Jun 4 2009
Subsea valve solutions provider Oliver Valvetek Ltd has introduced an innovative in-line gate valve to their existing comprehensive product range. The concept was developed in conjunction with a leading subsea tree manufacturer based in the North of England who was introducing a new generation stock horizontal tree to their product range.
"The design criterion for the in-line product was extremely demanding" explained design engineer Bill Makin. "Space limitations dictated that the inlet flange had to be on the same centreline as the actuator drive stem and the valve had to achieve a maximum working pressure of 15,000psi whilst operating at depths of 10,000ft below sea level."
As space was very limited around the flange connection, allowing hydraulic tooling access to the flange bolts, whilst maintaining a robust transition between valve and flange, became the greatest challenge. The solution was fine tuned using Oliver Valvetek's recently introduced Solidworks 3D modelling package with its finite element suite of software.
"The complexity of the geometry at the rear of the flange meant that, for the first time in our history, we supplied not only a drawing but a solid model IGES file to our machine shops," said Mr Makin. "This meant we could achieve full integration with state of the art six axis machine centres.
"Part of the development programme was to interface a hydraulic torque head onto the flange bolts in order to check tooling clearances. This was assisted with the free loan of tooling from the Northumberland based company Hire Torque Ltd, and our thanks go to them."
The two main advantages of the in-line gate valve are space and cost savings, with the footprint of the valve being significantly smaller than conventional valves. This results in more compact tree bodies and direct material cost savings. Additionally the conventional valve make-up requires a significant 90 degree flange block to achieve the same orientation requirements which now becomes obsolete providing one less leak path and further direct material cost savings.