Copes Vulcan in Australia
Desuperheaters
The PRDS is a single seat balanced Pressure Reducing and Desuperheating valve. Situated on the lower portion of the throttle plug, operating in a rigid guide, is a balancing piston. The plug also incorporates a balancing port between upstream and downstream conditions. Using this technique, the required actuator forces are reduced and the small flow passing into the downstream pipework ensures that thermal shocks are minimized, as the pipework is kept warm even when the valve is in the closed position.
A shroud is provided above the coolant annulus to protect the body from possible high velocity coolant impingement, which could give rise to localised thermal shock. The shroud is retained by the upper plug guide.
Construction - In the low noise HUSH trim, the conventional plug is replaced by a balanced cage guided plug which operates in an inner replaceable cage. This cage incorporates an integral seat and is screwed and locked into the body web. The many holes in the cage are arranged in a rising spiral to give a continuous infinite characteristic.
Located around the inner cage are a series of concentric cylinders, each having the same number of holes as the inner cage. The holes are progressively enlarged in diameter from the innermost to the outermost cylinder. The cylinders are arranged to give successive overlapping of the holes followed by expansion chambers. This is HUSH trim.
A coolant annulus is created adjacent to the outer
sleeve where the coolant gains preheat from incoming vapor and is then admitted
to the low pressure zone after the outer sleeve. An outlet diffuser is included
to give a final pressure drop and to complete the atomization and
absorption of the coolant.
Please refer to our comprehensive table listing the performance of each Copes
Vulcan Desuperheaters by clicking [HERE]
