Welcome to the John Crane Lifecycle Cost Calculator

Scenario 1

Traditional oil seal and the associated seal support system with seal leakage vented to atmosphere.

Scenario 2

Traditional oil seal and the associated seal support system with seal leakage vented to flare.

Scenario 3

Traditional oil seal and support system fitted with an enhanced leakage recovery system which captures seal leakage and redirects it to an alternative value adding use.

Scenario 4

Non-contacting dry gas seal and the associated seal support system venting to atmosphere.

Scenario 5

Non-contacting dry gas seal with a seal gas recovery system scavenging atmospheric emissions and returning them to the compressor.

Upon completion of all the input information, click the “Submit” button. The results will then be displayed.

The calculated results are provided for each of the 5 different sealing technologies and information is grouped as follows:

Annual Operating Costs of the compressor shaft sealing system

The annual operating costs include both spare parts and direct labor to operate the shaft sealing system together with the cost of parasitic losses such as the value of the gas leaked, the cost of the energy that was consumed to compress the gas that has leaked, etc…

One-time Costs

This is a summary of the costs required to implement (retrofit)each of the shaft sealing solutions. Payback is calculated from the total retrofit cost versus the reduction in annual operating costs from a traditional oil seal and the associated seal support system with seal leakage vented to tmosphere.

Present Value Calculations

A summary is provided of the retrofit costs together with the annual operating costs discounted to present value over the period of time the compressor is expected to remain in service.

Power Consumption Calculations

Energy can be a large component of the lifecycle cost of any shaft sealing system. The energy calculated not only includes the direct power requirements to overcome the friction of the shaft seal, but also looks into the energy requirements needed to operate each particular sealing scenario. t does not include the energy requirements to operate the compressor driver.

Carbon Footprint

The summary and total carbon dioxide equivalent emissions include the emissions resulting directly from release of methane to the atmosphere (using the Global Warming Potential inputted by the user in the Carbon Footprint page) together with the emissions resulting from the energy expended o operate the shaft seal and support system including any parasitic losses for each of the shaft sealing solutions.

Total Estimated Lifecycle Cost

The total estimated lifecycle cost is the sum of the costs associated with implementing the shaft sealing solutions and the annual operating costs discounted to present value over the period of time the compressor is expected to remain in service.

Graphs

Graphs are provided indicating the relative total lifecycle cost of each sealing technology over varying time spans and the accumulative carbon dioxide equivalent emissions over time.

CfsOperating Cost of Lost Energy from Seal Friction

These are the costs associated with the energy required by the compressor driver to overcome frictional losses of the mechanical seal and any viscous drag caused by the seal oil.

CssOperating Cost of Energy Required to Operate Seal Oil System

These are the costs associated with electrical motors used to circulate the seal oil and forced convection heat exchangers.

ClOperating Cost of Lost Energy and Product Loss due to Leakage

This is the cost associated with the energy used to compress gas that subsequently leaks out of the compressor casing via the mechanical seal together with the value of the leaked gas

CfpOperating Cost of Lost Energy to Overcome Pipe Friction Due To Oil Contamination

This is the cost of the energy consumed by the compressor driver to overcome frictional losses in the compressor discharge pipeline as a result of contamination of the pipe surface from oil leaked by the mechanical seal into the compressor

CenOperating Cost to Replace Consumed Seal Oil

This is the cost of replacing seal oil that is leaked by the mechanical seal either into the compressor or to atmosphere.

CmMaintenance and Downtime Costs

This is a combination of the cost for parts and labor used to maintain the seal and sealing system on scheduled maintenance events and unscheduled seal or system failures together with any costs associated with lost productivity due to the compressor being inoperable.

CpCost of Process and Purge Gas Used During Compressor Blowdown

This is the cost to of the compressed gas lost together with inert blanket gas used to in order to decompress the compressor and facilitate maintenance on the shaft seals.

CgCost of Gas Seal Separation Gas Consumption

This is the cost of the separation gas used with a gas seal that is injected into the separation seal that is fitted in between the gas seal and the compressor bearings.

CicInitial Purchase Cost

This is the initial cost to purchase the sealing solution, and may include engineering, bid process expenses, PO administration, testing, source inspection, and initial spares as appropriate, provided all scenarios are treated in a similar fashion.

CinInstallation Cost

These costs may include special area preparations, installation and connection of utilities piping systems, electrical wiring and instrumentation, installation of auxiliary systems, and special services required at start-up.

CdDecommissioning and Disposal Cost

This is the cost to dispose the existing seal and/or sealing system that is being replaced by the seal upgrade retrofit. The costs are incurred at the time of the retrofit.

Carbon Dioxide Equivalent Emission

Driver Efficiency

Fuel Net Calorific Value

Miscellaneous Conversion Factors