Special Connections Screw threads

3 Port Rotary Unions

These are manufactured on a special basis but can at times be manufactured using the basic bearing housing and main seal from any of the standard Rotary Union range shown in this technical manual.

The illustration on the right shows a typical construction using two rotating centre tubes for 3 flow channels. We use Filton Bellows Seals or Filton Mechanical Seals, dependant upon working conditions, between each flow channel. If it is essential to prevent any “cross talk” between channels then a double seal having a bleed to atmosphere can be incorporated.

Piggy back rotary unions

At times it can be useful with multi-flow channels with different fluids if complete separation can be made.

The adjacent illustration shows a combined unit having two channels for hydraulic oil and piggy back on the outboard end, a Rotary (P.N.) Union for a pneumatic service.
It is possible to apply this principle to more than three channels, we have designed and manufactured six channel main units with two channel Rotary Unions piggy backed, making eight channels available in total.
Raccords rotatifs montés en tandem

Liquid bottling/canning – Rotary Unions

For the bottling and canning of beer, mineral water and soft drinks rotary machines are utilised which need specially designed Rotary Unions.

Multi-channel systems are generally used with facilities for compressed air, carbon dioxide, nitrogen and C.I.P. (cleaning in place) systems. The illustration on the left is a typical example having connections for C.I.P. compressed air, carbon dioxide and on the top an electrical slip ring system for instrumentation and control.
We can provide connections for any of the standard C.I.P. systems including RJT, ISS, DIN or TRICLOVER.

Multi port rotary unions

Although, in the main, the applications for Rotary Unions are covered by our standard range, there are many times when the machinery specification is impossible to satisfy without resorting to a special multi-channel design.


The Multi Port Rotary Unions we have provided have included services for cooling, heating, hydraulics, pneumatics and vacuum.


The illustration on the left shows a typical construction of a six channel un
it built on a sectioned body basis with a tie bar system. Solid body designs are also used dependant on the working specification. We have had many years experience in designing and manufacturing Multi Port Rotary Unions in a wide range of materials of construction including aluminium, bronze, carbon steel, stainless steel and nickel alloys.

There are times when there is a requirement for the rotary transfer of electrical services as well as the services indicated in the previous paragraph. We can design in this facility if required whether it be for power slip rings and brushes or for instrumentation purposes.

Overshaft rotary unions

All of the standard Rotary Unions in this technical manual are for connecting to the end of a rotating shaft. There are times when end access is impossible and the only way to transfer services is at some point along the shaft.

The illustration on the right is a typical design for an Overshaft Rotary Union. The type shown is for two services passing into and axially along the machine shaft.
We can also provide a design which incorporates the rotary connection into the Rotary Union sleeve for transferring services externally along the shaft.
We recommend that every effort should be made to obtain shaft end access to use standard designs as Overshaft Rotary Unions are costly and can require major machinery dismantling for servicing purposes.