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NEUMAN & ESSER services 11 orphaned compressor lines

Legacy Equipment Gets OEM Support 

 

At the end of the last century, it was commonly thought that the reciprocating compressor era was ending and no recip would remain in service beyond 2010.

During the industry consolidation of the 1980s, many recip manufacturers decided to stop production of these machines altogether, a decision that created problems in the relationships between customers and the OEMs who had recently supplied them with recips.

Who would perform necessary services and supply spare parts for a piece of machinery with an expected lifetime estimated at more than 50 years?

The OEMs’ recip specialists were assigned to other product lines and the customer-OEM contacts were getting looser and looser with increasing customer dissatisfaction.

This situation reached the point that the old OEM, not to compromise its reputation on the marketplace, had to find a solution that would satisfy its former customer.

NEUMAN & ESSER (NEA), which never believed that recips would become obsolete, took a chance and in 1988 established NEAC Compressor Service. The new business signed a 50/50 joint venture agreement with Atlas Copco to service its recips, which comprised the KSB and Linde brands together with NEA and Halberg compressors.

The experiment, as well as being successful for both parties, proved its value for the customers who had again a direct contact with an active compressor manufacturer. After 10 years of successful operation this JV was finalized. Since then, NEAC Compressor Service continues its business as an entity of NEA Group.

 

A manufactured and aligned GHH hyper crosshead and traverse posi-tioned on a master bed

NEAC Compressor Service services a portfolio of 11 legacies. In addition to the above-mentioned brands, the lines are: Erhardt & Sehmer, Demag (Brazil operation), Mafa Wurzen, Chicago Pneumatic, GHH Esslingen (high-pressure compressors), Borsig (for the former recips built in Berlin until the end of 1995) and Penn Process Compressors.

NEA is the only company that has implemented a policy to become an OEM service provider for legacies, although other companies have picked up brands through acquisitions, such as Cameron has done via mergers with Ajax, Superior and Cooper-Bessemer.

NEAC supports only the reciprocating compressor product brands for which it has purchased the exclusive right to service and received the original documentation (parts lists, specifications, drawings, history/modifications of the machine, etc.).

Although the scope of service is the same, each OEM had its own organizational and filing system, so NEAC has maintained the manufacturer’s original systems under the supervision of a legacy manager for each equipment line.

This is an assembly of NEA’s vertical compressor for the polysilicon industry

Extensive database

Bernd Wagner, managing director of NEAC Compressor Service, told COMPRESSORtech2 that generally speaking, all old compressors still in service are healthy machines that need maintenance, not modifications. If a piece of equipment was not properly designed, the OEM detected those design faults and solved the problem during the early years of service.

Wagner said when new components are needed for major maintenance operations, they should be manufactured according to the original drawings and using the same materials.

Legacy equipment failures not caused by normal wear are usually due to three main causes: foundation changes, process changes or use of components that are not to spec or have excessive tolerances.

Wagner said re-engineering is a dangerous process because it has the potential to introduce unknown variations in the system that could initiate a chain process that gets out of control. Only when the original documentation is incomplete or there is a variation in the process does NEAC engage in re-engineering, and always with the cooperation and approval of the compressor owner.

NEAC has established a database comprising over 5500 compressors, of which 40 to 50% are legacy equipment and the rest are NEA’s own machines.

The legacy number is destined to decline over time due as the old machines end their service life while NEA machines are increasing due to the present rate of production. However, this is a long-term process since the life of a process recip is about 50 years. (Many horizontal compressors of the 1930s and early 1940s are still in service.)

The database essentially has two parts.

The commercial section files contain details of the customer and of the compressor, when a specific service was required, when new components were ordered, and other commercial information.

The technical section features, for each compressor, a dedicated dashboard showing every component with different displays, drawings, service reports, technical reports, compliance section, changes section, etc.

All NEAC Compressor Service centers worldwide have access to the database so they can closely monitor the conditions of the machines operating in their area of responsibility.

More than 50% of the compressor population registered in the database is active within a two-year period. Each legacy line has a turnover between 3 and E5 million/year, making an important contribution to NEAC’s business.

As these legacy lines become obsolete and as equipment is retired, NEAC will drop its support. Wagner said so far, only the Chicago Pneumatic legacy line has been declared officially closed, although some orders for spare parts still are coming in.

Maintenance challenges

As well as supplying original spare parts for the legacy equipment, specialized NEAC personnel assist or directly conduct maintenance operations on the customers’ compressors.

One of the most challenging operations is the alignment of compressor components after a major overhaul. This operation becomes particularly difficult for large process compressors built in the 1930s and 1940s that are still operational.

The architecture of these machines features a central low-speed electric motor with two cranks, one on each rotor shaft end, driving two connecting rods placed inside two separate compressor frames. Each frame features a line of horizontal cylinders performing the various compression stages.

In the old days, the alignment of the cylinders on their frame and of the two compressor frames with the common motor was achieved by using strings under tension, a technique that (despite being very time consuming) is still used and, if carried out by skilled personnel, gives excellent results.

NEA demonstrated its 3-D laser tracker and mobile machining tool at its 25th anniversary customer event last year
Two-dimensional laser equipment is set up for main bearing bore alignment verification

However, NEAC specialists are equipped with 2-D portable laser devices, one for each continent, which are used to perform this operation much faster. Lasers also check alignment on large frames featuring a multiple-crank crankshaft. These frames are very rugged, but sometimes they are assembled on a foundation blocks that over time have lost their flatness for various reasons, including lube oil leaks.

A twist of the frame may misalign journal bearing housings, compromising compressor operation. The 2-D laser devices are also used to perform such flatness checks in the field while 3-D lasers are commonly used for form and position verification in-house as well as in the field.

Harry Lankenau, NEAC’s head of engineering and technical support, said regardless of the methods used to collect data, whether with a string or with a laser, experienced personnel are needed to know what to do with it. Although the latest generation of instruments guarantees higher precision, the data has to be properly used.

Corrosion of two matching surfaces may compromise alignment. In this case, re-machining of the surfaces is necessary. This operation is performed on-site with portable machines if possible; otherwise the component must be taken to a service shop to re-establish surface planes.

When a component has to be replaced, NEAC uses the original documentation to manufacture a part that exactly matches the original. If the documentation of a cylinder or frame casting is incomplete, or the old files are illegible, an optical scanning technique may solve the problem. Optical scanning can redesign replacement parts two-thirds faster than they can be done by hand. 

NEA refurbished this cylinder of a Halberg high-pressure compressor