PROLOAD LIVE LOADING SYSTEM
New generation encapsulated disc spring system with defined compression length.
Typical problem
The stack of disc springs is too long for the of the available bolt length.
As a result usually the bolts need to be replaced which is time and cost consuming.
Solution
The PROLOAD Live Loading System screws on top of the bolt in a kind of cup form and giving thereby plenty of extra length to accommodate the uncompressed disc spring stack. This incorporates also an equal load of compression for thermal expansion of the valve. The springs cannot be overcompressed as the optimum compression length is set by the PROLOAD housing dimension.
A sideeffect of the system is that the disc springs slide instead on a thread on a smooth machined surface. Further they are encapsulated and protected against dirt and environmental impact.
Functional Description
When the packing or gasket settles in operation the springs maintain the gland pressure and the sealing force constant. The settling is shown by a small inspection gap at the bottom of the housing. At a routine inspection the PROLOAD Live Loading System is simply torqued down till the gap is closed.