Difference Between a Compressor & Booster

SCFM Vs. ACFM

Question: What do we need to understand differences between SCFM, ACFM and ICFM measures of flow and what is needed to provide a solution?

Answer: Volumetric flow measurements can be confusing and some equipment manufacturers tend to be a little vague in order to reflect positively on the performance of their equipment. The first reason for the confusion is the simple fact that gases are compressible. As such, variations in pressure, temperature, and humidity significantly change the volume and density properties of the gas. Additionally there are many variations in the “standard” definitions for the different flow rate measurements. It can all seem pretty confusing.

Standard Cubic Feet per Minute (SCFM) is used as a common reference for flow rate performance. However, there are at least 13 recognized variations to the “standard” conditions, published by agencies like CAGI, NIST, ANSI, ISO, EPA, U.S. Army, etc. At Hycomp, we primarily use the standard conditions of Pressure (14.696 psia) and , Temperature (60 F). SCFM is used mostly as a common reference point for comparing the performance of different pieces of equipment.

Actual Cubic Feet per Minute (ACFM) is used to express the volumetric flow based on defined pressure and temperature conditions at the location in the system where the measurement is being taken. ACFM could reflect the flow at the inlet to a compressor. ACFM could reflect the flow at the discharge of an air booster. ACFM could reflect the flow at the point of use of plastic bottle blowing equipment. It all depends on what is defined. It is important not to confuse ACFM with atmospheric conditions at the site, although since this could be part of the “system”, ACFM and atmospheric conditions could be same.

Inlet Cubic Feet per Minute (ICFM) is used to express the volumetric flow based on the actual pressure and temperature conditions at the inlet to the equipment. ICFM and ACFM at inlet conditions are, of course, identical. Sometimes ICFM is used interchangeably with the term Free Air Delivery (FAD).

The generic term, Cubic Feet per Minute (CFM), is used at times by manufacturers, but it is inherently misleading since it is not tied to any frame of reference.

With all of these units of measure, the most critical step to understanding them well is to be sure that the definitions and the standard conditions being referenced by all equipment manufacturers and users are matching up with each other. Without that, you are literally comparing apples to bananas. There are plenty of resources on the internet that can help with definitions of standards and making conversion calculations so that the comparisons are valid. Proper understanding and use of common definitions will certainly help eliminate confusion.

A few general rules to apply are:
1. Spend some time with equipment providers and equipment users to be sure that everyone is using the same standard definitions.
2. In general, use SCFM to compare equipment capacities
3. In general, use ACFM to make calculations regarding actual conditions and equipment loading.
4. Always consider the worst case site and/or system conditions as part of the calculations.
5. Call Hycomp and arrange an E2E discussion to sort it all out.

Mike Byrd of Air Services Company recently had a complex booster application for PET plastic bottle blowing that he was working on with his customer. The system involved multiple equipment providers. The customer was having trouble getting clear information regarding flow requirements and specifications. During an Engineering to Engineer (E2E) discussion with the end user, all the parties were able to clarify the flow measurement information by settling on the same standard definitions as a common baseline. A consensus was reached quickly and the right solution was proposed.

After that E2E discussion, Mike reported back to Hycomp:

”I just want to let you know how well the E2E conversation we had last week went. Shortly after our conversation ended, I received a phone call from my customer thanking me for taking the time to speak with them. Their high level management personnel all had questions that they needed answered so they could make a more educated decision on their equipment purchase.”

Mike concluded, “By the end of the conversation we all had a much better understanding of compressed air boosters, flow ratings, the customer’s process and the Hycomp solution. I am confident that this conversation “boosted” our odds at getting an order and gave the customer more confidence in the Hycomp product. Thanks for your help.”

Mike was right, 7 days later, the customer issued a purchase order for a Hycomp Oil Free Air Booster.

Gas Compression: Safe & Reliable

Hycomp engineers truly understand gas compression, and more importantly, we know how to engineer gas compressors and boosters that are both safe and reliable.

In 1979 we were chosen to manufacture four units for the Susquehanna Nuclear Power Station. Because of the nuclear incident at Three Mile Island, this was an extremely sensible decision. Pennsylvania Power and Light was very selective and discriminating in its search for a company to provide reliable nitrogen containment compressors. Characteristically, those compressors we provided 34 years ago are still in operation today.

Manufacturing safe and reliable compressors is a job we take very seriously. When compressing gas there are 3 main concerns: Containment, Control, and Contamination.

Containment

No matter what gas is being compressed, from inert gases to hazardous gases, containment is paramount. Gas containment is usually an issue of keeping gas from escaping the compressor to the atmosphere and possibly hazardous surroundings, but it can also be an issue of external gases (i.e., air) contaminating the gas being compressed.

Design

Every gas compressor Hycomp builds is designed, engineered, and manufactured to provide containment you can trust. We utilize 3 levels of containment with our gas packing configurations. In all 3 containment options, the suction gas is plumbed through the plenum chamber, equalizing pressure on, and providing cooling to the pistons and piston rings while rendering balanced piston rod loads.

• The B-Series compressor is designed to compress air or nonhazardous gases.
• The G-Series compressor is designed to compress standard industrial gases.
• The H-Series compressor is designed to compress difficult-to-contain industrial gases.

Control

Hycomp engineers know how to control the factors involved in gas compression. These main factors are: Components (primarily: Rings & Gas Packings), Environment and packaging. Within each of the three gas packing configurations, we offer there are also gas-specific containment features. Hycomp matches the gas to the piston ring and gas packing materials to ensure that the gas or gas mixture is fully contained and/or protected from external contamination.

Components

Hycomp quality means attention to detail. By holding our materials and production methods to a higher standard, we provide you with industrial-duty compressors that outlast and outperform the competition. We match the controls and packaging to our compressor quality and tailor the whole system for your application. Hycomp simply means quality & longevity. For example, our pressure lubricated crankcase allows for 24-a-day operation for nearly 5 years before the main bearings will need to be changed out.

Rings

The proper selection of a piston ring material and design will add years of reliable service to your gas compressor. We stock seven different polymer based piston ring materials to meet today’s varying gas demands. From PTFE to PEEK and PPS, we can provide the right ring material for your application.

Our angle cut design allows for flexing of the ring end to seal the gap better than butt cut designs, yet retains its strength vs. step cut designs. In situations where gap leakage becomes significant, such as low molecular weight gases and small cylinder bores, we use a 2-piece ‘L’ style design that removes the end gap by using an inner and outer ring for sealing.

Gas Packings

Piston rod gas packings perform the critical function of containing the gas in the compressor while providing pressure on the underside of the pistons to balance the rod loads. Our tangentially cut segmented packings are free floating and self-adjusting for long wear life. The design inherently continues to seal as the packing wears. Gas packings are pinned together in pairs at the proper rotational offset to ensure that the leak path created by the cuts is sealed.

Just like our piston rings, we stock seven different packing materials to meet your needs. And unlike chevron-type packings, our segmented packings do not need constant adjustment to ensure a tight seal.

Environment

The surrounding environment is a very important factor when considering compressor packaging. For example, if nitrogen, or any nonflammable gas, is being compressed in an environment where an explosive media is always present, then the compressor and packaging must be packaged to the proper explosion-proof ratings. Conversely, any time an explosive or flammable gas is being compressed, that compressor system must be “explosion proof.”

Packaging

Safety is, once again, of the highest importance for items such as control panels, motors, and VFDs. Whether UL, IEC, ATEX / CE, or other rating systems, Hycomp works with the distributor and end-user to understand what is needed.

Hycomp offers NEMA 7 control panel enclosures to ensure that the electric components inside the control panel are isolated from any dangerous gases. Manufacturing a safe compressor system goes further than just the control panel. All electric and mechanical equipment must also be packaged or enclosed correctly to protect against accidental explosions.

Hycomp has the experience and engineering expertise to handle the packaging and enclosures that your application requires. Our engineers get involved from the outset to provide the proper system packaging for the rating system of your region.

Contamination

Everything Hycomp manufactures is oil-free. Our design incorporates the strengths of the oil-less and oil-flooded reciprocating compressors and none of their weaknesses. To accomplish this, our compressors are both oil-lubricated and oil-free. However, the oil used to lubricate the crankcase never enters compression. CLICK HERE for more information on how Hycomp gas compressors provide all the strengths of oil-less and oil-flooded compressors without any of their weaknesses.

Hycomp safety does not only protect against gas leakage, we also protect your system and end product. Every Hycomp compressor is oil-free. Therefore, your system remains oil-free and your product is kept safe from oil contamination.

Gas compression may appear dangerous and truth be told it truly can be, however, you can trust Hycomp to manufacture a safe compression system that is built to the specifications you application requires. We are compression experts and we have come to understand that gas compression is not something to be feared, it is to be respected. That is why we make sure to investigate the intended application and gas mixture during the quotation phase of the sales process. We want your personnel and property to be kept safe.

If you have never worked with Hycomp concerning gas compressors, call us when you are compressing any gas other than air and we will show you The Hycomp Difference. We will demonstrate that you can trust Hycomp and that you can trust our experience and engineering. Trust… it’s what we build.

Redundancy is The Answer

Redundancy is a big word in business; it can be a great word or a bad word. If you have it, it’s a really good word. If you don’t, it’s a bad reminder of when you should’ve had it.

Recently at Hycomp Inc. we lost our internet and phone services for nearly an entire day due to a cut fiber optic cable over 500 miles away. This misfortune disconnected our ability to communicate with the outside world via phone and email—vital elements in the day-to-day operations of our company. This communication downtime put us behind on several issues; for those that were affected, we apologize.

Not wanting to repeat this ordeal, we are installing a backup internet connection via a completely different service, that will guarantee us the ability to operate in our usual productive manner if our primary connection ever fails again. We will be able to communicate to those who matter most to our business, namely our customers. We are securing our ability to operate and remain online through the protection of redundancy.

Downtime can be a detriment to any company, from not being able to communicate with clients to completely disabling production. PET blow molded packaging, nitrogen-assisted metal laser cutting, air starting diesel engines, or vapor recovery in the oil & gas industry—no application is exempt from the harm of downtime. That is, unless they are protected by redundant systems.

When it comes to reciprocating equipment like Hycomp compressors, even when a company follows preventative maintenance schedules to the letter, there are still unforeseen incidences that can cause a compressor to be offline for a time. With a second compressor readily available, customers can instantly switch to the secondary compressor, allowing the primary compressor to be maintained while the system is still up and running, resulting in zero downtime.
For example, an international pharmaceutical manufacturing company is currently building a new facility in Central America. Downtime is so expensive (over $200,000 a day) for their manufacturing process that they purchased a pair of duplex Hycomp air booster systems that provide full redundancy. Although the entire system cost more on the front end of the project when compared to the cost of downtime and its accompanying stress, a redundant system will end up costing them less in the long run, and they consider it an inexpensive insurance policy. Just like Hycomp and our backup phone and internet system, we hope end-users will enjoy the benefit of a simple solution: redundancy. Redundancy offers the benefit of peace of mind to any company, knowing they will always avoid costly downtime while continuing to experience peak performance.

Reciprocating: Pulsation Dampening Paramount

When purchasing capital equipment it is wise to protect that investment through proper packaging and installation. Inlet and discharge receiver tanks are often overlooked, but make all the difference in protecting a compression system and providing consistent pressure to any air/ gas boosting application.

Reciprocating compressors create pulses in the gas stream. This pulsation is inherent to reciprocating motion. To accommodate this force, a proper system design and installation must be utilized to prevent failure and promote peak performance.

Think of driving a car with square wheels, each forward rotation of those wheels would create a jump forward followed by a thud and an abrupt halt in motion. Gas flow enters the piston only during the suction portion of the compressor stroke and leaves only during the discharge portion. The flow is effectively stopped on first the inlet and then the outlet of the reciprocating piston. In a compressor running at 600 rpm, this can happen as often as 10 times a second. Compression creates pressure waves, or pulsations, that travel through the system. These pulsations occur in both directions and combine to create very high-pressure fluctuations.

Piping systems are seldom designed to handle pulsation created by reciprocating compressors, especially at fittings or components. If pulsation is not controlled, components and compressors can experience many different failures, such as: pipe failure due to fatigue, reduction in efficiency of the compressor, ‘hammering’ of the compressor valves, check valve and safety valve failure, instrumentation failure, and even errors in pressure measurement.

Receiver tanks act as buffers to the inlet and discharge of the compressor. Pressure waves are dissipated inside the tanks which provide increased system longevity while creating a consistent and reliable process pressure. To ensure properly sized receiver tanks are packaged with your air or gas booster compressor system, contact Hycomp for more information.

Pressure Drop

There is nothing worse than making it through a technical project only to be disrupted by some critical detail that was overlooked. Pressure drop is often overlooked, misunderstood and misdiagnosed.

Pressure drop is often the cause of excessive energy consumption and poor system performance. If unaddressed before the purchase of a compressor or booster, you could be buying an improperly sized unit. If unaddressed or misdiagnosed for an existing system, it can lead to costly downtime, unexpected and even unnecessary equipment expenses.

Pressure drop is a term used to characterize the reduction in air or gas pressure anywhere in a compression system. A properly operating system should be designed with the least amount of pressure drop that is practical. For example, it is not practical to have long runs of undersized piping, but properly sized check valves are necessary and the pressure drop associated must be taken into account.

Imagine a freeway in a large metropolitan area that has only one or two lanes, onramps that bottleneck, and numerous sharp turns. Traffic becomes congested and motorists have to slow down when using the onramps and navigating the sharp turns. Compressed air and gas systems experiencing pressure drop issues are similar to an undersized and poorly designed freeway. In this example the freeway represents the pipe sizing and arrangement, the onramps represent ancillary equipment such as filters, dryers, and gas separation equipment while the sharp turns represent components such as valves, fittings, and junctions.

What Causes Pressure Drop?

Any type of obstruction, restriction, or roughness in the system will cause resistance to gas flow and cause a pressure drop. In a distribution system, the highest pressure drops are usually found at the points of use, including undersized or leaking hoses, tubes, disconnects, filters, and regulators. On the supply side of the system, aftercoolers, moisture separators, dryers, filters, and improperly sized piping are the main items causing significant pressure drops.

The maximum pressure drop from the supply side to the points of use will occur where the compressed air flow rate and temperature are the highest. System components should be selected based on these conditions and the manufacturer of each component should be requested to supply pressure drop information under these conditions. During the design phase, it is critical that occasional large flow requirements (air bursts, startup/shutdown of equipment, etc) are recognized, and the system is designed to handle the pressure drops for these occasional large flows. This is exactly why, during the quoting and compressor sizing process, Hycomp salesmen and engineers work with our customers to completely and accurately fill out the Hycomp Application Worksheet (“Application Worksheet” will be a link to our AppWork form).

The distribution piping system often is diagnosed as having a high-pressure drop because a point-of-use pressure regulator cannot sustain the required downstream pressure. If such a regulator is set at 85 psig and the regulator and/or the upstream filter has a pressure drop of 20 psi, the system upstream of the filter and regulator would have to maintain at least 105 psig. The 20 psi pressure drop may be blamed on the system piping rather than on the components at fault. The correct diagnosis requires pressure measurements at different points in the system to identify the component(s) causing the high-pressure drop. In this example, the filter/regulator size would need to be increased, not the piping.

Minimizing Pressure Drop

Keeping pressure drop to a practical minimum requires a total systems approach in design and maintenance. Air treatment components, such as aftercoolers, moisture separators, dryers, and filters, should be selected with an acceptable pressure drop at specified maximum operating conditions. When installed, the recommended maintenance procedures should be followed and documented.

Additional ways to minimize pressure drop are:

• Properly design the distribution system.
• Operate and maintain air filtering and drying equipment to reduce the effects of moisture, such as pipe corrosion.
• Select aftercoolers, separators, dryers, and filters having the least possible pressure drop for the rated conditions.
• Reduce the distance the air travels through the distribution system. If long runs are required, properly size the pipe.
• Use new, smooth bore, clean piping.
• Specify pressure regulators, hoses, and connections having the best performance characteristics at the lowest pressure differential.

Hycomp Investigation & Experience

When Hycomp compressors and boosters are configured and sold, they are sized to accept a specific inlet pressure and flow. If the pressure drop of all the other installed components before the Hycomp booster is not taken into account, for example, what was thought to be 120 psig at inlet could be more like 100 psig, then the booster may not be able to achieve the desired discharge pressure. Even if the compressor works harder to provide that pressure and succeeds, flow and/or reliability may suffer.

One thing that may be blamed for pressure drop is actually pressure loss. This can occur when process demands exceed the supply capabilities. If an application requires a specific flow and then that requirement is increased, chances are that the booster may not be able to provide the increased demand. For example, an end-user runs a laser-cutting facility and purchased a Hycomp nitrogen booster that mates with their N2 generator to provide 3 laser-cutting machines with 600 psig at 45 scfm flow each. If the end-user then installs 2 more laser cutting units without upgrading their nitrogen boosting setup, they could be disappointed in the results as the single booster may not be able to handle the increased demand (pressure and flow) at the point of use.

Hycomp sales professionals and engineers have the knowledge to assist distributors and end-users in properly sizing a compression system to fit the desired application. This begins with a thorough investigation on the front end of an inquiry and continues until the compressor system arrives on location and is in operation. However, if precise conditions are not given and system pressure drops are not accounted for, a perfectly operating and brand-new compressor or booster system may not be able to meet the requirements. So much is riding on the original info that is collected using a Hycomp Application Worksheet; it is paramount this information be accurate.

Much like a cross-country road trip, if you fail to properly plan your route, you could find yourself far from your intended destination. All the information collected for sizing a compressor must be accurate or you could find yourself in a situation where the compressor just purchased can’t keep your application in operation. Trust your Hycomp sales and engineering team to help you plan and investigate each application, so your process always runs efficiently.

Nitrogen

Description:

Nitrogen (N2) is a colorless, odorless, and tasteless gas that constitutes 78.08% of the volume of the air we breathe. Nitrogen is an inert gas; the term inert basically means unreactive.

Nitrogen occurs in all living organisms. Nitrogen is a constituent element of amino acids and thus of proteins and nucleic acids (DNA and RNA). It resides in the chemical structure of almost all neurotransmitters, or in other words, nitrogen is an important chemical in the thinking process, and as you read this article you are utilizing nitrogen to connect cognitive thought patterns via synapses in your brain.

The bulk of nitrogen produced in the United States is done via cryogenic separation of air. Air is supercooled to a liquid state, and the different gases stratify, just as water and oil do in a glass. Nitrogen is then pulled out as a liquid. Air separation plants can be large facilities serving multiple customers usually covering several states, or site-specific for large users of nitrogen. Cryogenic nitrogen purity can vary depending upon need but can hold in the ppb (parts per billion) of contaminant gases.

A method of Nitrogen production gaining rapid favor for its ease of installation and relatively low cost is nitrogen generators that separate the nitrogen from the air in the gaseous phase, either through the use of a membrane or via pressure swing adsorption (similar to regenerative air dryers). These units are fairly small in size and production volumes (roughly 100-10,000 scfh per system) but can be 1/10th to 1/100th the cost of a cryogenic separation plant. However, gaseous nitrogen generators don’t produce pure nitrogen – they actually remove oxygen. So while the oxygen content can reach less than 10ppm, there will still be other gases present in the nitrogen that are also present in the air – gases like argon, helium, carbon dioxide, etc. In many applications, this is acceptable, as nitrogen is being used because oxygen cannot be present in the process.

Safety, Storage & Handling:

Nitrogen is commonly stored in high-pressure cylinders, tubes, or tube trailers. Liquid nitrogen is commonly stored at the consumer site in cryogenic liquid cylinders and specifically designed vacuum-insulated storage tanks. All of the precautions necessary for the handling of any nonflammable gas or cryogenic liquid must be taken.

If levels of nitrogen become too high in confined spaces it can cause asphyxiation, leading to unconsciousness or death. Therefore, all nitrogen compression equipment must be located in a well-ventilated area. We urge you to review local and regional safety standards to ensure safety compliance.

To dispose of nitrogen gas, vent the N2 slowly to a well-ventilated outdoor location remote from personal work areas and building air intakes. For liquid nitrogen, allowing it to evaporate in a similar location. Liquid nitrogen boils at -320oF, so any temperature above that will be sufficient.

Uses:

Nitrogen has many commercial and technical applications. As a gas, it is used in heat treating of primary metals; blanketing of oxygen-sensitive liquids and of volatile liquid chemicals; the production of semiconductor electronic components, as a blanketing atmosphere; the blowing of foam-type plastics; the deaeration of oxygen-sensitive liquids; the degassing of nonferrous metals; food processing and packing; inhibition of aerobic bacteria growth; magnesium reduction of aluminum scrap; and the propulsion of liquids through pipelines.

Gaseous nitrogen is also used in pressurizing aircraft tires and emergency bottles to operate landing gear; purging, in the brazing of copper tubing for air- conditioning and refrigeration systems; the purging and filling of electronic devices; the purging, filling, and testing of high-voltage compression cables; the purging and testing of pipelines and related instruments; and the treatment of alkyd resins in the paint industry.

Liquid nitrogen also has a great many uses, among them the freezing of highly perishable foods such as shrimp, hamburgers, and chicken; deflashing of rubber tires; cooling of concrete; and the cold-trapping of materials such as carbon dioxide from gas streams (commonly used in this way in systems that produce high vacuums). It is used as a coolant for electronic equipment, for pulverizing plastics, and for simulating the conditions of outer space. Other ways in which liquid nitrogen is used include: creating a very high-pressure gaseous nitrogen (15,000 psig or 103,000 kPa) through liquid nitrogen pumping; in food and chemical pulverization; for the freezing of liquids in pipelines for emergency repairs; for low-temperature stabilization and hardening of metals; for low-temperature research; for low-temperature stress relieving of aluminum alloys; for the preservation of whole blood, livestock sperm, and other biological; for refrigerating foods in local and long-distance hauling; for refrigeration shielding of liquid hydrogen, helium, and neon; for the removal of skin blemishes in dermatology; and for shrink fitting of metal parts.

Liquid nitrogen also has a number of classified applications in missile and space programs, in which it is used in large quantities.

Gas Packings: Chevron Tangent-Tangent

Piston rod gas packings perform the critical function of containing gas in the compression end of a compressor. The two most widely used gas packing design styles are Chevron and Tangent-Tangent. There are pros and cons to both designs. However, Hycomp employs the Tangent- Tangent packing style due to quality and efficiency. The following article will explain why.

Chevron Gas Packings (V-Packings):

Chevron gas packings are also referred to as V-Packings or Vee-Packings due to their shape when viewing them as a cross-section. The chevron packing arrangement is a combination of three main sections: the Base Seal (bottom), the “V-Rings” at the center, and the Pressure Ring (Top). The V-Rings provide the main seal that while the base seal supports the center rings from getting extruded during high-pressure applications and the Pressure Ring helps hold it all together while providing a method of adjustment. Pressure is applied to the V-Packings by both the Pressure Ring and the Base Seal, causing the V- Packings inside to widen or squish and provide the seal (see illustration). As the packings wear, the seals loosen and the Base Seal and Pressure Ring must then be re-tightened.

The main problem of this design is the constant adjustment necessary to keep a tight working seal as the packings wear. Depending on the intervals of use, the need for re-adjustment can occur frequently. Monitoring the performance of the compressor combined with the constant need for adjustment leads to higher costs and decreased efficiency in the long run.

Tangent-Tangent Gas Packings:

Tangent-Tangent Gas Packings (TT Packings) provide a dynamic seal that does not require constant monitoring and continuous tightening. This packing style is self-adjusting and therefore provides a tighter and more efficient seal throughout the entire life of the packing.

Tangentially cut, this segmented packing design provides a dynamic seal by lining up and sandwiching each set of packings via a white pin for alignment at the proper rotational offset to ensure that the leak path created by the cuts is minimized (see illustration). The Tangent-Tangent (TT) style packing inherently continues to seal as the packing wears due to the tangentially cut design, dynamic pressure, and a small spring that helps hold the pieces together inside the packing gland.

TT Packing arrangements can be configured to provide even more stringent containment by increasing the number of packing pairs, incorporating purge/vent lines, or by utilizing an additional plenum chamber filled with a pad gas. Hycomp compressors can be designed and engineered using all three methods of containment when gases are either very dangerous or contain very small molecules or both.

When increased gas containment is necessary another set of gas packings is added and purging gas lines are used to carry away any gas that has entered the purge chamber between the bottom two sets of gas packings (see “G-Series” illustration). For applications that require extreme containment, purge lines are employed along with an additional plenum chamber. The second plenum chamber is pressurized with an inert pad gas to provide opposing force and to ensure process gas purity (see “H-Series” illustration).

The end result of using Tangent-Tangent Gas Packings is a reliable and consistent seal. Chevron gas packings are less expensive as an initial purchase but require continuous monitoring and constant re-adjustment, which leads to an overall higher cost and increased hassle. Tangent-Tangent packings are far more user-friendly as they are self-adjusting and do not require constant monitoring or maintenance.

Foundation Installation

Question:

How do I properly mount a compressor to a new foundation or an existing one?

Answer:

Proper installation has a direct relationship with the operation and longevity of a compressor. When an installation is done right, the compressor is mounted to a secure foundation to minimize vibration and ensure correct operation.

When the installation is performed incorrectly the compressor may experience operational problems that can lead to significant maintenance issues and unwanted downtime. The three most important factors when building a foundation for your Hycomp compressor are: Location, Foundation Construction, and Pre Installation Technical Advice.

Location:

Many factors must be considered for optimal compressor location. Locate the compressor in a dry, well-ventilated, and well-lit area that accommodates inspection and maintenance access. An unobstructed machine boundary of at least 18” must be arranged to provide adequate airflow and service space around the compressor.

Installation in locations exposed to ambient subfreezing temperatures is not recommended. Exposure to direct sunlight, rain, wind, dust, snow, moisture, and other adverse environmental elements is not recommended and will reduce service life and increase maintenance requirements. If it is necessary to install the unit out of doors, provide a rain cover or a completely enclosed shed to prevent corrosion. If the installation location will experience operating temperatures below 32°F, a properly sized crankcase heater must be installed.

Rotating machinery should always display appropriate restrictive warnings and cautions to minimize the risk of injury to personnel. Even though Hycomp compressors are not as loud as other pumps, rotating machinery does produce noise. Understand your service environment and prepare accordingly.

Foundation Construction:

Proper foundation construction ensures smooth operation, reduces vibration, and can extend the life of your compressor. Todd McGregor, Hycomp Service Manager, has performed many factory startups and seen differing levels of installation quality. He explains a few things to look for when building on an existing foundation, “For installation on an existing floor – Check the floor plan and establish how the floor was constructed, for example: concrete aggregate/psi, how thick is the floor, how well was the floor reinforced and how old is the foundation. Based on these facts – get expert advice for what will work best for your situation.”

Robert James, Hycomp President and Engineering Manager, understands that a new foundation may not always be possible, “In existing floors, a “Drillco Maxi-Bolt” is a good choice, as it actually utilizes a special undercut hole which allows the anchoring to be rock solid.”

When building a new foundation it is important to not cut corners and utilize the following parameters. The foundation should rest on solid bedrock or compacted earth or gravel, but not a combination of the two. The pad should be composed of 4,000 psi cured concrete reinforced with ASTM A615 #4 billet steel re-bar cross laced on 16” centers located 3” above the base. The amount of concrete used to form the pad should exceed the weight of the compressor by 3 to 5 times. SAE Grade 5 “J” bolting of appropriate length and size should be used in the pad to provide baseplate mounting. Use of a template to support and position the bolting +/– 1/16” while setting concrete is recommended.

Securing bolting to existing foundations with drilled holes and adhesives is not recommended unless expert advice is available. Expert advice is also recommended for the installation of other forms of mechanical anchors. Call Hycomp if you are unsure what size to use or for technical advice on different anchors. McGregor instructs further on compressor mounting and shimming, “Installers need to utilize all skid mounting holes intended for anchoring. Compressors must be level. Use shims as needed. Shimming of skids (on concrete and steel foundations) may be required to prevent excessive vibration. Steel fabricated foundations must be adequately engineered to support the weight and vibration of the compressor.”

Epoxy-based grouting is required to firmly seat and attach the compressor skid to the concrete foundation for newly constructed or existing foundations. ITW Philadelphia Resins brand “Chockfast Red” grout is recommended. “I think there are a few general pieces of advice that should be considered for grouting of fabricated channel skids, such as: do not fill it up to the point that one cannot access the compressor or motor mount bolting, drill for drain holes if located out of doors, plumb oil drain to skid edge, etc.,” said McGregor.

Sealing of grouts and concrete is recommended to prevent contamination by oil and moisture. The concrete slab should be chipped to expose 50% of the aggregate and to provide a rough bonding surface for the epoxy. Dowels should be installed on new exposed concrete to prevent edge lifting. The concrete foundation should be dry and free of oil before pouring grout. Sleeve all foundation bolts to prevent adhesion and allow bolt stretch. Steel baseplates should be sanded and cleaned to provide an adequate adhesion surface.

Pre Installation Technical Advice:

Unlimited tech advice and support are included at no additional charge with every Hycomp compressor. Hycomp technicians are available to assist you 24 hours a day. Hycomp technicians like Todd McGregor are ready to answer your questions, “Our customers can call 24 hours a day, 7 days a week, and 365 days a year. We will do our best to get them the answers they need so their Hycomp equipment is operating in a correct manner.”

Proper Filtration First Priority

You wouldn’t run your car without an air filter, so you certainly wouldn’t want to operate a compressor without proper filtration. Sounds simple enough, but some important precautions concerning filtration often go overlooked.

The number one problem with new installations of air and gas boosters is debris from the piping system damaging the new compressor. Hycomp service technicians have found weld slag, mill scale, Teflon tape, pipe dope, filter element fibers, rust, and even carbon dust contaminating newly installed air boosters and gas compressors.

This debris can become embedded in the polymer piston rings, causing scoring of the cylinder wall, or get lodged in the valves, causing valve damage and valve leakage. Perhaps the worst case was an air booster attached to 1,000 ft. of old, underground iron pipe. The owner started the air booster for the first time, went to lunch, and upon return found the connecting rod had punched out the side of the crosshead cylinder because the compressor had literally filled with rust particles and other debris, seizing the entire compression end.

When installing a Hycomp air or gas booster into your system, setup is not complicated. But if the proper installation method is not followed, it can lead to a variety of problems. Simply put, the inlet air/gas absolutely must be filtered. However, due to the pulsations caused by a reciprocating compressor, it is not acceptable to simply put a filter directly in front of the Hycomp booster. The pulsing air/ gas can tear the filter element apart, causing it to be sucked into the booster, leading to the same damage the filter was designed to prevent.

The solution is to place a receiver directly upstream of the booster compressor, with a properly sized filter at the inlet of the receiver. In addition to providing a local capacitance for the booster, the receiver acts as a pulsation dampener to prevent damage to the inlet filter. It then becomes a question of sizing the filter properly, and ensuring the receiver and piping from the receiver to the booster, are clean of debris.

The inlet filter should be rated at one (1) micron to remove any contaminant introduced by the original plant piping. To properly size the inlet filter, remember that the booster doesn’t flow smoothly, but takes in gasps – at 600 RPM, an air booster takes gasps of air 10 times per second. Since filter elements are rated for smooth continuous flow, and the inlet stream to the compressor is pulsing, consideration must be made to accommodate the difference. Hycomp recommends sizing the inlet filter for twice the nominal flow of the booster, to ensure pressure drop is minimized and damage to the filter element does not occur. Install the filter directly at the inlet to the receiver.

Next, the inlet receiver must be clean of any foreign contaminants. During manufacturing, air and gas receivers are welded, hydro-tested, and then shipped to the customer, leaving mill scale, slag, rust, water, and oil inside the ‘new’ receiver. This must be removed, or the debris from the ‘new’ inlet receiver will cause problems. Hycomp recommends getting the receiver epoxy lined (when compatible with the gas stream), to ensure the interior is clean and free of debris. The receiver should not restrict the gas flow, so for larger systems, it is often necessary to use a larger receiver. Contact Hycomp for assistance in sizing a standard receiver.

Finally, the piping from the inlet receiver to the booster compressor must be cleaned. Hycomp service technicians have found newly installed piping filled with weld slag, mill scale, Teflon tape, and pipe dope. Hycomp strongly recommends against the use of pipe dope, as it is often applied too liberally, causing excessive dope to be pushed inside the pipe during the assembly process.

Teflon tape with a proper sealant such as a few drops of Loctite 545, is an excellent method of sealing pipe threads. Just remember that the tape should be placed at least one full thread back, to ensure no tape can make its way into the pipe during assembly – and at no time should the Teflon tape overhang the end of the thread. If the pipe is welded or soldered, cleaning before welding/soldering, and especially after, will prevent oxidized particulates from breaking free during operation and entering the booster.

Remember these key points during installation:

• Install the inlet filter directly at the inlet to the receiver, sized for twice the nominal flow, and rated at one (1) micron.
• Use a clean or epoxy-lined receiver.
• Keep the piping between the receiver and the booster as short as possible to prevent unwanted pressure drops. Plus, short piping means less chance of debris.
• Use a flexible metal hose at the booster inlet to isolate vibration.

Hycomp can supply a packaged air/gas booster compressor with inlet filtration and a receiver pre-assembled and either installed on the skid or shipped loose for local installation. As this is not complicated, we certainly don’t require that a pre-assembled inlet setup is purchased from us. We do, however, require that no debris enter the booster compressor, and this method of installation has proven to be very successful at allowing smooth, worry-free startup and operation.