 98 °C, clean the oil cooler.

3 First 150h Replace oil filter element.*

- Check high-temperature protection switch (standard: 109 °C).

- Check exhaust temperature sensor (standard: 109 °C); sensor should

alarm at 106 °C.

- Check cooler for impurities; blow off with compressed air or wash
under pressure if necessary.

- Check float mechanism in water separator; clean if necessary.

4 First month
- Clean the aftercooler.

- Check all wire connections and tighten them.

- Check AC contactor head.

- Clean dust from motor's suction surface and housing surface.

- Clean the oil return filter.

 - Manually open safety valve to check normal function, releasing a
small amount of air.

- Check all hoses for aging, cracking, or hardening.

- Fill main motor with grease.

- Clean main motor and fan motor.

Every three
5
months - Replace coolant.

- Replace oil filter.

- Clean oil cooler.

- Check minimum pressure valve.

- Check sensor.

Replace oil filter. *If resistance indicator on electrical component

6 Every 2000h
board is on, replace immediately.

Every 2000h - Sample coolant for testing.

7
/ six months - Check oil return hole filter for clogging; clean if necessary.

Replace air filter. If resistance indicator on electrical component board

8 Every 4000h
is on, replace immediately.
 - Comprehensive check of oil separation cylinder; inspect all outer
surfaces, welds, and joints for corrosion, mechanical damage, leakage,
or other issues.

Yearly / - Replace coolant (Ultra Coolant).

9
every 1000h
- Check check valve.

- Check cooling fan.

- Check hydraulic cylinder limit device.

Every 4000h
10 Check discharge solenoid valve for fatigue; replace seals if necessary.
/ six months

Every Lubricate main motor bearings according to information on the motor

11
2000 /4000h data nameplate; if in doubt, please contact Ingersoll Rand.

Every 8000h Replace super cooling oil; whichever occurs first. Replace oil
12
/ two years separating core and oil filter.

Every 4
13 Replace all hoses.
years

Every 6 - Inspect oil separation cylinder; remove cover plate and connectors,
14
years /6000h thoroughly clean interior and check all inner surfaces and welds.
 For water-cooled units, check inlet pipe filter; remove accumulated
15 Monthly
impurities if any.

7.4 Maintenance Items and Operation Method

1. Check Electrical Connections:
Inspect the contact and insulation resistance of the electrical parts of the screw-rod air
compressor. The electrical components are divided into the main circuit, control circuit,
and signal transmission (temperature and pressure sensors) circuit. Due to vibrations
generated during operation, some wire connectors may loosen over time. A loose wire
connector can prevent the unit from starting and, in severe cases, lead to protection
failures, arc short circuits, or electric shock. Therefore, the electrical components should
be checked regularly. When checking, use your hand to gently shake each wire to feel for
tightness; loose connections should be tightened. Additionally, use a megohmmeter to
check the insulation of the motor and equipment to ground. The insulation resistance
should be maintained at more than 500 megohms; otherwise, drying or maintenance
treatment should be performed.
2. Replace Motor Grease:
Replace the motor grease every 8000 hours of operation. If parameters are provided in
the equipment manual, those should be followed. Proper lubrication at both the front and
rear ends of the motor is essential for ensuring longevity and normal operation; therefore,
grease should be injected regularly. The type of grease should be selected according to
the parameters provided by each manufacturer.
3. Clean Relief Valve (Intake Valve)
The relief valve consists of several components: the valve body, valve core (piston), gas
manifold, solenoid valve, and proportional valve (capacity regulating valve). Its primary
functions are to control the loading (heavy load) and unloading (empty load) of the air
compressor, as well as to provide proportional control for capacity adjustment.
Additionally, it prevents lubricating oil from spraying out when the air compressor shuts
down.

Disassembly Steps:
1. Remove the hose connecting the relief valve to the air filter.

Clean Relief Valve:

 ● Use soapy water, diesel, clean gasoline, or other appropriate cleaning agents based on the
level of dirt. Generally, soapy water or diesel is recommended for this purpose.

Remove Solenoid Valve:

● Detach the solenoid valve and check whether the O-ring and sealing plate inside need
replacement.
● Reminder: If you are unfamiliar with the intake valve, note where each
component was disassembled to avoid mistakes during reassembly.
●
● If replacement is not necessary, place disassembled screws, O-rings, seals,
electromagnetic rods, cores, and other components into a prepared container with an
appropriate cleaning agent for soaking.
● Note: When using gasoline or other solvents as cleaning agents, do not soak
rubber products like O-rings for too long to avoid corrosion.

Remove Proportional Valve:

● Detach the proportional valve from the valve body and unscrew the adjustment nut. Make
marks on the screws before unscrewing them to avoid significant deviations during
reassembly.
● Remove the valve core, O-ring, U-ring, and spring; check whether O-rings and U-rings
need to be replaced. All seals and springs removed from the screw air compressor must
be inspected.
● Soak the dismantled components in a cleaning agent.

Demolition of Gas Manifold:

● Remove the manifold block from the valve body. There are air holes on four sides of the
manifold block that help dredge when the integrated gas circuit is blocked.
● Unscrew the sealing nut on the air hole and place it in the cleaning agent along with the
manifold for soaking.

Remove Valve Core of Relief Valve:

● Use circlip pliers to remove the clamp spring located at the joint between the valve core
and the valve body.
● Then use a pipe wrench to unscrew the valve core and remove the cylinder, valve disc, O-
ring, U-ring, and spring; soak them in a cleaning agent.
● Next, take out the air intake valve from the valve body and place the entire valve body
into soaking. The disassembly process of the relief valve is now complete.
Cleansing:
● If there is heavy dirt in the intake valve, replace it with a fresh cleaning agent during
cleaning.
● During this process, wash cleaner parts first and then tackle dirtier parts. Rinse cleaned
parts again with clean water to prevent corrosion that could shorten their service life.
● Parts washed with clean water should be placed in a clean area to dry to avoid rusting of
iron-containing components.
When cleaning the valve plate and its contact area with the valve body, pay attention to
surface flatness. Clean thoroughly; if necessary, replace it; otherwise, it may cause
starting issues under load for the air compressor (large screw air compressor units may
fail to start under load).

Installation Components:
● Component installation should follow reverse steps from disassembly.
● Note that when installing components, apply an appropriate amount of oil to sealing rings
and moving components to facilitate easier installation of sealing rings and ensure more
flexible movement of parts.

Note:
Since there are many parts in the relief valve, if you do not remember each part's position,
you can clean one part at a time after removing it before reinstalling it. However, do not
install any part back onto the valve body until all parts have been cleaned; then assemble
them together onto the valve body.
After completing the entire cleaning process of the relief valve, set it aside until it is
ready to be installed back into the air compressor.

4. Clean Minimum Pressure Valve (Pressure Maintaining Valve)

Composition: The minimum pressure valve is composed of the valve body, valve core,
adjustment nut, spring, and sealing element.
Function: The role of the minimum pressure valve is mainly to produce the internal pressure of
the unit, promote the circulation of the lubricant, and meet the working pressure of the relief
valve. Additionally, the minimum pressure valve functions as a one-way valve to prevent the air
in the gas tank from flowing back to the air compressor during unloading operations.
Disassembly: The structure of the minimum pressure valve is very simple. Unscrew the nut
connecting the valve core and the valve body to remove the internal components. The minimum
pressure valve core of small units is built into the valve body; simply remove the body cover to
access all internal components.
Cleaning: Clean the minimum pressure valve using the same method as for cleaning the relief
valve.
Assembly: Assemble the components according to the reverse steps of disassembly. Due to its
simple structure, detailed assembly instructions will not be provided here. However, it is
important to ensure that if there is a U-ring inside, its orientation is correct during installation.
Note: After completing the entire cleaning process of the minimum pressure valve, set it aside
until it is ready to be installed back into the air compressor.

⑤ Clean Oil Return One-Way Valve

Composition of One-Way Valve: The one-way valve consists of a valve body, steel ball, ball
seat, spring, and other components.
Function of Oil Return One-Way Valve: The oil and gas mixture compressed by the main engine
is first separated by centrifugal force in the oil and gas tank. Because the weight of the oil is
greater than that of air, most of the oil in the solid oil and gas mixture falls to the oil tank through
centrifugal force. The air compressor returns to the main engine under the action of internal
pressure for a lubrication cycle, and the compressed air containing a small amount of oil is
separated again by the oil separator. The lubricating oil separated by the oil separator will fall to
the bottom of the device. To prevent this portion of oil from being carried away with the
compressed air, a tubing is inserted into the bottom of the oil separator. Through internal
pressure, this part of the oil is directly introduced into the main engine for lubrication. The one-
way valve, referred to as the oil return one-way valve in screw air compressors, ensures that oil
from the oil separator is successfully returned to the main engine without allowing oil from the
main engine to flow back into the oil separator.
Disassembly of Oil Return One-Way Valve: The structure of the minimum pressure valve is very
simple. Unscrew from the connection on the valve body to remove the components inside.
Cleaning Oil Return One-Way Valve: Clean the valve body, spring, steel ball, and ball seat with
a cleaning agent. If there is a filter inside the one-way valve, clean it together if necessary.
Assembly of Oil Return One-Way Valve: Assemble the one-way valve according to the reverse
steps of disassembly.
Note: After completing the entire cleaning process of the one-way valve, set it aside until it is
ready to be installed back into the air compressor.

⑥ Clean Temperature Control Valve

Composition of Temperature Control Valve: The temperature control valve consists of the valve
body, valve core, temperature sensor, spring, and other components.

Function of Temperature Control Valve: The temperature control valve has a thermostatic
control function. When the temperature measured by the sensor is below the action value
(generally around 71 degrees Celsius), the lubricating oil flows directly from the oil and gas tank
back to the engine. When the oil temperature measured by the sensor exceeds the action value,
the thermal element of the temperature control valve activates, pushing the valve core to open its
bypass valve. This allows the lubricant to enter the cooler for cooling. The higher the
temperature measured by the temperature sensing element, the wider the bypass valve opens.
The cooled lubricant is then returned to the engine.

Disassembly of Temperature Control Valve: The surface of the screw air compressor's
temperature control valve has a cover with a screw hole. Find a suitable nut to screw into the
cover, then use circlip pliers to remove the cover. Use pliers to pull the nut just screwed in to
remove all internal components.

Cleaning Temperature Control Valve: Clean all parts of the temperature control valve using the
same method as for cleaning the relief valve.

Assembly of Temperature Control Valve: Assemble the components according to the reverse
steps of disassembly.

Note: After completing the entire cleaning process of the temperature control valve, set it aside
until it is ready to be installed back into the air compressor.

⑦ Clean Water-Cooled Cooler

A. Open the Inlet and Outlet of Cooling Water Pipes:
Open the inlet and outlet of the cooling water pipes.
B. Soak in Cleaning Solution or Flush with a Pump:
Soak in the cleaning solution or flush with a pump cyclically (back flushing will have a better
effect).
C. Rinse with Water:
Rinse with water.
D. Install Cooling Water Inlet and Outlet Pipes:
Install the cooling water inlet and outlet pipes.
When the oil cooler has significant scaling and the above cleaning methods are not effective, you
can remove the oil cooler separately, open both end caps, and use a special steel brush or other
tools to remove the scale.
When cleaning the medium side of the cooler does not effectively reduce the temperature, the
screw air compressor needs to clean the oil side as follows:
E. Open Inlet and Outlet Pipes:
Open the inlet and outlet pipes.
F. Soak in Cleaning Solution or Flush with a Pump:
Immerse in cleaning solution or flush with a pump cyclically (back flushing will have a better
effect).
G. Rinse with Water:
Rinse with water.
H. Dry with Dry Air or Remove Water with Dehydrated Oil:
Dry with dry air or remove water using dehydrated oil.
I. Install Inlet and Outlet of Oil Pipes:
Install the inlet and outlet of the oil pipes.

⑧ Clean Water-Vapor Separator

The structure of the screw air compressor water-vapor separator is similar to that of the oil and
gas tank. The air intake is designed against the wall, utilizing centrifugal force for separation.
Due to the weight differences between water and gas, this design effectively separates moisture
from compressed air.
Water and Gas Separator Cleaning:
Open the water separator cover and immerse it with a cleaning agent.

⑨ Calibrate All Parameters

After all components have been cleaned and dried, begin installing them back into the air
compressor. Once all components are installed, check again for any omissions, and clean any
tools used during installation.
After completing these steps, ensure that everything is functioning correctly before resuming
normal operation of the air compressor.
Note: The above maintenance should be done after the equipment is confirmed to be free of
electricity and pressure

7.5 Maintenance Program

(1) Cooling Oil Check Procedure:
Cooling oil level shall be checked daily. The cooling oil level sight glass is located at the side of
the oil separator cylinder. When the air compressor is running under loaded conditions and the
cooling oil temperature is at normal working levels, the cooling oil level should be between the
middle and top of the sight glass.
(2) Cooler:
The cooler shall be checked monthly for oil dust accumulation on the outer surface. The core
should be cleaned with compressed air, which may contain a non-flammable safety solvent.
(3) Oil Filter Replacement Procedure:
● Use appropriate tools to loosen the filter element.
● Remove the filter element from the housing.
● Place the old filter into a sealed bag for safe disposal.
● Clean the mating surface of the housing.
● Take a new IR filter spare part from the packaging box.
● Screw in the new filter until the seal touches the housing, then tighten it half a turn by
hand.
● Check the cooling oil level and add if necessary.
● Start the air compressor and check for leaks.
●

(4) Cooling Oil Replacement Procedure

It is recommended to drain the oil just after the air compressor stops. At this time, the oil liquid
is easily drained with dirty matter floating in it.

Warning: Be very careful when draining hot oil.

● To drain the cooling oil, an exhaust valve should be set under the oil separating cylinder.
Hoses are installed under the valve to directly drain oil into a container.
● Open the gate valve to drain all cooling oil into an appropriate container.
● Close the valve and add new oil into the air compressor.
Caution: Do not mix SSR ULTRACOOLANT super cooling oil with other oils.

● Start the air compressor and check for leakage.

 ● Check the cooling oil level and add if necessary.
● Dispose of waste oil according to local and government regulations.

(5) Air Filter Replacement Procedure

Warning: Do not remove the air filter before ensuring that the air compressor has been stopped
and all air pressures have been released from the system.

● Remove the butterfly nuts on the air filter cover and then remove the shell cover.
● Install a new filter in reverse order of dismantlement.

(6) Oil Separating Core Replacement Procedure

● Remove the top panel to access the top of the oil separator cylinder.
● Disconnect the oil return pipes from the main machine, loosen connectors that fix the oil
return pipe on the oil separator cylinder, and then remove the oil return pipe.
● Remove hoses and the minimum pressure valve from the exhaust system.
● Remove lock bolts that secure the cover to the cylinder and then remove the entire cover
assembly.
● Take out the damaged oil separating core and place it into a sealing bag for safe disposal.
● Clean surfaces of the sealing gaskets on both the cylinder and cover.
Caution: Do not use any form of sealant on the surfaces of the oil separating cylinder and its
cover.

Caution: Do not remove iron nails on the anti-static sealing gaskets of the oil separating core, as
they serve a grounding function.

● Install a new oil separating core.

● Assemble in reverse order of disassembly.
● Start the air compressor and check for leakage.

(7) Main Machine Bearings

Main machine bearings shall be lubricated with cooling oil in the air compressor, without any
maintenance.

(8) Motor Bearings

Remove protective covers after cleaning the oil nozzle. Add an appropriate amount of grease.
Cover with the protective cover and remove any excessive grease around.
Specification of Motor Bearing Grease: Use ESSO UNIREX N3 or equivalent grease.
Caution: Do not add too much motor bearing grease, as this may cause motor failure.
Caution: Ensure that no dust and/or dirt enters during the grease application process.

(9) Check Procedure in High Temperature Environment

Regularly check the exhaust temperature sensor according to the following method:
● Water-Cooled Unit: Cut off the cooling water supply.
● The unit shall trip at 109°C.
Caution: Do not exceed this exhaust temperature under any circumstances. If the machine does
not trip, it indicates a fault. Immediate investigation is required.
Record the unit shutdown temperature for future comparison.

7.6 Maintenance Items and Quality Requirements of Air Compressor

7.6.1 Overhaul Process and Maintenance Adjustment of Screw Air Compressor

(1) Adjustment of Inlet Butterfly Valve
The adjustment for the butterfly valve shall be quick acting, and when loading, the compressor
discharge pressure should be between the upper and lower limits of the pressure switch. The
adjustment steps are:
● A: Remove bolt A and loosen clamp screw B.
● B: Turn the intake valve shaft counterclockwise until the valve plate is in the closed
position. While ensuring that the valve plate is closed, adjust the connecting arm to
approximately a 60° angle so that it just touches stop D. Now, tighten clamp screw B.
● C: Adjust the intake valve adjuster rod G.
● D: After ensuring that the adjusting lever G on the regulator body is against the stopper,
adjust the length of the ball bearing J on the inlet valve rod end until the connecting arm
F end bolt easily enters the connecting arm F. At this time, the inlet butterfly valve is
closed, and tighten the bolts.
(2) Pressure Switch Adjustment
The adjustment method involves first adjusting the lower limit value, then adjusting the
switching difference, which subsequently determines the upper limit value. The switching
difference is generally 1.7 × 10^5 Pa. Note that the upper limit must not exceed the maximum
compressor discharge pressure. The adjustment steps are:
● Open the isolation valve to allow the control system to sense the line pressure.
 ● Set the normal/no-load switch to the "idle" position and adjust the control selector switch
to the "ON/OFF" control position.
● Adjust the batch needle of the switching adjustment knob to the middle scale.
● Start the compressor and set the normal/no-load switch to the “normal” position. If the
line pressure is lower than the pressure switch's lower limit setting, the compressor will
load. Conversely, adjust the pressure switch value adjustment knob until the compressor
is loaded. If necessary, vent the compressed air system to facilitate loading.
● Slowly close the isolation valve and allow the line pressure to rise to exhaust pressure.
● Carefully adjust the switchover adjustment knob until the compressor is empty. When the
pressure switch disconnects, the compressor will idle, and the deflation solenoid valve
will release air.
● Vent the compressed air system to verify that the switch action meets usage requirements.
● Note that whether increasing or decreasing the switching difference will affect both
maximum discharge settings and circuit disconnection. Repeat steps 5 and 6 as necessary.
● Adjust the maximum discharge pressure accordingly.
● Lock both ends of the lock; this indicates that adjustments are complete.

(3) Overhaul of Oil Filter Core

● Unscrew the oil filter cartridge with a suitable tool and place it in the designated waste
container.
● Take out the new oil filter, check that the sealing gasket is not damaged, and apply a
small amount of grease to the sealing ring.
● Screw the new oil filter lightly in and tighten it with a tool.
● Start the compressor, check for leaks, and then put it into use.

(4) Air Filter Element Replacement

● Park the compressor.
● Loosen the wing nuts (ingot nuts) on the top of the intake filter housing and remove the
top cover to expose the filter element.
● Carefully remove the old filter element, taking care not to let dust fall into the intake
valve.
● Thoroughly clean the filter housing and dry all surfaces.
● Install the intake filter's top cover.
● If there is a problem with the gasket between the filter elements, it should be replaced.
● Tighten the wing nut.
● Put the unit into operation.

(5) Lubricant Replacement

 ● Empty the oil separator bowl, the oil cooler, and lubricate all the lowest points in the
piping system.
● After the remaining oil is drained, close all drain ports to ensure good seals.
● Replace the oil filter cartridge.
● Inject new lubricant into the oil separator bowl. Add approximately 290 liters of oil.
● Tighten the filler plug, start the compressor, and stop after a short run.
● Check the oil level. If it is not in the middle of the oil level gauge, continue adding oil
until it reaches the middle of the gauge.

(6) Oil Separator Core Replacement

● Disconnect the return line on the compressor main unit.
● Loosen the return hose throttle head on the top cover of the oil separator and pull out the
return hose assembly.
● Remove the pipe from the top cover of the separator. Attach a label indicating the pipe
connection if necessary.
● Use a suitable wrench to remove the bolts securing the top cover and lift it off.
● Carefully lift the separator core out of the barrel and dispose of the worn core.
● Clean the sealing surfaces of both gaskets on the top cover and cylinder. Be careful
during cleaning to prevent debris from old gaskets from falling into the oil separator.
● Inspect the interior of the oil separator to ensure no debris, such as rags or tools, has
fallen inside. Check that the new gasket is undamaged and ensure that it contacts both
antistatically charged staples and metal. Insert the new core and align it with the central
axis of the tank.
● Place the top cover in its normal position and tighten the bolts. Use a crisscross pattern to
tighten them stepwise to prevent one side of the top cover from being overly tightened.
Incorrect tightening can lead to leaks.
● Insert the return pipe into the oil separator, ensuring it is 4 mm from the bottom of the oil
separator core, then tighten the throttling fitting.
● Put the tube back in its original position.
● Start the unit, check for leaks, and put it into use.

7.6.2 Overhaul Period

● Class A Overhaul: Every 2 years
● Class B Overhaul: Every 6 months