Typical Mechanical Coupling Product Types

Couplings

Viking Johnson Dedicated Couplings

Viking Johnson dedicated straight couplings are used for joining pipes of: –

Fabricated in steel means Viking Johnson dedicated couplings can accommodate end user needs with respect to: –

When ordering Viking Johnson dedicated couplings, as a minimum the following information must be provided for each pipe being joined: –

Within the Viking Johnson dedicated coupling range there are variations of centre sleeve design, which is dependent on diameter / working pressure and selected at the discretion of Viking Johnson.  The standard sleeves do not have an integral centre register within the sleeve, enabling couplings to be slipped back along the pipe for pipe cleaning, repair and maintenance.

Viking Johnson Wide Tolerance Couplings

Viking Johnson wide tolerance couplings (e.g. MaxiFit, MegaFit, UltraGrip) are used for joining pipes of: –

With up to 34mm tolerance on the pipe outside diameter, Viking Johnson’s wide tolerance fittings offer: –

With working pressure of up to 16 bar on water, Viking Johnson’s wide tolerance fittings provide the ideal solution for both the repair and capital works schemes in the water sector.

Coupling Movement

When wide tolerance couplings are used to join pipes of different outside diameters, it is essential to ensure that the coupling cannot be forced along the smaller diameter pipe by internal pressure forces.  This does not normally apply to below ground service at moderate pressures but can be an issue in above ground applications where regular inspection of the coupling position against a previously applied mark is strongly recommended.

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Reducing / Stepped Couplings

Viking Johnson Dedicated Reducing / Stepped Couplings

Viking Johnson dedicated stepped / reducing couplings are used for joining pipes of: –

Fabricated in steel means Viking Johnson dedicated stepped / reducing couplings can accommodate end user needs with respect to: –

When ordering Viking Johnson dedicated stepped / reducing couplings, as a minimum the following information must be provided for each pipe being joined: –

Viking Johnson Wide Tolerance Stepped / Reducing Couplings

Viking Johnson wide tolerance Viking Johnson stepped / reducing couplings (e.g. MaxiStep, UltraGrip) are used for joining pipes of: –

With up to 34mm tolerance on the pipe outside diameter, Viking Johnson’s wide tolerance fittings offer: –

With working pressure of up to 16 bar on water, Viking Johnson’s wide tolerance fittings provide the ideal solution for both the repair and capital works schemes in the water sector.

Reducing / Stepped Coupling Sleeve Design

To accommodate the variety of sizes and combinations of pipe material found in the water network, the centre sleeve of stepped / reducing couplings will be one of the two basic designs: –

Expanded Sleeve; these are used when: –

Make Up Ring Sleeve (MUR); these are used when: –

Coupling Movement

When stepped / reducing couplings are used to join pipes of different outside diameters, it is essential to ensure that the coupling cannot be forced along the smaller diameter pipe by internal pressure forces.  This does not normally apply to stepped / reducing couplings using expanded sleeves in a below ground service at moderate pressures.  This is particularly important above ground and/or where a stepped coupling design uses the Make Up Ring (MUR) configuration.

Alternatively, the use of Viking Johnson’s UltraGrip restrained fittings offer a cost-effective solution that prevents the stepped coupling from sliding along the smaller pipe.

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Flange Adaptors

Viking Johnson Dedicated Flange Adaptors

Viking Johnson dedicated flange adaptors are used to connect plain-ended pipes to either to flanged pipe or to flanged valves / fittings.

Fabricated in steel means Viking Johnson dedicated flange adaptors can accommodate end user needs with respect to: –

When ordering Viking Johnson dedicated flange adaptors, as a minimum the following information must be provided: –

Viking Johnson Wide Tolerance Flange Adaptors

Viking Johnson wide tolerance flange adaptors (e.g. MaxiDaptor, MegaFit, UltraGrip) allow for connecting multiple pipe materials either to flanged pipe or to flanged valves / fittings.

With up to 34mm tolerance on the pipe outside diameter, Viking Johnson’s wide tolerance fittings offer: –

With working pressure of up to 16 bar on water, Viking Johnson’s wide tolerance fittings provide the ideal solution for both the repair and capital works schemes in the water sector.

Tied Flange Adaptors – Notching of End Ring

If a flange adaptor is to be used in a tied arrangement, depending on the pipe outside diameter and/or the flange drilling it may be necessary to notch the end ring to ensure sufficient clearance for the tie bars. If notified beforehand, Viking Johnson can incorporate notching of the end rings during manufacture.

As standard Viking Johnson will adopt the following rules for the number of notches in an end ring, and hence the number of tie rods that can be accommodated: –

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Flange Adaptor Configurations

The design of Viking Johnson flange adaptors varies according to the configuration of the flange nominal size / drilling specification and the outside diameter of the pipe on which the fitting is being used.  The following are the standard offerings: –

Straight Sleeve

This is the standard design offered that allows the flange adaptor to be fully slid over the pipe end for easy fitment on site.

If this design is being used with flanged fittings that have specific sealing face dimensions, the user needs to verify that they will be compatible with the sealing face dimensions of this product.  In the event they are not, then the “S” Bore configuration would be a better choice.

“S” or Full Bore Design

Flange adaptor with full bore flange faces are available, which are ideal for use with wafer style (butterfly) valves.  While these offer an increased sealing face the full bore does prevent the fitting from sliding fully over the pipe end; if required, longer sleeve options are available to increase the setting gap making for easier installation.

Expanded Sleeve Design

The Expanded Sleeve Design is specifically for use with very thick walled pipe such as asbestos cement or concrete and can also be used when the nominal sizes of the flange and the pipe are different (e.g. connecting DN350 (14″) pipe to a DN300 (12″) valve).