Special Connections

1) Screw Threads

The standard connection threads are ‘G’ pipe threads to BS.2779 and ISO.288/1 (formerly B.S.P. Parallel). A number of variations are available depending on machine requirements including some of the more common alternatives that are listed below in the charts (add the required code to the suffix of the part number).  

 Notes:

 (i)  If an alternative female spindle thread is required for the spindle thread ‘A’, add
 the prefix ‘F’ to the appropriate thread code.

 (ii) ‘G’ pipe threads are to BS.2779 and ISO 228/1 (formerly B.S.P. parallel).

(iii) ‘R’ pipe threads are to BS.21 and ISO 7/1 (formerly B.S.P. taper).

All rotary connections threads (indicated by dimension ‘A’), can be provided with RH or LH threads to suit the direction of rotation. For other variations, please contact us. 

2) Flanges

For applications where standard threaded connections are unsuitable, rotary unions with flanged interfaces are also available. Some examples where this might occur include: 

• Applications in which the shaft is regularly changing direction from
clockwise to anti-clockwise. The rotation could potentially unscrew a threaded unit.

• Situations where the temperature exceeds 200oC. For high temperature applications, a range of flanged rotary H.T.F. unions are also available - please contact us for more information.

• Rotary union model sizes including 125 (5’) and 150 (6’) where the use of a flange facilitates the ease of installation, maintenance and removal.

The most common types of spindle flange designs are shown in the diagram to the right. Specials can be manufactured to suit virtually any shaft end dimensions that may be required and, if flanges are required for the stationary connections, these can be provided to any of the National or International specifications including: A.F.N.O.R., A.N.S.I., BS.10, BS.1560, BS.4504, D.I.N. and I.S.O. For all new design work where equipment is to be used in the European community, we recommend in particular the BS.4504 standard.

In the case of applications in which the flange itself rotates, special care must be taken during the design stage as concentric mounting is essential. These rotating flanges can be based on any of the standard flange specifications, but they will require a concentric location spigot or recess. All rotary connections threads (indicated by dimension ‘A’), can be provided with RH or LH threads to suit the direction of rotation.

The most common spindle flange sizes are listed in the chart below. Specials can be manufactured to suit virtually any shaft end dimension and there are a number of custom options available. 

For additional information about flange options,
please contact us.

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