Innovative linear motion products from THK are making it possible to produce quieter and more compact operating mechanisms for sliding doors in elevators and general building applications. With noise levels reduced by up to 50% compared with conventional products, the new mechanisms minimise the disturbance created by a door opening and closing - a benefit which is particularly important in quiet environments, such as hospitals and libraries. The smaller size of the new mechanisms allows them to be accommodated in a slim enclosure which is, in most cases, mounted above the doors.

This means that, for a given size of door aperture, more space is available for the doors themselves, greatly improving the overall appearance, especially with fully glazed doors.

Particularly well suited for sliding door applications are THK SNS- and SHS-series guides.

These are four-way equal load products that combine a high load rating with rigidity and precise operation, and which are available in a wide range of sizes.

SNS and SHS guides are easy to install and are offered with a wide range of options, including seals, scrapers and covers, which allow them to be readily configured to match the application.

Like all products in the extensive THK range, SNS- and SHS-series guides incorporate the company's proven and industry-leading Caged Ball technology.

Balls roll in raceways that are precision-ground in the LM rail and block, while endplates incorporated in the block allow the balls to recirculate quietly and smoothly.

The Caged Ball system arrangement eliminates friction between the balls, and increases grease retention, thus giving the guides their low-noise, low-friction characteristics, and also ensuring long, maintenance-free working lives.

Caged Ball technology also means that, for a given load capacity, THK guides are smaller and lighter than their conventional counterparts.

Novel slide and tilt mechanism built using a material combination of polymers and aluminium promises more flexible hide-away stowage with effortless access.

A new slide and tilt mechanism built using a material combination of polymers and aluminium is being introduced by GSF to create more flexible hide-away stowage yet giving easy, effortless access. With a preference for plastics in this latest design, GSF has been able to create a system 50% lighter than previous models, stronger, requiring less maintenance and expected to last longer than all steel components. The basic design concept of slide and tilt enables component drawers, even tote bins to be stored horizontally and when access is required to high level drawers they can be simply and safely pulled forward and at a predesignated distance the tilt mechanism comes into action, lowering the front edge of the tray to a preset angle.

This versatile system adapts to diverse requirements, not just supporting trays and bins, it will be equally at home holding equipment that needs to be rack stored.

In developing the new mechanism GSF have incorporated plastics wherever possible to reduce weight whilst simultaneously improving length of service life, hence a 20 year lifetime guarantee.

It has also contributed to a much wider specification with a temperature range of -20 to +100C, an environment of 100% humidity as well as being suitable for full immersion in water.

The new slide and tilt mechanism from GSF also benefits from an ability to withstand shock loads and extended vibration.

The new slide and tilt mechanisms is a two part device, a mounting bracket assembly that is mounted immediately below the ultra-smooth running linear rail, the distance dependent on tray depth.

Within this injection moulded bracket there is an adjustable side roller for precise control over the drawer movement, preventing any slewing or possible jamming.

The versatility of the new slide and tilt mechanism developed by GSF is attributed to its composite carriers.

Two fully shielded ball bearing action rollers embedded in the carrier mould contribute to the effortless movement along the aluminium carrier rail and are central in creating the smooth pivot action of the tilt operation.

GSF has considerable experience in manufacturing slide and tilt mechanisms, previous designs have been all steel construction.

Jeremy Binnington, Sales and Marketing Director, believes the company's existing steel models will remain a firm favourite with many customers due to loading requirements.

'However, we expect the new plastics design, which still has an impressive load specification of 70kg, will enable use to win business in new market sectors including general storage and warehousing applications', he says.

Space and cost savings, enhanced precision and outstanding reliability are among the key benefits that innovative linear motion products from THK, the world's largest dedicated developer of linear motion technology, are delivering in a wide range of printing-industry applications. Underpinning these benefits, in application areas from prepress to finishing, are linear motion guides based on THK's proven and industry-leading Caged Ball technology. This innovative technology allows the company's products to combine smooth, silent motion and high levels of positional accuracy, with exceptional load-bearing capacity and long, maintenance-free working life.

Caged Ball technology also means that, for a given load capacity, THK guides are smaller and lighter than their conventional counterparts.

Among the many examples of the use of THK products in the printing industry are plate making machines fitted with type SSR radial guides, which are designed for long life in high-speed applications.

The SSR guides provide smooth movement and low variation in rolling resistance, guaranteeing the high positional accuracy needed for the dependable operation of the machines.

In gravure printing machines, type SHS four-way equal-load guides have displaced an earlier solution for turner bar register adjustment, which used no fewer than 16 precision bearings at each station.

The new arrangement reduces costs by approximately GBP 500 per station and, since each machine has a minimum of 16 stations, this translates into substantial overall cost savings.

In the post-press sector, type SHS guides are being used in bidirectional board-cutting machines, where their smooth motion and rigidity are important benefits, and where their small size has allowed a space-saving design to be developed for the machine.

Knife-cutter machines are also being enhanced by the incorporation of THK products.

Type SSR guides are allowing the operating speed and, therefore, throughput to be increased by as much as 20% compared with machines designed around conventional ball bearings.

Pulstronic is a proportional valve designed to provide precise and cost effective proportional pressure control for applications requiring a constant flow

The Asco Joucomatic Pulstronic proportional valve is designed for pressure control applications requiring a constant flow: these include turbine speed control, glue and lacquer dosing, pressure control of welding equipment, and flow control over nozzles. Pulstronic is a self-contained, electro-pneumatic proportional valve with an integrated control loop that provides precise regulation of pressure. Designed for operation on normal filtered air (50 micron), Pulstronic employs the innovative Asco Joucomatic poppet technology - proven on the market leading Sentronic proportional valve - to provide good rates of response with minimum hysteresis (< 1% of maximum output pressure (PMR)), when increasing or decreasing pressure.

In addition, repeatability is excellent at 0.5% of PMR (10bar).

The IP65 rated Pulstronic is available in four versions: the DN4 with G1/8 ports, the DN7 with G1/4, the DN12 with G1/2 and the DN05 with instant fittings to accept 4mm flexible hose.

The latter version is particularly adapted for piloting pneumatically operated valves or boosters.

All the valves operate with analogue set points of 0-10v, 0-20mA or 4 - 20mA, and offer operational security in the form of a 'pressure held at power failure function'.

Typical applications where the Pulstronic provides an optimised control solution include: Compensation of thickness on pinch rollers, Spot Welding, Turbo-supercharging and Materials Testing.

In pinch roller applications, Pulstronic controls the pressure acting against the top roller (in a series of two), ensuring that the thickness of the processed material remains constant.

Similarly, in spot welding the Pulstronic valve controls the pinching force of the welding head depending on the material to be welded and its thickness.

In turbo and supercharging applications the Pulstronic adjusts exhaust gas flow to the turbo-supercharger, depending on the engine speed, to maintain the charging pressure at a constant level.

Finally, in material testing the Pulstronic continuously increases the force acting against a test piece until the latter is destroyed.

Further information regarding the Pulstronic, Sentronic D, Piezotronic and the Asco Joucomatic complete range of proportional valve products is contained within a new 25-page catalogue produced by the company.

The publication provides all relevant information regarding proportional technology and devotes four pages to application examples, each with its own accompanying graphic.

Plast-O-Matic Series RV Valves are now available from Chem Resist. The Plast-O-Matic RV valve performs several roles including as back pressure valves, bypass relief valves and back pressure regulating valves. The series RV valves are available in a choice of proven reliable designs including angle patterns with a moulded PTFE shaft for smooth operation, and in-line models which feature a rolling diaphragm which eliminates crystallisation problems.

The RV Valves are corrosion resistant and are used to protect equipment and systems against dangerous overpressures or sudden surges.

They prevent pumps from 'dead heading' due to unexpected shut-offs downstream and also maintain necessary back pressure in closed loop systems.

The valves also feature the patented Fail-Dry system.

This provides visual warning of seal malfunction and permits the valves to continue operation until a scheduled maintenance can be planned thereby avoiding a costly shut-down.

Further adding to the flexibility of this valve, it is available in a range of body materials including PVC, CPVC, Polypropylene, PVDF and PTFE.

KV Process Controls have launched their new low power high pressure solenoid valve, the Compact Type 51 valve. The new design incorporates a smaller 6.8 watt solenoid and compact internal piston assembly. The type 51 replaces the type 50, which has been used for general industrial applications in water treatment and OEM machine building.

It has a brass body, available form G1/4 to G1, with NBR seals and is internally pilot operated for pressures from 0.5 to 40bar.

KV Process Controls introduce a high-pressure solenoid valve which is a stainless steel 2/2 way pilot operated piston valve, especially developed for natural gas and hydrogen filling stations
CNG and Hydrogen gas filling valves KV Process Controls have introduced a high-pressure solenoid valve Type 2/529 which is a stainless steel 2/2 way pilot operated piston valve, for pressures up to 300bar, especially developed for natural gas and hydrogen filling stations. A special three or six position solenoid manifold has been developed for natural gas stations for the refuelling of vehicles with natural gas with integral pressure controls added to the block. The valve is available with connection sizes G1/4-G2 with a seat diameter of 6 to 50 mm.
ATEX EEx em II T4 approved coils are also available with this valve range.

Valve manufacturer Thompson Valves has secured a major order for its Maxseal solenoid valves from a key French EPC company, Cegelec
An order for nearly 700 Maxseal solenoid valves has been received by Thompson Valves following the Cegelec success of winning a systems upgrade project. Maxseal was chosen to supply its hazardous area solenoids for use on the Bab and Asab fields in Abu Dhabi. The Maxseal solenoid valve with its class H-coil insulation and stainless steel coil housing provided as standard make the IC04 range perfectly suited to the harsh conditions experienced in Adu Dhabi.
The contract consists of both low power direct lift and pilot operated solenoid valves in three port, two position and five port, two position configurations.
This latest order follows the success earlier this year in winning significant orders for the Dragon LNG receiving terminal, Golfinho FPSO and the Kerisi / Hiu Oil and Gas field development.
This deal confirms the Maxseal continuing success in promoting its world renowned brand of solenoid valves to major onshore and offshore oil, gas and petrochemical developments.

New safety relief valve with opening pressures of up to 100 bar is now available from gas technology specialist Witt, with TUV certification

Gas technology specialist Witt is now offering their popular safety relief valves with opening pressures of up to 100 bar. On the manual venting version a function test can be performed without dismantling, after the valve has been fitted. Until now these spring-loaded, direct-acting safety relief valves were only available for opening pressures of 0.5 to 45 bar.

The new models in the SV809/810 range are suitable for all pressure levels between 45 and 100 bar.

In addition the Type SV810 features manual venting, to enable a safety test to be performed after the valve has been fitted.

Safety relief valves are required to vent excess pressures in receivers/vessels, pipelines and other equipment.

Light in weight at around 260g, this safety valve from Witt is suitable for all technical gases.

The opening pressure can be set individually by Witt to meet on-site requirements.

The valves, which are available in brass or stainless steel, can be fitted in any position or orientation and their compact size means that they are easy to install.

Witt supply the new safety relief valves with a range of inlet connections, a protective dust cap and an optional condensation outlet.

These models comply with the Pressure Equipment Directive 97/23/EG Modules B and F, have TUV certification and, depending on gas type and valve seal, function within a temperature range of -196 C to +300 C.

The original 'smaller' versions with a maximum opening pressure of up to 45 bar are still available.

A discussion on the correct sizing of valves in process industry operations, which is essential for precision, quality and safety: oversizing is as bad in its effects as undersizing! 'Sizing valves correctly is essential for precision, quality and safety in process industry operations!' says Steve Meadows of Asco Joucomatic. The precision and quality demanded in process operations today mean that the importance of sizing process valves correctly is paramount. What is not acceptable is the traditional 'rule-of-thumb' method where the valve is oversized 'just to be on the safe side': in fact, experience shows that oversizing is as bad in its effects as undersizing.

The pitfalls with undersizing are many, including the inability to meet the desired flow requirements; the flashing of liquids to vapours on the outlet side of the valve; a fall in the outlet pressure; and substantial pressure losses in the piping system.

With oversizing, the user is faced with the unnecessary cost of oversized equipment and then has to cope with a number of problems, many of which can impair the operational life of the valves.

These include: variable or erratic control of flow through the valve; oscillation of internal parts to maintain required internal pressure, caused by lack of flow; erratic operation, such as failure to shift position; finally, in some designs, erosion of valve seats, because they operate in the nearly closed position.

In general, the best approach to avoid the problems of under and oversizing is to know as many of the conditions surrounding the application as possible.

The first parameter is the flow required: in cubic metres per hour (m3/h) for liquids; Normal cubic metres per hour (nm3/h) for gases and kilogram per hour (kg/h) for steam.

These flow figures can be obtained simply by asking the user his requirements; however, to avoid mistakes it is far better to refer to more concrete data such as nameplates on pumping equipment, boiler room charts or calculations.

The second parameter is the inlet pressure (P1); this is obtained from the source of the supply, or, better still, determined by placing a pressure gauge near the valve inlet.

The output pressure (P2) can also be obtained by gauge observations, but is usually tied-in with specifications regarding allowable system pressure drop.

However, if both the inlet pressure and the pressure drop are known, then the outlet pressure is easy to determine.

The size of the pressure drop (DP) across process valves is particularly important in large or complicated systems.

It is desirable to keep the figure to a minimum, and often the customer will have definite specifications concerning the factor.

Of course, if the valve is discharging to atmosphere, the pressure drop is equal to the inlet pressure, when dealing with liquids.

However, when sizing valves for use with gases and steam, although the valve may be discharging to atmosphere, only 50 percent of the inlet pressure can be used for calculation purposes in manufacturer provided formulae (commonly called the critical pressure drop).

In all other cases the pressure drop is, the difference between inlet and outlet pressures.

Determining the pressure drop also has implications where valves have a stated 'minimum operating pressure differential' - a term which is often misunderstood.

Certain pilot operated valves function by differential pressures created internally by 'pilot' and 'bleed' arrangements.

This differential is measured as the difference between inlet and outlet conditions on all valve constructions.

If pressure conditions are not known, but only flow information, we can use manufacturer-supplied graphs or formulae to solve the resulting pressure drop.

If this is less than the assigned minimum differential, then the valve is oversized.

In these situations, a valve with a lower minimum operating pressure differential should be employed or, alternatively, a smaller valve with a more closely defined Kv factor; Kv is the flow coefficient in cubic metres per hour or litres per minute.

Also useful to the process engineer engaged in valve selection is the converse of the minimum operating pressure differential.

When a valve is closed, the supply pressure is present at the inlet port only.

This is the pressure the valve has to open against: the pressure the electrical solenoid has to overcome to open the valve and allow flow to occur.

This pressure is called maximum operating pressure differential or simply 'MOPD'.

The value given for this in manufacturer's catalogues must be equal to or greater than the maximum pressure at the supply port at which the valve must open.

This is not always the same for different types of fluid, and AC actuated valves usually have higher pressure ratings than DC valves.

Strictly speaking, the MOPD is the maximum pressure drop across the valve when the valve is closed.

If there is a pressure at the outlet port when the valve has to open, this could be subtracted from the inlet pressure to arrive at the MOPD.

However, if at some time a zero pressure is present at the outlet, the valve will have to open at the pressure at the inlet, which may be too high, causing possible coil burnout on an AC source.

Therefore, the supply pressure is considered as the MOPD in conservative designs.

Full information regarding the Asco Joucomatic comprehensive range of solenoid and pressure operated valves for fluid control is contained within a new catalogue produced by the company.

Free copies of the catalogue are available on application to the Asco Joucomatic marketing department.

KV Process Controls have introduced a high-temperature and high pressure solenoid valve Type 2/164, a stainless steel 2/2-way piston valve. The valve can operate with zero differential pressure and is suitable for a pressure range of 0 to 40 bar. It has metal to metal sealing and is leak tested in accordance with leakage rate 3 DIN 3230, part 3.

The valve is available with connection sizes G1/4 to G2 and DN15 to DN100.

The valve was originally developed for blast furnace and steel production applications, and has a temperature range up to +300C with pressure capability up to 40bar.

A new high-pressure stainless steel solenoid valve is a 2/2 way pilot operated piston valve developed for fire fighting industry 'Water Mist' systems, with a pressure range up to 200 bar

KV Process Controls has introduced a high-pressure stainless steel solenoid valve Type 2/040 which is a 2/2 way pilot operated piston valve especially developed for fire fighting industry 'Water Mist' systems, with a high pressure range up to 200 bar. They are also used for water hydraulics. The valve is available with connection sizes G5/4-G2 with a seat diameter of DN32 to DN50, and is fitted with a manual override to help during commissioning and servicing.

The valve can be mounted in any orientation ATEX EEx em II T4 approved coils available with this valve range.