The Hidden Costs of Compressed Air/Gas Leaks

leaky pipes

Most of the companies we perform audits for do their best to conserve energy.  Most energy engineers realize the high cost of energy drain due  to how much  extra  horsepower air compressors waste while trying to maintain pre-set air

pressures.  Likewise, they realize how costly leaks in their Nitrogen, Utility Air and  steam can  be.

The focus of this article will be not only how leaks can  negatively impact the system but also how leaks can  affect the environment and  quite possibly the wellbeing of the personnel that have  to work around them.

Air Leaks: Negative Impacts on  Process Control

Air leaks can  impact processes negatively.   Control and  pressure reducing valves are  relied upon  to control the manufacturing process.  Precise control is critical to the product  we produce and  to the environments we seek to maintain.   Air operated for heating and  ventilating system needs to accurately control the heating and/or  cooling process.

Loose connections or splits in the tubing can  adversely impact proper  control.   Obviously, a ruptured  diaphragm in a control valve cannot be properly controlled by a computer.  Therefore, it should be apparent that facilities need to perform compressed air /gas leak audits on a regular basis, or make  arrangements with a competent and  professional firm to have  audits periodically performed.

In a compressed air and  gas system there  are  many  critical components that require validation of proper  operational

capabilities.  Non-critical system components likewise need to be scanned and  tested for leakage. They include, but are  not limited to: relief valves, solenoid valves, flange gaskets, thread connections, filter/lubricator/regulators, weld, thread and  quick connection devices.   At any given time, they may not only be wasting energy but sacrificing proper  process control.

Compressed air systems depend on supplying clean dry air to their equipment and  components.  Separators, receiver vessels, compressors and  other  components in a compressed air system depend on drain traps to automatically discharge the condensed water  from the system.  When  a drain trap fails in the closed position it causes a back-up of condensate.  The air fed to system will contain water  that can  be detrimental to the equipment.

Rust, dirt and  corrosion are  additional consequences of not replacing these failed drain traps in a timely fashion.   Ignorance of plugged drain traps also contribute to other  portions of the system becoming adversely affected.  If a drain valve fails in the open position large quantities of energy are  wasted.  Since, most drain traps are  piped into discharge manifolds and  then  to waste drains, it is not generally visually apparent that they might have  failed in the open  position.   Therefore, it is essential that regular ultrasonic tests be performed on these drain traps.

Valves, solenoids and  other  sensitive equipment can  plug or stick in an open  position and  eventually fail.   Many times, the gaskets between banks of solenoids begin to leak when  water  has not been drained from the compressed air system.  Sometimes oil in compressed air systems can  cause o-ring or gasket failures.    If part of the system is outdoors and  is subject to low temperatures, the air lines and  the equipment to which it leads can  freeze.   Once  frozen the portions that freeze can  crack  and  be permanently damaged.   A proper  air leak audit should identify the components that are  causing energy loss.

As you can  see the air/gas system is like a food chain, in that any one  portion of the system that has failed will impact the others.

Gas Leaks: Costly and Dangerous

Other  gases are  quite a bit more  expensive than  compressed air.   The rule of thumb  for contrasting a compressed air leak vs. a nitrogen leak, for example, is that typically, nitrogen is ten times more  expensive than  air.

So,  who wants to live with even  tiny nitrogen leaks?

The cost of living with many  nitrogen leaks will without doubt  take  a big bite out of your profits.  If the leaking gas is volatile, such as natural gas, identifying and  repairing the leak becomes an urgent  priority.  In one  plant, we found 22 natural gas leaks in one section of piping near  the ceiling.   The gas line was feeding an oven  that had  ignition points every  ten feet along the length of the equipment.   The potential safety hazard of these leaks far outweighs the actual cost.  Should an explosion have  occurred, aside from the physical harm  it could cause workers in the immediate area, it would have  shut down the plant for quite some time.

In a parts manufacturing plant, we found a huge  argon  leak.  The feed line had  a hairline split that was carrying the gas to a welder. Inert gases such as argon,  helium, and  nitrogen are  non-toxic and  do not burn or explode. However,  they can  cause injury or death at high concentrations by displacing oxygen  in the air. Should oxygen  levels fall too low, individuals in the area or entering the area can  lose consciousness or die from asphyxiation.

It is crucial that leaks be found and  corrected before a small problem becomes a severe problem.

In  our  business, there is old  truism: “everything leaks, it is just a matter of when.”

Leaks are  Like a Wallet  with  a Hole  in it

Leaks translate into cold cash.  Allowing leaks to exist without a leak identification and  repair program  will add  a hidden cost to the products your company produces which can  negatively impact the ability of the company to compete and  affect profitability.

Many times, we liken these leaks to having small pinholes in your automobile gas tank.   After a while, you’ll notice how they’ve created a hole in your wallet.   The time to stop them  is now.  Energy  is not going to get less expensive.

If you are  employee in plant where  leaks are  not addressed, safety and  your environment can  be an unintended consequence.  There  are  many  potentially explosive gases such as hydrogen and  natural gas that can  leak.  In addition, there  are gas leaks that can  also impact the environment, such as the “greenhouse gases”.

Did you  know that something as apparently innocuous as compressed air leaks can have environmental consequences?
Is an  Air/Gas Leak  Audit  Cost Effective Even in a Smaller Plant? Yes.

Leak detection is important in any size plant.   In a smaller plant your financial survival and  competitiveness are  that much more  important.

For larger plants, the impact may be exponentially more  costly. W hen  we perform an audit in a large plant, we typically find between five and  ten thousand or more  dollars per day of loss through  leakage. Once  you get a handle on your leaks, it’s not unusual to be capable of shutting down the operation of an extra  compressor.

How often should a leak audit be performed?   Most of our customers want the audit done  semi-annually or at least once  a year.

Enlist the help of Department Employees

  • When  leaks become large enough they become audible without the need for ultrasonic scanning.
  • Heighten the awareness of all individuals in each department. Ask them  to report  leaks that may be audible.
  • If you do not already perform ultrasonic leak detection, consider contracting a Leak detection provider to work with each of your departments to perform an initial leak audit.
  • These air/gas leak auditors should be recognized as “energy conservation champions”.  As energy continues to become extraordinarily expense we must take  steps to conserve.  Our very manufacturing existence might depend on it.   It is that important.

Experience and Proper Equipment Matters

I was taught  that in some cases you can  get by with less.   However,  to do the best job, sometimes you need the best.  A contractor who has the best equipment makes your job easier and  you ultimately save time.   As they say time is money.   In the end, you will thank  yourself for using reliable instrument and  top trained technicians.

Professionals, keep  their equipment properly calibrated and  take  all steps to maintain the instrumentation.

Performing a leak  survey

The success of a leak survey requires three  major elements:

  1. Knowledge
  2. Planning
  3. and follow-through.

The knowledge component includes an understanding of the compressed air system, including all the subsystems and components.  W hat are  the sizes, types and  ages of the compressors?  Have  they been properly maintained?  W hat about  your traps and  drains?   Are your pressure gauges working and  if so is there  adequate pressure for the various areas of use? W hat are the assigned pressures for these areas? Are there  compressed air applications that can  be replaced by alternative, less energy intensive methods?  For example, instead of using compressed air for cooling, drying or cleanup, try using low=pressure blowers or fans.

Knowledge can  also include the understanding of your ultrasound instrument, how it works and  the techniques of inspection.  If you are  not too sure about  the technology or how to use the instrument, use trained Leak Detection providers whose technicians have  attended to proper  training courses available that can  help make  you and  other  inspectors in your facility more competent and  effective in your inspections.

Planning incorporates a number  of facets such as a map  of the compressed gas system and  its various components.  If none  exists, try taking digital photographs of each section using long range and  close-up views and  labeling them.   Planning also includes scheduling of the survey.  Don’t try to do it all at once.   Break  it up so that the survey can  be performed without negatively affecting other  maintenance responsibilities of the personnel assigned the leak team.

Before the survey begins, have  the inspectors walk through  the various sections to review their route.   The walk-through can  help in a number  of ways: it can  help identify potential safety issues, note  any changes needed to the planned route,  identify obvious leaks, and  help understand what equipment to bring along such as flashlights, keys, or specialized leak inspection attachments.

Another  component to planning includes a leak tag/identification method.  Once  a leak has been located, it should be tagged.  The tag number  can  be used, along with a photograph of the leak in your report.   The identification process is extremely important.   The leak rate  can  be assigned to the leak in a report  that can  then  be used to demonstrate the cost savings and potential environmental impact of the leak.   In addition, the leak identification process can  be used to be sure a leak is repaired.  It is very costly to leave an identified leak un-repaired.   Money is wasted due  to the cost of the personnel used to locate the leak.  In addition, the cost of the leak will increase for every  second it continues without repair. The top end  Ultrasonic equipment incorporate digital camera capabilities and  touch  screen label inputs to make  the tag and  identify process easier.

Follow through is another important factor.  If a leak is not repaired, as mentioned, all the effort and  cost of the survey

will be  wasted.  Therefore, it is important to use a “follow-up” method to assure all identified leaks are  repaired.  In addition, when  a leak has been reported as fixed, the repair should be checked.  Sometimes the repair might cause another leak to manifest or the wrong component is “repaired”.  Follow-through includes review of the survey, cost analysis and,  when  possible, environmental impact analysis.   A report  can  then  be generated to demonstrate the effectiveness of the survey and  the related cost savings benefits.

Follow through includes “leak management”.  Whenever a survey is complete there  are  often many  identified leaks.  The problem is the sheer volume of these leaks can  seem overwhelming to a maintenance department that is already working hard  at meeting the daily maintenance requirements they are  normally assigned.  It is important to work a system that will allow for the leaks to be repaired.

One  method is to prioritize the leak repair so that the costliest leak or leaks that can  affect production are  repaired first, the next most important later, and  so on.

Some Leak Detection providers also offer leak repair services and  can  help you prepare detection and  repair plans for your management, that will simply pay for themselves in energy savings realized and  give you additional thumbs up from your environmental department in reduce carbon footprint.

Record keeping is another important element to the follow through  part of a survey.  Some companies provide software that can help.   One  such program  is “freeware” used by Innovator It is a two-stage software that combines data  management and comprehensive compressed gas survey analysis.   Users can  review annualized and  monthly data  that includes leak cost and greenhouse gas savings.

Conclusion

Compressed gases can  be costly in more  than  the obvious. The cost of producing or purchasing the gas is one  factor.  Safety, the environment, and equipment degradation caused by leaks and  equipment inefficiencies can  all add  up in many ways that can impact on a company’s ability to compete and  maintain profitability.  A planned, comprehensive leak survey program  can  provide savings that can  improve plant-wide productivity and  profitability.