Industrial Pumps Blog

Increasingly tighter regulations are being implemented worldwide to curb the use of sulfur-based fuels and the pollution which they create.  The European Union is one of the world’s leading trading blocs and also is leading the way in the use of legislation curtailing the use of “dirty fuels” on ocean going vessels.  The challenge for ship and fleet owners is that while they may have vessels which comply with regulations in say, the Far East, but which must now comply with the much tighter controls which exist in the European Union.

One example of marine pollution regulations which are causing serious engineering and fuel issues for ship owners are the European Union’s MARPOL (Marine Pollution) Annex VI Regulations for the Prevention of Air Pollution from Ships. These regulations prohibit the burning of sulfur-based fuel oils and provide for a strict timetable for implementation around various ports around the world. For instance, there are stated reductions in the emission of sulfur oxide (SOx) variants, carbon dioxide (CO2) and nitrogen oxide variants (NOx).

Additional EU Directives enabled in 2010 mandate that ships which are docked for more than 2 hours must use marine fuel oil which has a 0.1% or less sulfur content. For many operators, this means they must switch between fuel sources when they are in port to MGO – marine gas oil which is low sulfur but which is a poor lubricant because of its low viscosity.  In turn, the poor lubrication qualities will impact on the ships’ pumping systems and general machinery.

This contrasts with the situation prior to implementation of pollution emission regulations.  High-sulfur fuels could be used, which had good lubrication properties or lent it to being heated in order to improve pumping functionality.  Now low-sulfur fuels must be used which are already less viscous and would require excessive heat to be applied which is not feasible in an engine room (where the ambient temperature is typically around 40 degrees C and in some instances reaches 55 degrees C). The change in operating conditions needs cooling systems to reduce the oil temperature in order to thicken the oil so it can be pumped efficiently.

Increasingly stringent regulations are becoming more of the norm for the global marine industry, particularly in the areas of sulfur emission control and pollution impact upon the environment.  The European Union has spearheaded sulfur emission legislation and certain notable hotbeds of environmental legislation are following in the United States.  It is only be a matter of time before federal law and regulation ties operators to more stringent requirements and this is impacting pump design in various ways.  One key issue with pump design is the ability to self-detect and alert operators to leaks, impending failure and other prevention features.

It is not simply environmental considerations which are driving industrial pump development as on board a ship, any leak in confined space has the potential for calamity, particular in machine rooms.  Whereas previously tolerable leaks could be ignored for operational purposes, this is no longer an option if the operator is to comply with safety ratings or satisfy the commercial need to control costs.

The key commercial issue with self-detection and prevention has been to design and implement a cost-effective solution.   One issue is found in the question, “When is a leak not a leak?” – mechanical seals require lubrication over their moving surfaces otherwise the pump will quickly degrade and fail, so lubricant leakage has practically been inevitable. (more…)

Multiphase or tri-phase pumping solutions are commonly found in oil and gas fields and their application is increasing as a direct consequence of increases in drilling operations.  Multiphase pumping solutions allow for simplification of the upstream drilling operation and also provide for smaller and less costly pumping installations.

Typically, a multiphase solution will deal with all of the fluid stream characteristics using an integrated piece of machinery instead of using different, discrete equipment units.  It is usual to find twin-multiphase units in operation rather than a single, larger installation and it is not uncommon to find three-multiphase units installed in series.

Multiphase solutions also find application in midstream and upstream operations, both onshore and offshore and may be serve single or multiple wellheads.

Multiphase solutions are used to transfer crude oil and gas from the wellhead to the downstream facilities, either for further processing or in the storage farm.  The multiphase solution is capable of managing anything from 100% gas through to 100% fluid and intermediate mixtures, which may also incidentally contain abrasive detritus, such as sand from the operation as well as managing varying flow and pressure rates.  However, a major environmental attraction is that multiphase solutions substantially reduce the emission of pollutants, particularly greenhouse gases by reducing the requirement for tank venting and flaring of excess gases.

There are five main categories of multiphase pumps:

• Twin Screw – Positive Displacement (PD) – comprises twin, intermeshed screws which find common pumping application for high-gas content product or where there are fluctuating input rates;
• Helio-Axial Pumps – Centrifugal – sometimes referred to as the Poseidon Pump, this uses one rotodynamic pump operating along a single shaft;
• Progressive Cavity – PD – used in shallow or surface wells where fluids may have a high solid content (typically sand or earth);
• Buffer Tank – this is usually found upstream and eradicates variable input flow rates and also reduces the level of solid detritus in the fluid stream; and
• Electric Submersible – Centrifugal – typically used when the liquids are being pumped and are used to provide artificial lift.

The last Presidential election encompassed the debate over whether to commence offshore drilling operations in our territorial waters in order to reduce our reliance on overseas oil producers.  Whatever the eco-political debate on drilling off our shores, it is a reality that the Gulf of Mexico presents significant engineering challenges and is a prime oil production region for the United States and the world.

The Gulf has seen a rapid expansion in the number of drilling platforms which is set to continue given the increased efforts at uncovering hidden reserves.  The spate of hurricanes over the last few years did create a block on oil and gas production, however this has been reversed and production now exceeds the 2006 production numbers (470 million barrels of oil).

The principal challenge facing operators is the effective operation of deeper wells in the shallow water zone, typically operated by chemical injection.  Shallow water projects are those which take place within 1,000 feet of water while deep-water projects are in excess of this.  Gas drilling operations further split shallow water operations using the TVD (true vertical depth) of the production field and the water depth.

The main problem is the formation of hydrates which will result in costly platform shutdowns.  The increased pressure due to deeper wells, low sea temperatures and extremely lengthy tie-backs all mitigate in favor of extensive hydrate formation.

Another issue is the environmental implications of drilling operations in such as sensitive area.  Oil and gas production utilize equipment and raw materials which will result in severe environmental impact should there be an accidental discharge.  Handling harsh and toxic raw materials requires robust and reliable storage and pumping solutions together with secure redundancy and fail-safe systems.

Finally, there is the harsh environment posed by the salt water sea.  This is highly corrosive, however there is another issue posed by the salt-water environment.  Methanol use produces very hard, abrasive rust particles which will cause severe damage to pumping mechanisms.  Countering this are the pumping systems transferring the range of chemicals to counteract the impact of the environment upon the drilling infrastructure.

Noise and vibration form a key side effect of almost any industrial application or process you can think of.  They are also negative factors for a number of reasons – they are pollutants, they may harm human operators and persons in the vicinity, they may adversely affect performance and indeed, excessive noise and vibration is symptomatic of energy and operational inefficiency involved in the process.

There are also instances where for operational reasons, noise and vibration must be minimized.  The French Navy has recently placed an order for ultra-silent industrial pumps to be fitted to its new class of “Suffren” submarines.  When a submarine is engaged on duty or operations, it is essential that the vessel can operate under the strictest standards of silence to evade detection by the enemy.

In such instances, there is no alternative but to deal with the noise and vibration issue.

Industrial pumps and fluid handling systems contribute a large portion of the noise and vibration associated with any industrial or military process (obviously this applies only in normal circumstances).  Traditional centrifugal pump technology utilizes techniques which are themselves, very noisy and contribute to vibration production.  By definition, greater part movement and friction creation is implicit in the operation of centrifugal pumps which makes them inappropriate for designs intended to meet high environmental and operating efficiency levels.

To this end, it is noticeable that positive displacement technology is increasingly being used by commercial and military operators seeking to deliver noise and vibration free side effects of their activities.  Positive displacement pumps and valves are also much more efficient in terms of consumption of energy and enjoy greatly reduced operating costs due to extended maintenance and replacement cycles.  The new French submarines for instance, are utilizing positive displacement pumps, rather than old-style centrifugal technology which cannot deliver the same operational standards of silence and reliability as the newer technology.