It's a wide market, so we examined the latest developments through four sets of highly experienced eyes. First we asked Cryomec in Switzerland to give us the very latest in design innovation. Italy's Vanzetti Engineering and Linde affiliates, Cryostar were happy to tell us about the pride and pitfalls behind quality manufacturing. Finally we put it all into practice with some application advice from iGas, based in the UK.

Two sides of the story
In very general terms the pumps market is divided between two types of design and usage. Centrifugal pumps are used in the transfer of cryogenic liquid between storage tanks or road tankers, mostly from ASU units. These pumps have the ability to produce a high flow rate and present a low maintenance requirement. Fully truck mounted systems are also used for suitable applications.

The other product group is reciprocating pumps that are used for filling buffer tanks and gas cylinders. These pumps have the ability to function at very high pressure and present a low NPSH requirement (See side box), a quality shared with its centrifugal cousins.

Different by design
Daniel Mayfarth is one of the sales managers with leading pump designer Cryomec, a company he says are, $quot;generally on the technology high-side.$quot; They specialise in supplying products to gas companies, ASUs, and design for a number of specific gases including hydrogen and LNG. He says designing a pump is different every time as, $quot;each is adjusted to the specific working point of the customer, according to their applications.$quot;

According to Mayfarth this collaborative design process means, $quot;The company has had to adapt our products according to the customer's needs, especially with ASU's.$quot; He also explains that we have not yet seen the peak of pumping capacity because, $quot;Over the year's we have seen them getting bigger and the pumps are bigger and each time we have to develop or adapt a new product or new process solution.$quot;

Despite this growth in capability he believes there are more breakthroughs to be made saying, $quot;The capacity of gas production is going higher and higher.$quot;

For example, the company has recently developed a supercharger to reduce the NPSH for their new hydrogen pump, which allows the user to pump over 800 bar of hydrogen. Mr Mayfarth says the unique achievement came as part of a collaboration, $quot;with one of our partners who really needs this as they are looking to the future.$quot; Certainly hydrogen is one market in which demand is growing, but looking across the industry in general he believes the real challenges will be that, $quot;we need to be thinking about higher pumping capacity, and pressure too - that's true for reciprocating and centrifugal pumps.$quot;

He explains the company's products are always evolving, for example he says, $quot;We recently developed a new motor capacity for our VSMP sealess pump to increase our range capacity and be a technical leader in this field.$quot; Other applications also have room for innovation continues Mr Mayfarth. The company has recently released a process pump with a new sealing system, called the TGPSSL. He describes the principle behind it saying, $quot;Generally when you are talking process pumps you need to have a nitrogen injection, meaning you have a contamination risk to the pumped liquid.$quot; However, the new patented system avoids this problem says Mayfarth, $quot;We take part of the transferred liquid and it is vaporised and injected through the double mechanical seal. This deals totally with the pollution risk and removes the need for a nitrogen injection. This reduces a lot of installation and gas consumption costs.$quot;

Not only does this look better on the bottom line, maintenance time may also be cut by the system. Mr Mayfarth explains, $quot;We expect to increase the period between maintenance visits. This will be the future way for process pumps.$quot;

Thoroughly modern manufacturing
Moving towards manufacturing concerns, Vanzetti says their latest ranges of centrifugal and reciprocating pumps perfectly match with the company's main philosophy of, $quot;easy, modular, and safe.$quot;

Dario Morrica, is part of the cryogenic pump sales team at Vanzetti and he tells us the company, $quot;believes in innovation and always introduces state of the art design.$quot; He says this success comes because, $quot;we design and manufacture the full chain from the cryogenic pump to the last connector of the filling manifolds. When we are designing a pump we are also designing the equipment in the downstream and the upstream so we know exactly the cause and effect of the design of our equipment.$quot;

The latest addition to the Vanzetti range tackles a problem commonly raised by pump purchasers, the time and cost of maintenance. To try and offer a solution Vanzetti has created a product with not only a new flow design but also different ideas about how maintenance work is carried out. Mr Morrica says the new VT-1 pump, $quot;has a different fluid flow within the pump, in fact the inlet is coming from the bottom side and not from the front side. It has a specific design to let the liquid flow more naturally through the pump. This solution reduces the noise and improves efficiency.$quot;

The new unit is designed for use in filling applications and general cryogenic fluid pumping such as cylinder filling stations and more recently LCNG stations complete with full ATEX Ex approvals (Since 1st July 2003, all devices and protective systems that are to be used in situations where there is risk of an explosion must conform to the new Directive 94/9/EC-ATEX 95). Morrica continues, $quot;the other big advantage of this pump is the easy maintenance, it reduces the time of maintenance and cost for the end user. You don't need a specialist mechanic like a conventional pump just one operator that can change the cartridge-seal.$quot;

The company is also testing untouched waters in the market with their VT-2 pump, an extension of the new range available for lower flow rates. He says that, $quot;customers are always asking for (lower capabilities) but is not possible to find from the pump manufacturers. It has a minimum flow rate of 0.3 l/min and a maximum of 1.7 l/min, which is extremely low and we think we are the only manufacturers to be making this product.$quot;

Looking to the future he believes the hurdles ahead will continue in the same vein. He believes, $quot;Our challenge is to extend the range of the product in terms of working pressure and flow rate on the lower and higher side.$quot;

New applications, new challenges
Samuel Zouaghi, is the director for distribution line and clean energy with Cryostar. He says the company's market share falls into two categories, $quot;process and emerging markets such as LNG applications and pipeline injection. Then the distribution line of business meaning pumps, filling trailers and cylinder filling facilities.$quot;

This experience allows the company room to grow as applications develop. Mr Zouaghi says, $quot;The technology that we have been using for cryogenic air gases is readily transferable into natural gas and CO2 sequestration applications and these are growing markets for us.$quot;

Indeed pump manufacturing is growing as fast as the need for pumped products. Last year the company developed, $quot;their biggest cryogenic piston pump.$quot; In terms of performance, the unit $quot;can go all the way up to 300 gallons per minute (1200 l) at pressures up to 690 bar,$quot; says Mr Zouaghi. He also explains that the pump has great potential saying, $quot;This can be used for nitrogen injection but its core application is the EOR (Enhanced Oil Recovery) market which injects nitrogen into gas wells at high pressure.$quot; Cryostar is also looking to non-traditional markets, such as nitrogen of natural gas as it comes onshore and Cryostar's products are already in use at a floating LNG terminal in the UK.

Looking towards the future, he says, $quot;Our biggest concern is to work on product durability, meaning reducing maintenance and increasing the lifetime of our products. We see an obvious trend, which is more flow and more pressure. This has always been the case but it is even more the case now.$quot; He also believes that the market has much potential for growth saying, $quot;There's a battle between compressor and pump technology. Are we going to pipe gas or pump liquid for these applications? There's a high chance that pumps will be used as they are more reliable and cheaper to buy.$quot;

Mr Zouaghi and others also explain they notice a shift in customer requirements. He says, $quot;We are seeing a trend towards getting the most uptime you can from your product and easy maintenance but on the other hand users are calling for more and more outsourcing of maintenance as we see it now.$quot; Essentially this creates a market where customers are looking for more than just design, manufacturing and delivery.

According to Zouaghi, $quot;What we typically sell now are not products themselves but a lot more solutions based on complete care.$quot; For Cryostar the market has become about more than just the finer details, $quot;We sell a flow, a pressure and an uptime.$quot;

Putting pumps into practice
Rob Lee is the business director for iGas, a gas technology solutions company based in the UK. He is a veteran of providing 'turnkey' industrial gas project solutions to the industry, and recent projects have included two 300 bar cylinder filling stations in Norway, and two high-pressure, high-flow nitrogen delivery systems, one in Wales and the other in the North East of England.

He tells us, $quot;iGas has experienced year on year growth of 60 to 70 percent in our cylinder filling systems, and high pressure supply solutions business. There are two reasons for this: our advanced system offerings and use of only the very best equipment from our strategic partners.$quot;

iGas work with their several leading pump manufacturers, which he says have, $quot;a robust design and focused approach. Clearly they understand the way pumps operate and some of the harsh conditions they come under.$quot; He believes that from a successful installation point of view, design and manufacturing need to be of the highest quality. In practice, the products he uses boast a, $quot;fit-for-purpose design that can cope with not just the ideal situation. If you have a brand new installation that's less of an issue, but when you start retrofitting pumps you have circumstances that are beyond your control, that's when the really key features of a well designed pump comes into play.$quot;

For him, the most crucial design measure will be that a unit, $quot;can be put in many environments and operate with same high levels of reliability.$quot; Maintenance again forms a key concern for Mr Lee and he explains that the pumps he uses, $quot;in terms of running hours and clean operations shine through. Capital costs are a factor in purchasing but for those running the pumps the issue will be how much they cost to run? How reliable are they?$quot;

Based on this he echoes other contributors saying companies will work hard to improve the working hours of pumps. Currently a pump may run for around 2000 hours before engineers need to re-furbish the cold end, and manufacturers are working to bring this up further.

Overall the issue is understanding he says, $quot;It's understanding the basis of good product and system integration design. The key issue, is ensuring you keep the best quality liquid on the head of the pump at all times and you have the right equipment to do that - that's the bottom line.$quot;

Final thoughts
So finally, our brief survey of the pumps industry leaves us with a couple of recurring threads. Maintenance continues to be an expensive and time-consuming pursuit, with both manufacturers and consumers pushing to lower time spent offline. Other developments follow more general trends in the wider industry, as designers prepare for higher (or lower) pressures and capacities to come into common usage.

What's the secret to being ahead of the market? As many of our contributors explained, today's industry is about more than pumps alone. Customers are increasingly expecting an individually designed product with a full service package behind it.

What does this mean for the market? If the players mentioned here are to be believed, the flow of innovation pumping through the industry will bring bigger, faster and easier products.

Cavitation and NPSH
•Within a unit as the liquid passes from the pump suction to the eye of the impeller, the velocity increases and the pressure decreases.
•There are also pressure losses due to shock and turbulence as the liquid strikes the impeller. The centrifugal force of the impeller vanes further increases the velocity and decreases the pressure of the liquid.
•$quot;Cavitation$quot; is a symptom of improper pump performance as a result of these drops: a hard metallic knocking noise which is caused by the collapse of the gas fraction inside the cylinder during the pressure stroke of the pump.
•The NPSH Required (NSPHR) is the positive head (pressure) in feet absolute, required at the pump suction to overcome these pressure drops, and maintain the majority of the liquid above its vapour pressure.
•The NPSHR varies with speed and capacity within any particular pump. Pump manufacturer's performance curves normally provide this information.
•The absolute suction head available at the pump inlet is termed the Net Positive Suction Head available (NPSHA).
To avoid cavitation, the available NPSH must be greater than the required NPSH.