Schubert & Salzer

Schubert & Salzer develops, produces and distributes highly precise industrial control and stop valves which are applied in the process industry. Whether it is in the production of chemical or pharmaceutical products, food and beverage processing or the production of plastics, steel, paper or glass, as well as in the textile industry – in short, wherever liquid or gaseous flows need to be controlled, Schubert & Salzer valves are applicable.

Schubert & Salzer control and stop valves are amongst the most efficient on today’s market when it comes to energy consumption, durability and noise pollution. Their compact design and high control accuracy ensure low installation and maintenance requirements as well as high operational and process reliability with exceptionally long service lives.

Seat valves by Schubert & Salzer

Seat valves are the extremely reliable allrounders in the valve technology segment. This robust valve design with pneumatic or motorised actuators offers a high numer of maintenance free cycles in difficult on/off and control applications such as steam, gaseous media and contaminated liquids. They also do not cause any water hammers when installed to close against the media flow. The Schubert & Salzer seat valves are made of stainless steel or red brass. All are designed with a variety of end connections and are suitable for a wide temperature range.

Design principle seat valves

The shut-off device in Schubert & Salzer seat valves comprises a plug with a seal that seals against the seat. The use of a control plug enables the flow to be reduced depending on the valve opening. The pneumatic or linear actuators that are used are connected to the valve plug by means of a piston rod and they work independently from the operating medium. The dynamic sealing of the piston rod is realised by a self-adjusting packing. Seat valves can be flowed through from both directions, whereat in case of liquids, the preference is to close against the plug, in order to avoid water hammers and pressure peaks.

The advantages of seat valves

  • Robust and compact valve allrounder
  • High switching performance and wear resistance
  • Reliable shut-off function
  • No water hammers when closing against the media flow
  • High degree of tightness, low leakage
  • Wide operating temperature range
  • Simple insulation, low heat losses
  • High KVS value
  • Easy to install and maintain

The sliding gate valve principle by Schubert & Salzer

This is how easy control can be. Over 40 years ago, Schubert & Salzer Control Systems took a new approach in control valves. We developed the sliding gate control valve: a handy, light and highly accurate valve. It operates based on a principle that had already excited Leonardo Da Vinci. Even today, it satisfies the most challenging requirements that are placed on a control valve.

Design principle sliding gate valves

The sliding gate valves are characterised by a special throttle device in the functional unit that merely comprises two slotted disks that slide over each other and seal against each other. One sealing disc that is fitted in the housing perpendicular to the direction of flow has a predefined number of transverse slots. The second disc that is torque-proof and has the same arrangement of slots is moved perpendicular to the other one, this thereby changing the flow cross-section. The applied pressure differential presses the movable disc against the stationary disc.

The advantages of sliding gate valves

  • Low actuation forces, compact design, low weight
  • Long service life, minimal wear, low operating costs
  • Precise control with high dynamics
  • High cycle performance with very short cycle times
  • High KVS values, easily exchangeable
  • Low noise emission and no cavitation sensitivity
  • High degree of tightness, low leakage due to the functional principle
  • Simple design, easy to install and maintain
  • Reduced energy consumption and low insulation losses

Sliding gate valve – Efficiency

The outstanding feature of the sliding gate valve is the actuating force which is about just 10% of that needed to actuate a globe valve of the same nominal size and the same differential pressure. This permits the use of much smaller actuators even though both designs of the same nominal size have about the same flow rate! This beneficial feature stems from the fact that, in the sliding gate valve, closure is trans- verse to the direction of flow and not against it, as with the globe valve.

Sliding gate valve – Cavitation

A high rate of flow through the narrowest cross section of a valve will lower the local pressure below the vapour pressure of the liquid. Vapour bubbles form which then collapse in the regions of higher pressure. When they come into contact with solid boundaries (valve body), the imploding bubbles can cause damage. In the case of a sliding gate valve, these dangerous cavitation zones are external, or more accurately, they are located about 1 – 2 m beyond the valve. The cavitation bubbles then collapse around the centre of the pipeline where they can cause no harm.

Sliding gate valve – Vitality

Sliding gate valves are significantly „faster“ than conventional control valves. This can be shown using the frequency response when the set point value to an installed positioner is taken as the input value and the resulting stroke amplitude as the output value. The progression of the frequency response affects the standard of control of the entire control circuit.

Sliding gate valve – Weight

The low actuating force and short stroke allow the use of smaller actuators. Coupled with the space-saving wafer construction, weight and in-stallation dimensions are minimised, particularly in the mid to large nominal sizes. This translates into about 150 kg for a seat globe valve in DN 150, whereas a sliding gate valve of the same nominal size weighs a mere 15 kg!

Ball sector valves from Schubert & Salzer

The ball sector valves of Schubert & Salzer are used especially for dirty, abrasive, and pasty media in a variety of demanding on/off and control applications. This valve design is characterized by an extremely wide rangeability and a high flow capacity.

The special design of the ball sector valve enables the trunnions to absorb the entire force of the flowing media, which means very little actuating force needs to be generated by the pneumatic and electric drives.

Design principle ball sector valves

The key element of these on/off and control valves is a ball sector that can rotate by 90° and is used as a flow control element. Even under the toughest operating conditions, the ball sector seals the media using a simple, replaceable seat ring in the body. One part of the ball sector serves to shut off the valve, and the other has a hole with a diameter that normally corresponds to about 80% of the nominal size of the valve. To avoid effects of thermal or mechanical stresses, the bearings and the shaft seal are mounted in swiveling bearing bushings in the body. The shaft is sealed using a self-adjusting PTFE packing with an integrated spring element that protects the bearing against media particles. Ball sector valves have centric bearings and stable trunnions. This allows the ball sector to maintain constant contact with the valve seat seal while it is rotating. Changes in the differential pressure do only have a minor influence on the constant actuation torque.

The advantages of ball sector valves

  • Minimal wear even with contaminated, abrasive and pasty media
  • Precise control over a large control range
  • Low actuation forces due to shaft journals with bearings
  • High KVS value
  • Robust and compact design
  • Long service life, low operating costs
  • Simple maintenance and repair
  • No flow deflection
  • No draining of paper stock due to elliptical flow geometry

Wear resistance

Ball sector valves are frequently compared to rotary globe valves due to their design. The key difference between ball sector valves and rotary globe valves is the type of bearing. In general, rotary globe valves are equipped with an eccentric bearing. This causes the shut-off element to lift off the valve seat when the valve is opened. The result is that the sealing surfaces are continuously exposed to abrasive media when the valve is partially or fully open. For suspensions containing solid particles, the medium can get between the ball or plug and the seal ring, damage the surfaces, and cause leaks. Ball sector valves have centric bearings, which means the ball sector does not loose contact with the valve seat when rotating. Deposits on the surface of the ball sector are wiped off by the seat ring, and solids cannot get stuck between the valve seat ring and ball sector when the valve is closed.

Life span

The intelligent design of the seals in our ball sector valves, in combination with various materials and surface treatments for the ball sector and valve seat, form the basis for long life spans and reliable operation, especially in applications with abrasive, highly viscous, or fibrous media.

Segmented disc valves and Segmented disc orifices by Schubert & Salzer

Segmented Disc valves by Schubert & Salzer offer a perfect and variable control with high precision over a wide flow range. Due to the robust design and the bi-directional flow capability, segmented disc valves are suitable for fluids as well as vapours, even if these are contaminated by particles. The wide range of applications includes areas such as building materials, chemical and power plants, pipelines, water supply and disposal, as well as shipbuilding. An ingeniously simple but effective valve design!

Design principle of segmented disc valves

Segmented disc valves work on a very simple but effective principle.

The central throttling element – the segment discs that glide and seal against each other – are positioned in the valve body perpendicular to the flow direction. On a non-rotatable aligned segment disc whose geometry determines the flow rate and characteristic, a movable disc having the same number of segments is shifted by a tangentially engaging rod in such a way that the free cross-sectional area of the segments changes continuously.The movable segment disc is constantly pressed onto the fixed disc by a spring assembly regardless of the prevailing pressure difference. As a result, the flow direction is variable and the valve can be installed in any position.

This special design makes segment disk valves one of the few valves that combine control precision even in extreme operating conditions with a high seal tightness and very low exposure to wear.

The advantages of segmented disc valve

  • Low actuation forces, compact design, low weight
  • Long service life, minimal wear, low operating costs
  • Robust design, high resistance to slightly contaminated media
  • Bi-directional flow
  • Precise control
  • High KVS values
  • Low noise emission and non-sensitive to cavitation
  • High degree of tightness, low leakage due to the functional principle
  • Reduced energy consumption and low insulation loss
  • Segmented disc orifices

Adjustable orifice for the precise adjustment of a defined flow.

  • Adjustable while installed
  • Defined characteristics
  • End positions
  • Space-saving wafer design
  • ​​​​​​Low weight
  • ​​​​​​​Low-noise operation
  • ​​​​​​​High KVS values

Sanitary valves by Schubert & Salzer

Cleanliness or cleanability respectively is one of the highest priorities in many industries or is becoming increasingly important. Aseptic valves from Schubert & Salzer meet the highest requirements with maximum performance. In terms of control accuracy, flow chraracteristics and the elimination of dead spaces, particularly at the clamping points, the product design of this aseptic valve series clearly stands out from that of conventional hygienic valves.

Design principle sanitary valves

The demand for absolute cleanability in pharmaceutical and food processes depends directly on the flow conditions. In a nutshell, this means: the higher the flow velocity, the higher the wall shear stress on the surfaces in contact with the fluid and thus the greater the cleaning effect. A special EPDM diaphragm with a PTFE film coated on the process side separates the process chamber from the valve actuator.

The valve body is manufactured from pore-free stainless steel 1.4435 barstock material, finely turned or electropolished with roughness depths from Ra < 0.6 µm to Ra < 0.25 µm. The control plugs made of PEEK are FDA-compliant and meet the requirements of the USP Class VI, of the EU regulation 1935/2004 and the new plastics regulation 10/2011.

For inspections, or if a repair should be necessary, the aseptic right angle valve can be opened easily and quickly thanks to a clamp connection between valve and actuator. This valve series is characterized by compact pneumatic piston and diaphragm actuators combined with the proven digital Schubert & Salzer TopMounted positioner (optionally made entirely of stainless steel).

The advantages of sanitary valves

  • EHEDG-certified
  • Valve execution according to Directives (EC) 1935/2004 and (EU) 10/2011
  • FDA-compliant
  • USP Class VI
  • Design tailored consistently for good cleanability
  • Made from pore-free stainless steel barstock material
  • High rangeability 50:1 and unusually large control range
  • Simple maintenance, few wearing parts

Pinch valves and diaphragm valves by Schubert & Salzer

In contrast to other valve designs, very few components come into contact with the operating medium in the pinch valves and diaphragm valves. Long service life, reliability, safety and resistance to aggressive and abrasive media, combined with the excellent control performance of the top-mounted digital positioner, result in an optimal control valve with minimal maintenance and low operating costs.

Schubert & Salzer pinch valves and diaphragm valves are suitable for safe shut-off and precise control in chemistry, cosmetics, environmental technology and water treatment, as well as in electroplating or in food and beverage production. The pinch valves for endless tubes meet the highest hygienic requirements and offer an interesting and modern alternative to other valve designs. The pinch valves with metal body are used for low hygienic requirements; the straight valve passage is particularly advantageous for dirty, abrasive and viscous media.

Design principle of pinch and diaphragm valves

Schubert & Salzer pinch valves and diaphragm valves use the elasticity of high-performance polymers as a throttle. Pneumatic actuators compress the tubes fixed in the valve body or inserted endless tubes through specially designed pressure pieces. Due to the spring reset in the actuator and the operating fluids itself, the pinch valves and diaphragm valves move to the respective safety position or desired valve position.

Advantages of pinch valves and diaphragm valves

  • Robust and simple design
  • Minimal wear even with contaminated, abrasive and pasty media
  • Precise control
  • Reliable shut-off function
  • High tightness, low leakage
  • High flow coefficient (KV) values
  • Simple maintenance and repair
  • No flow deflection

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