- Buyer's Guide
Has it ever occurred to you that it’s often necessary to specifically ask your original equipment manufacturer (OEM) to add modern lubrication to the bill-of-material when you purchase equipment from that company? Have you ever thought about selecting and specifying equipment based on life expectancy and life-cycle cost as opposed to just the initial cost?
Maybe this is a more familiar scenario: Your OEM includes high-performance filters, breathers and modern sampling hardware as standard items on its equipment. However, your bargain-hunting purchasing agent perceives this as “building the ticket” and asks how much less the equipment would cost without these items. After getting a better price (his goal), the purchasing agent replies, “good . . . sell it to us without the premium filters, breathers and modern sampling hardware.”
Many purchasing agents earn bonuses based on their performance in driving down the purchase cost of equipment. However, these agents are never asked to pay back their bonuses when, later, this same equipment experiences high maintenance costs and frequent failures. A better purchasing strategy for companies is to minimize the life-cycle cost of ownership. When you buy cheap, you are often buying problems. Compounding the issue, once a lowest-price specification is in place, companies tend to buy the same problems again and again.
It’s not the initial cost of the equipment that matters but rather the life-cycle cost (operating costs, maintenance, energy consumption, etc.). Consider the breakdown of the typical life-cycle cost of a common centrifugal pump compared to what might be achieved if modern lubrication hardware and better seals were included.
|Initial Purchase Cost||
$6,000 - 15%
$6,500 - 22%
$12,000 - 30%
$2,500 - 8%
$16,000 - 40%
$15,000 - 50%
$6,000 - 15%
$6,000 - 20%
|Total (Life-Cycle Cost)||
$40,000 - 100%
$30,000 - 100%
In Table 1, modern lubrication and better seals result in an increase in the initial purchase price of $500. For people who buy equipment, this may seem rather unsavory and not the bargain they hoped for. However, for those who view overall long-term business performance, it’s a financial windfall! Actually, more like the goose that laid the golden egg. Put in $500 today and, five years later, get $10,000 in return. This is equivalent to earning a compounded interest rate of 111 percent on a passbook savings account. The net present value on the $500 is approximately $7,727 based on a discount rate of 5 percent. Not bad! Put another way, for those who pretend to save money by buying equipment stripped to the bones: $500 saved is not $500 earned, but rather $7,727 forfeited.
Next, let’s talk about what it costs to buy equipment not properly equipped by the OEM for modern lubrication. When this happens, the maintenance staff is left to engineer, source, buy and retrofit the necessary hardware onsite. Back to the pump example and that initial cost increment of $500. This is what you pay when these parts are included in the original bill-of-material. When this same hardware is purchased and later retrofitted onsite, the cost can increase to $3,000 or higher. Why? Users are not equipment builders and don’t purchase in volume. Aftermarket parts can cost many times more than preassembled machines or systems, not to mention the assembly labor. Take, for instance, that centrifugal pump; it costs approximately 3.5 times more than a preassembled new pump when purchased piece by piece. Even more interesting is an automobile. Bought piece by piece, it costs 17 times more than an assembled one on the showroom floor.
Return on net assets
One factor not considered in the centrifugal pump example is machine availability (uptime) and productivity. When machines are better lubricated, they require less maintenance, as well as less downtime to perform the maintenance tasks and associated repairs. This is perhaps best visualized in the example below showing a metric known as return on net assets (RONA):
RONA = Revenue - Expenses / Net Assets
Let’s discuss each of the variables.
Revenue: A machine can generate revenue only when it is operating. Increased uptime means the machine makes more widgets (BTUs, tons of steel, etc.). When lubrication is at best practice, machines are more productive and revenue increases.
Expenses: This includes energy, maintenance costs (repairs and preventive maintenance), spare parts, etc. When lubrication is at best practice, expenses decrease.
Net assets: This is the cost of machinery and equipment, including modifications, less depreciation. When machines are accessorized for proper lubrication by the OEM and not by the maintenance staff, this decreases net assets.
What’s interesting is that good lubrication practices affect all three parameters, and in the right way: revenue increases, expenses decrease and factory-installed lubrication accessories reduce net assets. The collective effect is an increase in RONA.
Factory-installed modern lubrication
Many OEMs include only the minimum equipment for lubrication as a part of the original bill-of-material. Anything else is optional and, therefore, frequently left off the ticket. These options add to the cost but may generate real value when selected. What follows is a list of lubrication-related hardware and accessories that, where suitable for a particular machine and application, could be factory installed:
Level gauges located near fill ports and large enough to easily determine oil level.
Expanded-metal guards on chains, couplings, belts, etc. Sheet-metal guards restrict easy inspection of lube points and moving seal parts.
Bottom sediment and water (BS&W) sight glasses enable quick inspection of low-lying contaminants and sludge.
Magnetic drain plugs and other magnetic inspection devices enable wear metals to be examined and removed from lubricating oil.
Large reservoirs and sumps should be equipped with inspection hatches and should have lips, gaskets and compression clamps/bolts to control accidental dirt entry, ingression (dirt, washdown sprays, etc.) and air movement.
Oil sampling and analysis
Primary sampling ports/valves should be properly located and installed at the factory.
Secondary sampling port/valves should be installed on many circulating systems.
All circulating systems should have quality beta-rated oil filters at a capture size and efficiency consistent with contamination control objectives.
High-performance breathers should have a capture size and efficiency consistent with contamination control objectives.
Hydraulic cylinders should be equipped where practical with rod boots to control ingression.
Reservoirs should have suitable baffling and be sized to enable contaminants to settle (dirt, water, sludge) and both air and gaseous contaminants to detrain.
Dust protection covers should be installed where grease fittings are used.
An off-line filter (kidney loop) should be installed on many bath/splash-lubricated machines.
Headspace purge or other suitable headspace management equipment should be used with large reservoirs.
Instrumentation (where practical, needed)
Fluid pressure gauges
Free water alarm
Low oil-level alarms
Pressure differential gauges and filter bypass alarm
Air-intake vacuum gauges for diesel engines and breathers
Online oil properties sensors: viscosity, ferrous density, particle count, moisture, etc.
Headspace dewpoint meters
Optimum selection of lubricant-delivery devices based on equipment performance needs: drip, circulating, oil-mist, splash-oiled, constant-level oilers, single-point luber, grease fittings, centralized lube system, spray systems, etc.
Optimum selection of seal type and quality for long-life service to control the ingress of contaminants and leakage.
Use of temperature management systems, including heaters and coolers (as needed).
Availability of grease purge ports where grease fittings are used.
Proper selection of rolling-element bearing seals and shields.
Proper use of lubricant return-line diffuser to control tank aeration.
Installation of pre-lube system for engine cold-starts.
Installation of power-flush quick-connects on tanks, reservoirs and sumps.
Detailed and illustrated lubrication procedures (oil change, grease change, grease add, oil top-up, etc.).
Detailed and illustrated flushing procedures and listing of suitable fluids for flushing.
Oil change interval/regrease interval.
List of all lube points.
Recommended lubricants (performance specification) for all lube points and operating conditions (speeds, loads, etc.).
Brand/type cross-reference for all lubricants.
Equipment storage protection practices/products, including use of fogging agents, shaft extension sprays, breathers and vapor-phase rust inhibitors.
Roll-off cleanliness of new equipment fluids/lubricants.
Run-in procedures for gears and similar equipment.
Seal compatibility information for system lubricants and other fluids.
The best lubrication programs, often referred to as world class, are those that have world-class lubrication technicians, use world-class lubricants and deploy world-class procedures. What must be included is the need for factory-installed, world-class lubrication equipment and devices. It’s time to talk to your equipment supplier.
Jim Fitch is the president and co-founder of Noria Corporation. Contact him at firstname.lastname@example.org or 918-749-1400. To learn more about proper machinery lubrication practices, visit www.machinerylubrication.com and www.noria.com.
Mackay, Ross. “Current Best Reliability and Maintenance Practices of Pumps and Pump Systems.” Results-Oriented Reliability Maintenance Conference. Raleigh, N.C. November 2002.