Page 84: of Maritime Reporter Magazine (October 2003)

Insulation, Pipes, Pumps & Valves

Walform M Plus: Leak Free pipe connections

For high pressure and low pressure applications

The Walform M Plus pipe connector system devel- oped by GKN Walterscheid in Germany and marketed exclusively in Great Britain by Stauff UK is designed to deliver a new dimension of safety and reliability to pipework systems for British Warships.

There were opportunities to introduce the latest con- nection technology for future builds, that would pro- vide significant performance improvements as well as cost reductions. Therefore the MoD (Navy) with Stauff and Walterscheid at Qinetic in Rosyth entered into the most exhaustive test program ever carried out on pipe work couplings by the M.o.D. At the end of the pro- gram Walform M was given full M.o.D. (Navy) approval for use on Cupro - Nickel 70 / 30 pipework for all future work.

The Components

The Walform M Plus connector system uses standard

DIN 2353 connector components i.e. malestuds, elbows, straight connectors etc.; but does not utilize the cutting ring (olive). Instead the tube is reshaped on the

Walform machine to replicate the 24-degree cone. This eliminates any potential for a leak path to be created in conditions of severe stress. The Walform Plus System has two versions: the M (metallic) seal or the WD (elastomeric seal). The latter provides for sealing to be enhanced with the use of a separate and replaceable profiled sealing ring. This is an additional feature that can be used when there is no inherent worry about the inclusion of polymer products.

Testing

A whole series of tests were undertaken: Proof

Pressure: Disassembly/Reassembly; Vacuum Gas;

Maximum Static Gas: Impulse; Vibration: Thermal

Cycle; Fire Test; Overtighten Test; Tensile Test; Deck

Shock; and Shock Test.

Probably the most significant of these was the shock test program, brief details of which are as follows:

A sample cross section of pipes were made up using 70/30cupro nickel tube and fitted with straight connec- tors and elbows. These pipes were then fitted to deck shock test equipment, pressurised to 300 bar and sub- jected to lOOg acceleration with maximum deflection (63.5mm). Then they were further fitted to shock test machines, pressurized to 300 bar and subjected to acceleration in both the vertical and horizontal axes, of firstly 200g - the required level for MOD acceptance, and in addition further tests up to 700g were success- fully carried out. At the completion of the testing pro- gram, despite considerable distortion of the pipework, including bending of the 38 mm dia. x 6.5 mm wall tube, all of the joints maintained a completely leak free integrity.

Application

For Warship and other military uses, the application of systems with a metal seal helps to avoid any of the operational problems sometimes associated with the long-term lay-up of joints with polymer seals.

The introduction and application development of this system has been carefully scrutinized by UK Defense departments and their contractors. The need for defense project suppliers to offer whole life guarantees and support for their equipment means that the long- term integrity offered by Walform M Plus will provide service life cost savings as well as initial installation cost reduction.

Because this system has been developed essentially as a commercial product, there are no premiums involved when using it for pipework systems at large.

This means that the use of the Walform product in everyday applications will offer huge benefits in terms of operating features. The inherent leak free properties as well as high operating pressures will ensure long life and minimum service costs.

For more information from Stauff UK

Circle 52 on Reader Service Card

VENTIQ Offers Innovative Approach to Cargo Tank Venting

Ventiq's new range of high velocity relief valves for tankers vessels, VQHV-

ISO, are designed to prevent passage of flames into cargo tanks carrying oil, product and chemical cargoes. The

VQHV-ISO is also designed to prevent over- and underpressure in a safe and simple way. Ventiq has taken the latest amendments issued by IMO into con- sideration and focuses on safe opera- tions and easy maintenance. Ventiq has developed a series of valves which are type approved by leading classification societies and the United States Coast

Guard, and meets the latest require- ments of ISO 15364:2000, SOLAS

Reg.59. IMO MSC 1009/677/373 and

API 2000.

The valve range provides safe venting to atmosphere to protect the tank against pressures above or below ambient. Its internal design avoids oscillation and hammering which could lead to prema- ture seat wear and flashback to the tank.

The complete unit is manufactured from acid resistant stainless steel, with easily replaceable seats. Valve functions to full stroke can be checked using a single lever. A removable circular inspection window, "fish-eye", allows for easy inside inspection of the valve for clogging, as well as for easy clean- ing. This window also works as a visual check of vacuum disc operation.

Function and safety are strongly empha- sized in the Ventiq design and manufac- turing process.

For more information from Ventiq

Circle 53 on Reader Service Card

The Test Platform 82 Maritime Reporter & Engineering News