Critical Projects

 
Critical Projects are those projects that are more complex and have a greater potential for operational issues if special attention is not applied early in the project.  Ariel would like to assist in the review of critical projects and therefore has included a flag in the performance software identifying the projects that fall in this category.
 
Critical Projects are defined by a review of:
 
Application Type:

 

Gas Transmission

Wide Range of Operating Conditions

Wide Range of Capacity Control Steps including Single Acting Cylinders

Large drivers

Difficult Valve Selection due to the Wide Operating Range

Complex Acoustic Responses

 

Storage Injection and Withdrawl

Higher Pressures

Attention to Cylinder Lubrication

Water cooled packing cases

Wide Range of Operating Conditions

Difficult Valve Selection due to the Wide Operating Range

 

PRC (Petroleum / Refinery / Chemical)

Industrial Gasses

More Stringent Specification Limitations

New Customer base

 

Equipment Type:

 

Large Frames

JGU, JGZ, KBB and KBV

Some JGC and JGD

Large Two Throw Frames

Requiring Special Tools for Maintenance

 
Pipeline Cylinders

High Flows with Large Piping

High Frequency Components

Large, Low Natural Frequency Cylinders

 

VS Forged Steel Cylinders

High Pressure

Lubrication

Water Cooled Packings

Available Tailrods

 

Driver Type:

 

Electric Motor

Unique Installations

Shaft Sizing Restrictions (see Packager's Standards)

Always Requiring Torsional

Often Requiring Torsional Detuning Devices (flywheels, detuners, special couplings...)

 

VFD (Variable Frequency Drive)

Unique Installations

Shaft sizing restrictions

Always Requiring Torsional

Often Requiring Torsional Detuning Devices (flywheels, detuners, special couplings...)

Wide range of speeds, often with blackout ranges due to torsional response

 

Large Gas Engines

High horsepower - high excitation forces

Longer drive trains

Often Requiring Torsional Detuning Devices (flywheels, detuners, special couplings...)

Some larger engines designed for power generation may require special couplings and attention to torsional results

 

Gear Boxes

Difficult to detune torsionally

Most often requiring special couplings

Axial and Lateral Alignment Concerns including Thrust Limitations

 

Location:

Offshore and FPSO

Limited Access

Limited Space for Maintenance

High Visibility

International Destinations

Less Support Infrastructure in some Regions

 

Other:

Sour Gas

Proper Materials

Purge and Vent Systems

Pneumatic Fixed Volume Clearance Pockets

Supply and vent lines

Complex controls

 

Project Reviews:

 

Many Critical Projects can be successful with a comprehensive review of the system during different phases of the project:

 

Budget and Quotation Phase

Regional Sales Managers and Applications Engineering can provide assistance in selection

 

Order Phase

Order Entry can provide assistance with scope of supply

Applications Engineering can provide assistance with documentation, including torsional data

Tech Services can provide assistance with packaging design for maintenance support and vibration avoidance

 

Installation and Start-Up Phase

Tech Services can provide assistance with installation review, start-up check list review, review of vibration concerns

 

 

Torsional Providers:

 

The success of the torsional analysis depends heavily on the modelling of the equipment and operating range of the compressor.  A torsional provider must be familiar with moderate to high speed reciprocating compressors and must be provided with the full range of operation of the compressor.  The operating range is to include part load cases, cases with single acting cylinders and speed variations.  Familiarity with Ariel compressors is quite helpful in understanding aux end amplitudes, the availability of the torsional data (mass elastic data, torque effort data and fourier coefficient data) and availability of specific flywheels, detuners and internal flywheels.

 

 Acoustical and Mechanical Providers:

 

Familiarity to moderate and high speed reciprocating compressors will aid in the successful acoustical and mechanical analysis.  Some larger skids and many platform mounted skids may require a skid analysis to ensure vibration levels and stress levels of skid, piping and vessels are acceptable.

 

Torsional and Acoustical analyses may have interfering recommendations.  More complex the operating ranges have a greater chance of interference between the torsional, acoustical and mechanical systems.

 

 

 

 

 

Ariel Corporation Application Manual  
16 June 2006