Paul C Banard, Deepdene Consulting Ltd
C.Eng. M.I.Mech E.
I have been associated with the pump industry for only a couple of years short of the time that World Pumps has been in existence. During that time, I have seen many changes, some good – some not so good. I have seen innovation; I have seen old companies die and new ones borne out of mergers and acquisition. It has been an exciting time from the slide rule to silicone chips. Pumps have changed from packed glands through seals to sealless pumps. Materials have changed to make short life wear out problems almost a thing of the past.
During my career, progress has moved in three major areas of pump technology. Design has progressed from slide rule and graph paper to computing and finite element analysis, while the understanding of fluid flow has advanced enormously. Cut and try engineering art has become rapid prototyping and now three-dimensional computer modelling directly connected to five axis machining. Taking a design concept to completed product is now completed in days, not months.
A second area of progress has been in manufacture. Machining has moved from multiple machine operations on hand operated lathes and milling machines to multipurpose machining centres. With the change in manufacturing machines has come increased accuracy. Repeatability, interchangeability and surface finish have improved. The improvement in manufacturing techniques has helped the introduction of special steels, ceramics and other hard sintered materials.
The third area of pump technology to change is how we use pumps. Pump installation is now more refined so that pipe design and base plate design are considered together, removing the old problems of distortion and miss alignment. I recall seeing a marked improvement in pump life when plants changed from random hand control to pneumatic control, and again when full plant integrated computer process control was installed. A gentle hydraulic start up and keeping the pump on its operating curve over its best efficiency range have greatly prolonged life.
Frequency converters
The introduction of digital variable speed frequency converters, allowing pumps to run at an optimum speed both sub and super synchronous, all help to keep the pump on its operating curve and over its best efficiency range while introducing real power savings.
Pumps are normally purchased to be installed and run – they are not normally purchased to be in the maintenance workshop. Advances in vibration analysis, frequency spectrum analysis, thermographic analysis and noise analysis have come with digital tools, while advances in lubricant technology and the introduction of synthetic oils and greases have led to prolonged operating life, and the analysis of oil samples has led to monitoring systems and hence predictive maintenance that is real.
However, with the advances in world of pumps, in parallel with the computational revolution, has come an explosion of bureaucracy. It is my considered opinion that the wealth of standards, work and environmental legislation, that is now in place and growing, has lead to the slow decline of inventive engineering. It is becoming harder and harder to get new ideas in place through a forest of rules and regulations.
Safety considerations
Mechanical seal are a good example. Safety is a major consideration in the petrochemical industry where any penetration of the product pressure-containing envelope is a weak spot. Pump seals are the weakest. Understanding the seal face thermodynamics, improving the seal face materials and ensuring clean correct assembly has gone a long way to improving their reliability. Understanding and improving the pump shaft rotordynamics and bearing design has gone a long way to giving the seal a smoother ride, but still the seal is the weak spot of the pump. Sealless pump technology has been slow to get wide acceptance except in the home central heating and fish pond business, where I suspect most customers do not understand how pump works or what its overall efficiency is.
It amuses me that when Scotty emerges from the engine room of the Starship Enterprise and Captain Kirk asks him what he has been doing, he never replies that he has been fixing a mechanic seal on a pump. I hope that the next 50 years will see a wider acceptance of current technology along with new and inventive means of pumping fluids that do not involve a penetration of the product pressure-containing envelope.
L M Teasdale
C.Eng. (Ret'd), F.Inst Energy (Ret'd), F Inst Gas E (Ret'd), Eur Ing (Ret'd), Engineering Director of BPMA (Ret'd), EEC Consultant to CEN (Ret'd), Lifetime Achievement Award 2003 from BPMA.
The changes that I have seen in the pump industry really began for me in 1974 when I was appointed to head the engineering activities at Worthington Simpson in Newark, UK. These can be broadly broken into technical and commercial. Undoubtedly, the main changes have been in the commercial scene, although much of them have been driven by technology developments.
The emergence of digital controlled machinery increased both investment and productivity. This meant that for several years the industry existed with massive excess production capacity together with a need to finance substantial new investments. The result was mergers and acquisitions on a wide scale, both within national boundaries and then quickly across the international scene. Although the pump industry was always international in its activities, the emergence of newly developed countries, bringing markets as well as their own manufacturers, added to the mélange.
Of course, international companies had existed before but all, large and small, experienced heavy competition. It took a couple of decades to sort it out and produce the present shape – and that assumes that the process is finished.
Labour costs have also led users to farm-out aspects of their pump coverage. They now range from contracts with third parties for the supply and maintenance of ‘pumping services’ to simple service contracts without in-house back-up of specialist pump people. The user now has little in-house expertise, relying instead upon buying this from external sources.
Complex picture
Technical developments give a more complex picture. Firstly, pump makers are required to respond to the users’ requirements. As these have changed, so have the pump products offered. More aggressive or higher temperature pumped product has involved using more sophisticated materials. High service labour costs have required more reliable equipment. Costs have also driven down material content, giving more compact units, and faster operating speeds. Safety has complicated pump component and pump design. Operating ranges have been widened, service intervals extended, installation and servicing hazards have been reduced, and operating efficiencies have been steadily raised.
The internationalization of the industry stimulated much activity in widening national standards. For pumps, these were mainly dimensional standards. The stimulus of the EU drove this very hard within Europe and there was a pause in the wider international scene. It also widened the area of standardization into machinery safety, pressure vessels, and many other new areas which were not aimed at pumps but which captured them. Eventually, standardization moved back into the world scene and international standards were produced.
The changes in the technical scene have been accompanied by a very welcome focus on training. At the start of my career, pumps technology was seen as a part of mechanical engineering. Fluid flow was treated simply as a topic within this wider discipline. In fact, it has always been an amalgam of largely mechanical engineering and electrical engineering, but with aspects of chemical engineering, control engineering, production engineering, materials technology, and a smattering of hygiene! In the past, this made formal training difficult and ‘on-the-job’ training gained from ‘Nelly’ and through experience was the practice. Now, the industry has training routes for gaining these essential attributes that lead to specialist formal qualifications.
It is a strange co-incidence that the 50th anniversary of World Pumps should occur in the 50th year since I started my time in the industry. There will be more years from me, several I hope, but they will be blanks, just crossing off another year. For the pump world, they will be years of real activity and I wish it well as it starts its second half-century.
David T Reeves
B.Sc.(Eng.), C.Eng., A.C.G.I., F.I.Mech.E.
I had just finished my two year graduate apprenticeship to W H Allen Sons and Co. Ltd., Bedford, UK. My ‘fitting test piece’ had been to transform (by hammer, chisel and file) two pieces of round steel bar into rectangular shapes, with one passing through the other in any direction, losing 1% for every one thou gap or out-of-square or off-centre. This left me with bruised and blistered fingers and a lifelong admiration for all skilled craftsmen. In later life, when interviewing for new staff I always asked about their workshop experience. If none, they were off the list. Today, I suspect I would finish without a list!
Well equipped
The pump department had its own well equipped Fluid Flow Lab, where I was able to gain hands-on experience of scaled intake model testing, field problems, efficiency improvement, etc. I reported to a Mr Guppy, who kept a drawing board in his office and when a really important job came along (eg a large high head pump for Rand Water), he would design it personally.
Later I applied for a job at Harland Engineering in Alloa, and was given me a Saturday morning tour of the Works. When I saw a large boiler feed pump set up for test with its mountings rigidly welded to the floor rails I thought ‘no-nonsense Scottish engineering’ and decided this was for me.
While at Harland, we entered the world of computing by modem connection to an agency, with programs and data on punched tape. I insisted that all my designers learnt BASIC computer language and any of them could write or modify a program, provided they could convince me that it would be worthwhile. Thus they all understood how the computer output was derived and whether it made sense. If only this was still the case.
Come the recession of 1983, Alloa was practically closed down. Fortunately, it was not long before Worthington USA decided they needed a ‘Director - Fluid Machinery Design’ based in Europe. It was my job to keep an eye on and contribute to the R & D work going on in eight of Worthington's 35 plants worldwide. I visited many of the US and found the engineers to be highly articulate.
In late 1984, Dresser acquired Worthington from McGraw-Edison. Having been in the wrong place at the wrong time twice, I decided to work for the only person who couldn't fire me; myself. Working for dozens of very varied clients (makers, users, contractors, consultants, etc.) has been fascinating. The largest single client has probably been working with AEATechnology for the EU on the ‘SAVE’ project (which led to a useful brochure on pump selection for efficient operation) and the EuP Pump Directive (which is intended to raise the minimum allowable efficiencies of pumps sold into the EU).
In retrospect, I feel highly privileged to have spent 50 years in a fascinating industry during times of great change and to have known many brilliant engineers, far to many to list here. I wish World Pumps (and myself!) another fruitful 50 years.
Eur Ing Lez Warren
D.L.C, D.M.S, C.Eng, M.R.Ae.S, M.C.M.I, C.Dip.A.F.
In 1959, I was a scientist at the Royal Aircraft Establishment, Farnborough. I had the task of devising a method to keep a pilot looking through the TSR2 windscreen in rain of 4 in per hour. The TSR2, a Tactical Strike and Reconnaissance aircraft was designed to fly about Mach 1 at ‘Hell's Angels’ – hugging the ground to stay under the enemy radar. Initial test were to be made in a wind tunnel. For this we needed to make ‘rain’.
To make the rain we needed a small high-pressure pump. The only high-pressure water pumps available were relatively large and expensive, complete overkill. We settled for using a swash plate fuel pump. This pump was not suited to run on water. However, it fitted into the pattern of our experimentation. We would run some tests, and while I was analyzing the results, the fitter was refurbishing the pump for the next tests.
Having devised a system, it then remained to test it ‘live’. We fitted the gear on to a Javelin and took it to Singapore where there were daily showers at 4 in per hour. The photograph shows the team in 1960 at Changi. The author is wearing the white socks. Unfortunately the TSR2 was cancelled before it was even through the prototype stage.
Little did I know at the time that some 14 years later I would be managing a company selling small high-pressure water pumps. This was a branch of an US company, which pioneered a range of reliable piston pumps for water. Then, as now, the vast majority of problems with high-pressure pumps arose from inadequate inlet systems. It would be seven years before a better understanding of the problem was determined. Other manufacturers had followed the American lead and were offering competing products, not always with the best interests of the customer or industry in mind. Standards have improved in both product and marketing.
Limitations
The limitation of piston pumps is the strength of the piston seal. As pressures increase above 100 bar, the seals start to be forced backwards. Larger high-pressure pumps had been available, and these were plunger pumps (a piston pump has the seal moving on the piston within a cylinder, a plunger pump has a stationary seal and a cylindrical plunger). The material for these plungers was of various materials, and generally running in rope packings. The plunger surfaces were subject to a limited life and the packings, which had to leak to stay cool and lubricated, needed constant adjustment to control the leakage.
Various surface finishes are applied to these plungers, even today, but there is always the underlying problem of lifting of the surface from the substrate. Alumina and Zirconia ceramics became available in the late 1970s and were fashionable into small plungers. Even today there is a limitation on the size of such a plunger that can be produced. Plungers with new sealing systems made of high technology materials allow the small high-pressure water pumps to achieve high pressures and increased reliability.
Since that time the size of available plungers has increased and hence the product range of mass-produced plunger pumps. They have gone from flows of 15 lit per minute to that of 1000 lit per minute and pressure have risen from 100 bar to 500 bar. Specialist pumps exceed these ranges.
From the mid-1980s the American Petroleum Institute has published standards for these positive displacement pumps. These have been developed over the years and are now produced as ISO standards for the petro-chem industry. Following on from this, ISO has produced standards for general applications of high-pressure pumps.
Over the past 15 years the market has matured and the improved efficiency of high-pressure pumps (c. 90%, with 8000 hours before the need for minor servicing) has made them increasingly viable. The availability of low-cost, reliable, variable speed drives has widened the appeal for these efficient PD pumps. One of the driving forces for this energy saving is the use of life cycle costing in pump procurement.
