Rotary Union

LATTY rotary unions are used to create a leak-tight link between a stationary pipe and a rotating pipe, whatever:

• the kind of fluid conveyed,
• the rotary speed,
• the range of the motion,
• the fluid temperature,
• the number of circuits,
• the cross-section of the circuit(s),
• the flow.

LATTY rotary unions or rotary joints apply :

• standards and directives (FDA, etc.),
• customer specific designs.

For many years, the GROUPE LATTY has been offering rotary unions of various types:

• with friction seals for gas or liquid applications,
• with mechanical seals with contact for liquid applications,
• with bellows for very high temperature applications.

These various criteria are considered to determine the type of union to be used

We use rotary union:

• for the transfer of liquid or gaseous substances,
• within a machine between stationary and rotary parts.

In almost all industrial sectors:

• mechanical construction and automobile,
• civil engineering,
• food processing,
• steel,
• mining, etc.

The metallic gaskets LATTYgraf REFLEX consists of:

• an active component made of expanded graphite to provide sealing efficiency,
• 2 precision-machined stainless steel outer rings used as compression limiters.

The specific pressure on the expanded graphite required to achieve gasket metal-to-metal contact and ensure tightness remains very stable. This stability at ambient and high temperatures is necessary for proper gasket operation when in metal to metal contact.

The various types of LATTYgraf REFLEX gaskets

• Gasket with double sealing face for special applications such as exchanger-type,
• Gasket for flanges with single or double recess,
• Gasket for valve bodies.

Specifications of the LATTYgraf REFLEX metallic gaskets :

• The sealing efficiency of LATTYgraf REFLEX is not affected by changes in pressure or temperature of the fluid to be sealed, even with rapid and significant changes.
• The stainless steel ring in contact with the flange faces absorbs the mechanical loads, while the highly elastic expanded graphite crown ensures leak-tight operation.
• Improved reliability of the bolted assemblies subjected to thermal stresses and preserved sealing efficiency in the event of upset conditions.
• Reduces the stresses on bolts, thus providing an extra margin to handle additional stresses due to temperature changes.
• Excellent repeatability guarantees the tightening components thanks to the low dispersion of the loads to be applied to the gasket to achieve leak-tight operation.
• Possible use, depending on the various parameters, of all machineable materials whose characteristics are compatible with the operating conditions.
• The compression limiter absorbs all the mechanical stresses due to pipework, thermal shocks, etc. while the active expanded graphite part remains low stresses mechanically.
• The outstanding elastic recovery of the tightly wound expanded graphite provides LATTYgraf REFLEX with a very high release capability. The recovery represents approx. 10% of the thickness of the compression limiter.

GROUPE LATTY’s PECODY  solution (Presse Etoupe à COmpression DYnamique), is the result of our experience in sealing with packings.

The PECODY solution allows us to optimise sealing in very demanding applications and under hostile conditions in which other sealing systems have reached their limits. It meets constraints, environmental standards and directives such as ATEX, FDA, EHEDG, EC 1935/2004, etc.

This technology has been developed by LATTY for companies requiring solutions for their specific process equipment:

• an optimisation of productivity,
• an optimisation of maintenance,
• improved individual protection in hazardous industries such as nuclear power and powdery materials or chemicals.

The confirmation of our knowhow in the sealing efficiency of packings allows us to offer alternatives that meet your requirements.

Our PECODY solution is proving to be very efficient with problematic substances such as

• abrasive,
• slurries,
• clogging,
• powders,
• toxic,
• flammable, explosive or oxidising environments.

PECODY operates according to the dynamic compression principle (calibration of the clamping force). PECODY data sheet

It is custom-mounted as a cartridge on machinery being designed or refurbished or to improve existing installations such as:

• mixers,
• stirrers,
• horizontal dryers,
• cookers,
• sterilizers,
• reactors, etc.

PECODY is both ergonomic and compact, which facilitates access for assembly, disassembly and maintenance operations, including in areas where access is difficult.

Advantages of PECODY    

• Suitable for abrasive and corrosive environments due to the chromium carbide coating.
• Limited frictions: prevents overheating and premature wear,
• Total interchangeability: packings, springs, sleeves, etc.
• Rapidity: reduces production downtime,
• Security: no time-consuming handling in hazardous, radioactive and dusty areas,
• Repair and renovation: programmable, rapid maintenance, without disconnecting the machine,
• Ergonomic models to facilitate access for assembly, disassembly and reconditioning operations,
• Compact for areas where access is difficult,
• Remotely controlled for hostile (thermal, contaminated, radioactive) environments,
• Execution possible in 2 parts for disassembly by radial opening.

GROUPE LATTY‘s cartridge boxes and ancillary systems are used to ensure the leak-free operation of equipment such as:

• reactors,
• filters,
• dryers,
• mixers, etc.

LATTYseal cartridge boxes, which comply with strict flange and shaft-end connection standards and are also suitable for CIP/SIP equipment, are used in the following industries:

• pharmaceuticals,
• food processing,
• cosmetics,
• fine chemicals, etc.

Cartridge boxes complying with the following certifications and directives:

• FDA,
• ATEX zones 1 and 2,
• EHEDG,
• ACS, etc.

The different types of cartridge box include:

• single cartridge boxes,
• double cartridge boxes.

As a result of tests carried out in our R&D laboratories, we have been able to optimise the friction rings on coated surfaces after various types of barrier fluids have flowed through them, to define the operating limits and to simulate shaft axial movements and deflection that occur on some machines.

SINGLE CARTRIDGE BOXES

During development of mechanical seals and after a number of tests, the  LATTY GROUP has validated a new “simplified” double-effect cartridge box for applications with chemicals and pharmaceuticals that can be adapted to agitators and filters at the top of tanks.
This design is based on a mechanical seal on the process side where the barrier fluid is sealed by friction rings on a coated surface rather than a second mechanical seal is often the case in conventional assemblies.This new mechanical seal reduces the purchasing costs as compared with a double-effect solution while ensuring an equivalent reliability and lifetime.
This single mechanical seal requires less headroom and offers various options, e.g. with or without ball bearings, with different drive systems, with different materials, and meets current construction standards (DIN 28138 – DIN 28141 – DIN 28154).
The  LATTY solution for cartridge boxes includes LATTYseal 4212 series mechanical seals and complies with the ATEX zone 1 and 2 directive and with FDA requirements.

DOUBLE CARTRIDGE BOXES

LATTY mechanical seals are designed for unbalanced cartridge applications that are independent of rotation direction.
The diversity of operating parameters, assembly constraints, environments and specification requirements makes each design unique.
Among the many available options are a drive mechanism, cooling flanges and friction materials, all of which comply with the ATEX directive.
Specific modifications can be undertaken by LATTY’s technical department. With our comprehensive databases, we can rapidly submit projects together with detailed descriptions.

ANCILLARY SYSTEMS

GROUPE LATTY has developed lubrication units that enable the barrier circuit to be fully serviced to double cartridges.

• Thermosyphon,
• Lubrication unit,
• Gas Control Panel (GCP).

Thermosyphons
Made of stainless steel, they ensure the flow of barrier fluids through LATTY cartridge boxes and other series of mechanical seals.

Lubrication units 
They simultaneously keep the seal box under pressure and regulate the barrier fluid temperature. They are suitable for all models and seal assembly types (double, tandem, etc.).

Gas Control Panels  (GCPs)
They ensure that the barrier gas (air or nitrogen) injected into the sealing system is kept under constant pressure and form a compact assembly contained in a polyester case.

All the components can be fully disassembled and placed inside an insulating box (IP 65) with a transparent polycarbonate door so that all components are visible.
All the components are designed to be operated in an industrial environment up to a  maximum temperature of 70°C.
All the pipes are semi-rigid with a tubular aluminium core protected on both sides by a polyethylene coating, the outer

coating being of high-density polyethylene (HD-PE).
The inlet and outlet connections are 1/4″ gas female. Filtration is provided by a coalescent 5-micron filter (standard supply) connected to an automatic drain and a 0 – 10 bar pressure reducer.
Remote monitoring of the minimum fluid pressure is ensured by means of a pressure switch.

Packings consist of several preformed rings with a fully controlled height under load, used in stuffing boxes.

Packings provide the following advantages:

• a reduction up to 30% of the friction, as a result of the presence of an agent that has been specifically developed by the GROUPE LATTY,
• optimisation of the number of rings,
• reduction of installation time for your maintenance teams,
• extension of the lifetime of your stuffing boxes,
• optimisation of your stocks,
• coding per packing.