RECIPROCATING COMPRESSOR PRESSURE PULSATION DRUMS

1AUGUST 2014

2

RECIPROCATING COMPRESSOR PRESSURE PULSATION DRUMS

AUGUST 2014

3

GAS SCRUBBERS ON THE SUCTION SIDE

The function of gas scrubber is to remove any liquid droplets or solid particles from the gas before it enter the compressor

AUGUST 2014

GAS SCRUBBER

1. Scrubbers should be placed on all suction lines

2. These vessels should be equipped with a separating element to

remove liquid

3. Scrubbers should be equipped with:

Gauge level glass

Automatic drain system

Shut down device to shut the compressor down on high liquid

level

4AUGUST 2014

5

ROTARY POSITIVE DISPLACEMENT COMPRESSORS

SCREW COMPRESSOR

AUGUST 2014

6

CENTRIFUGAL COMPRESSOR - HOW IT WORKS?(1)

AUGUST 2014

7

CENTRIFUGAL COMPRESSOR - AXIAL SPLIT CASING

AUGUST 2014

8

COMPRESSOR CASING COMPONENTS- DIAPHRAGMS

DiaphragmDiffuser channel

Return channel

AUGUST 2014

9

CENTRIFUGAL COMPRESSOR ROTOR (5 STAGES)

AUGUST 2014

CENTRIFUGAL COMPRESSOR APPLICATIONS

Advantages of centrifugal compressors:

1. They have fewer rubbing parts

2. Relatively energy efficient

3. High flow rate

4. Continue flow, no pressure pulsation

Applications:

Gas transportation pipelines

10AUGUST 2014

COMPRESSOR SELECTION

The main parameters involved in compressor selection

1. Final discharge pressure

2. Flow rate

3. Vibration level & noise

4. Lubrication

5. Compressor valve design

6. Control system

7. Initial cost & running cost

11AUGUST 2014

PUMPING STATION

Components of pumping station

1. Suction and discharge headers

2. Pumps- could be centrifugal pump or plunger pump

3. Valves (throttling, isolation, non-return and safety)

4. Pressure pulsation dampeners (plunger pump)

5. Receiving tanks

6. Metering station

7. Instrument air system

8. Strainers (duplex strainers & temporary strainers)

12AUGUST 2014

WATER HAMMERING

What is water hammering?

It is a pressure wave caused by the kinetic energy of a fluid in

motion when it is forced to stop or change direction suddenly.

What is the effect of water hammering?

It will cause pressure wave which could cause pipeline to break if

the pressure is high enough.

13AUGUST 2014

WATER HAMMERING

Possible causes of water hammering:

1. Unexpected(emergency) switching-off of the power supply.

This will cause sudden check valve closure

2. Sudden valve closure. To avoid quick valve closure use valve

actuator which make the operation of the valve very slow

14AUGUST 2014

WATER HAMMERING

How can we reduce the effect of water hammering?

1. Low fluid velocities, the fluid velocity should be less than 1.5 meter/ second

2. Slow closing valves

3. High pipeline pressure rating (expensive)

4. Good pipeline operation control (start up and shut-down procedures for the

pumps)

5. Water towers

6. Air vessels

7. UPS (uninterruptible power supply)

8. Pumping station bypass

15

FACTORS CONTRIBUTE TO WATER HAMMER

1. Improperly sized piping in relation to water flow velocity

2. High water pressure with no pressure reducing valve

3. Straight runs that are too long without bends

4. Poor strapping of piping system to structure

5. No dampening system in place to reduce or absorb

shockwaves

16AUGUST 2014